Cause of Ragged-Looking Japanese Privet Leaves

Q. I have in front of my house 5 big shrubs. Unfortunately I have no idea what they are called. They are getting water over our irrigation system.Today I took a closer look to my shrubs and found all 5 shrubs in really bad condition.
1. The leafs are full of white, at the edge brown dents, but only on the upper side.
2. I've noticed a lot of bees around and inside one of the shrubs.Perhaps cutter bees but I don't have  circled bites on my leafs
3. On one shrub I have a small white net, perhaps a spider net?

Here are my questions: Can you tell me the name of my shrubs and do you have any idea what my problem is?

A. The plant you asked me to identify in the pictures is called wax leaf or Japanese privet. It is not a desert adapted plant so it should be managed the same as other plants which are not desert adapted. It is native to Japan and Korea and so it prefers non-desert soils, medium light intensity, cooler temperatures and rainfall.

It is planted quite a bit in our desert and it always tends to look a little bad because it doesn't like it here much. It prefers climates that are not desert. This is a plant that should not be grown in rock surface mulch but in the wood chip surface mulch instead.

The usual reasons for this plant to decline in appearance is because the soil declines or becomes mineralized because of the loss of organics in the soil over time. The other reason it may tend to look badly is because of poor irrigation management.

If rock surface mulch is surrounding these plants please pull it away from them down to bare soil. I would put about half a cubic foot of compost at the base of each plant and lightly work it into the soil and irrigate thoroughly.

Next, I would check to make sure the irrigation is working correctly and there are enough drip emitters for each plant. Each plant should have at least two drip emitters located about 12 inches from the main trunk.

I would apply about 3 to 4 inches of wood chip mulch, not bark mulch, around all of the plants. Remove by pruning any parts of the plant that are ugly in appearance.

Fertilize the plants once a year in January with an all-purpose tree and shrub fertilizer. The easiest way to apply it is put a handful of fertilizer next to each drip emitter and water it into the soil. Irrigate these plants as you would any other trees and shrubs that are non-desert plants.

Follow-up Q. So, your opinion is that all the white dents (scars) on the leafs are a  fertilizing and irrigation problem? I have no fungus or bugs? And also the cutter bees inside the shrub are not connected to the visual problems ? Should I buy some insecticide?

Followup A. I know it seems improbable that irrigation could cause leaf damage like some of what you are seeing and I agree that is not the only problem. However, my experience with wax leaf privet is that they are out of their climate zone when grown in Las Vegas and growing them here puts a lot of stress on these plants.

The way to decrease the stress on these plants is to give them better growing conditions. This means soil improvement, planting them in the right light and heat exposure in a landscape, using organic surface mulches to continually improve the soil and maintain soil moisture and elimination of rock surface mulches that tend to mineralize the soil.

Once you begin to improve their health and decrease their stress most of the problems that you see will disappear. Then we can start looking for other things that are causing problems to these plants but the major problem you are seeing is due to their environment, either natural or manmade.

We do not have a lot of disease and insect problems on these plants. The diseases that we do have on these plants are from watering too often and poor drainage of water from around the roots. If these same plants were grown in central Japan where they are native you would not see the majority of these problems.

Las Vegas is not central Japan. Create an environment in your home landscape that is closer to the environment where they originate; soils have higher organic matter, light intensity is less, temperatures are cooler, humidity is higher. Try to re-create as much of this environment as you possibly can in Las Vegas; plant on the north and east sides of buildings where they receive shade from late afternoon sun, add organic material back to the soil, avoid rock surface mulches, etc.

When growing plants in the desert that don't belong here you must try to find locations that emulate where they came from as closely as possible. Apply management practices that emulate their original envrionment. Insects and diseases are not the majority of the problems with this plant.

By the way, the attraction of bees to this plant is typically an indicator that one of the sap sucking insects that secrete honeydew is present; aphids, whiteflies, mealybugs or scales. The bee problem could be cleaned up with sprays of soap and water on the undersides of leaves. After the plants are in better health then start working on the bee problem.

Attention Embarq Emailers - Check Your Spam Folder for Responses from Me

Sometimes I receive emails from people using Embarg.com hosted by Century Link. I respond to these emails but I told that my email response is undeliverable. Please check your spam folder when looking for a response from me. Email address of the sender in this response was substituted with XXXXXXXX.

In the subject line of the email sent notification

Undelivered Mail Returned to Sender

*** ATTENTION ***

Your e-mail is being returned to you because there was a problem with its delivery. The reason your mail is being returned to you is listed in the section labeled: "----- The delivery status notification errors -----".

The line beginning with "Diagnostic-Code:" describes the specific reason your e-mail could not be delivered.  The following lines contains the RFC822 header of the original email message.

Please direct further questions regarding this message to your e-mail administrator.

--AOL Postmaster

----- The delivery status notification errors -----

<XXXXXXXXX@embarqmail.com>: host mx.centurylink.net[205.219.233.5] said: 554

    5.7.1 [P4] Message blocked due to spam content in the message. (in reply to end of DATA command)

Marble-Sized Mud Balls on Plant Leaves a Good Thing

Q. I sent you some pictures of a round object about the size of a large marble with an entry hole in it. I found it attached to the leaf of a cats claw leaf in my backyard of my Summerlin home.  I only have found one so I am not worried about lots of pests from this one vessel.

Potter wasp nest on cats claw vine leaf

A. I think this hard, mud-like ball with a hole in it, attached to a leaf, was left behind by a mason wasp. The mason wasp is also sometimes called a Potter wasp because of these round mud balls with a hole in it that resemble pottery. It has been theorized that Native Americans based some pottery designs from the mud balls left behind by Potter wasps.

            Wasps are generally divided into two categories; those that live with other wasps in a community which are called “social” wasps, and those wasp that live by themselves which are termed “solitary” wasps.

            Potter wasps are considered solitary; they live alone and build this mud nest for a single, solitary offspring. After building this pottery-like nest, the female finds a grub that will fit in it, paralyzes it by stinging and places it in the nest along with an egg. The developing youngster uses it for food.

            Potter wasps are not aggressive towards humans or other large animals unless they are provoked then they can sting multiple times without dying unlike a bee. They would be considered a beneficial insect in the garden area.

            Consider Potter wasp mud nests as one of the “good things” in gardens and landscapes. Just give the adult wasp its own space.

You can learn more about them here

https://polinizador.wordpress.com/2011/04/12/potter-wasps-and-mason-wasps/

https://en.wikipedia.org/wiki/Potter_wasp

Gardenia Needs Container and Extra Care in the Desert

Q. I love Veithcii Gardenia and I noticed that a local nursery has them for $10 for a 5 gallon plant. How do you keep the plant alive in the winter in Las Vegas and should it remain in a container and not in the ground? I have seen two of these plants in containers in Sun City Summerlin under a tree blooming profusely in the summer.

Gardenia In Las Vegas in filtered light

A. “Veithcii” is a popular selection or variety that has a longer bloom period than some others. Gardenias are grown by a number of home gardeners in our desert but you are right, they don't belong here so we have to put them in the right location and amend the heck out of that soil if we want them to do well.

            . It is best if they are grown in containers rather than growing them in garden soil. A good spot would be in filtered light which is what you would get growing them under some trees for protection from intense sunlight.

            Gardenias in general perform best in a bright northerly or easterly exposure. The soil should be 50% compost or at least high in organic matter. You can grow them in the ground but they will be more difficult to manage because the soil will slowly revert back to desert soil unless you continually add compost to the soil surface.

More about this Gardenia from Monrovia Wholesale Nursery

            It is also important to put a two or 3 inch layer of wood chips. I would use two drip emitters and never let the soil get overly dry. Fertilize 3 to 4 times a year and add a good iron chelate to the early spring application of fertilizer.

            The important things to remember is having a good soil, the proper exposure to light and irrigation frequency. The container should allow for drainage of water and you should see a small amount of water exit the container every time you irrigate. Good luck!

How to Rehabilitate Japanese Black Pine

Q. Are Black Pine, California Christmas Tree and Thumbergii all the same plant? I have 2 trees that are important in my landscape and have been doing well for several years. They were neglected recently so there is no place for deep watering and not fertilized in 2015. There is sap coming from the trunk. Should I try to rehabilitate them or replace them?

Japanese Black Pine

A. Japanese black pine is Pinus thunbergii so Thunbergii probably refers to Japanese black pine. I do not know if it is called California Christmas tree but I doubt it because Japanese black pine has a very unusual form making it a specimen plant in the landscape. It does not have the Christmas tree shape.

          Most of the textbooks say Japanese black pine tolerates alkaline soils but I have not really found them to be very tolerant of the hot desert and our soils. Many of them have been planted in Las Vegas but very few are still around which tells me many were removed.

          If you have Japanese black pine they are characteristically slow in growth and have a very distinguished form that adds character to a landscape. If you are looking for a Christmas tree pine this is not going to be it.

          They are slow-growing. If they have been neglected and do not look good they will rehabilitate very slowly. 

          Soil applied systemic insecticides that control borers would be a good if the trees actually have them. Pines can be “sappy” so make sure it is borers before you make the application. Wounding of the trunk and limbs can also cause them to bleed sap like borer damage.

          If you choose to rehabilitate them, put tree wells around the trunk about 2 feet in diameter to hold irrigation water. Give them a deep soaking with a hose once a month along with their normal irrigations.

          Fertilize them with 16–16–16 once a year in the early spring or apply it now if they haven't been fertilized this year. Punch some holes in the soil 2 to 4 feet from the trunk to a depth of eight or 10 inches. Put a handful of fertilizer in each of the holes and water them twice to activate the fertilizer and move it into the tree.

          Expect a very slow recovery if you choose to rehabilitate them. If they look bad now, I would suggest that you consider replacing them with something that you really like and can get instant gratification.

Air Pruning of Roots Another Form of Root Pruning

Q. I read about air pruning the roots of potted plants using either fabric pots or drilling holes in pots and lining with landscape fabric.  Supposedly, air pruning keeps the roots in "check" so that they do not outgrow the pot.  The idea sounds logical, but with our extreme heat and hot winds, could this work in Vegas?

A. Air pruning is allowing the roots of plants are exposed to the air and die. It is normally used in greenhouse production with potted plants. It can be used for plants growing in containers as well. It is popular where other types of root pruning may not be practical.

            If plants grown in containers are allowed to rest on soil or gravel, the roots of these plants can grow out of the holes on the bottom or sides of the container and into the wet soil beneath it. Once the roots leave the container and grow into the soil, the tops of these plants typically have big growth spurts.

            In the past, if these pots or containers were given a quarter turn twist, this would sever young roots and prevent them from getting anchored in the soil beneath them. This is an older method of root pruning.

            Another older form of root pruning was using chemicals such as copper sulfate applied to the surface of the soil or gravel just under the pots or containers. The concentration of copper would kill the roots of plants growing into it but would hurt the tops of the plant.

            Air pruning is another form of root pruning where the bottoms of containers are pots are suspended in open-air. Roots exposed to the open-air will die without moisture. As roots leave the container through drainage holes, the roots die and become “root pruned” by the air.

            This would work in our climate as well. However, in our hot desert climate I worry a bit about pots or containers left in full sunlight. The soils in these containers can heat up quickly and the roots “roasted” on the side of the container facing the sun.

            If pots or containers that you are using for root pruning are in full sun make sure they are white or shiny and reflect as much sun as possible. It would be best if they were shaded. Water the plants in the containers just before the heat of the day.

Canary Island Date Palm Dying May Be Disease

Q. I had a mature canary palm in my back yard for about 10 years. This summer it became infected and died. I have a monthly service with a landscaping company and, despite their efforts, was to no avail. Do you suggest I plant another one or buy a different type of palm? It was in the center of our yard and served as a focal point to our landscaping.

A. Depending on why the palm became sick will determine if you can replant in the same hole. In California this palm is susceptible to a disease called Fusarium wilt which can contaminate the soil in the planting hole and prevent you from planting a new one in that spot. To my knowledge, this disease has not been reported on this palm in southern Nevada but your description fits.

            Older or lower leaves sometimes die before the newest leaves in the center begin to turn brown and die. In some cases leaves or fronds in the center of the canopy may die while the lower leaves appear healthy. And in even other cases, leaves on one side of the palm may brown while the other side remains green.

            Often, leaf fronds turn yellow before dying so it’s possible to confuse it with the chlorosis such as iron chlorosis or other micronutrients like manganese. The yellowing leaves may be confused with over watering symptoms. Infected palms frequently die in a couple of months or in some more rare cases die a slow death over several seasons.

            This disease can be spread on pruning tools such as chainsaws so it is important that these tools be sanitized properly between trees and between cuts if the tree is suspected of having this disease.

            Another point of entry for this disease is through the roots. If soils around this palm tree are kept excessively wet by watering daily or the soil does not drain very well, this could increase the chances of this disease.

            This disease can sit in the soil and remain active for 20 years or more so I would not recommend planting another Canary island date palm in that same hole. You would select plants that are more tolerant to this disease when planting in this area.

            You should also amend the soil for better drainage and make sure the planting hole drains properly before putting another plant in the same or near the same hole.

Here is a picture of what this disease may look like in Canary Island Date Palm

Here is some information from the University of California regarding this disease in Canary Island Date Palms

http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74148.html

FUSARIUM WILT

The fungus Fusarium oxysporum f. sp. canariensis causes Fusarium wilt, a lethal, vascular disease of Canary Island date palms (Phoenix canariensis). There are different forms of this fungus, and they typically are host-species specific. The form referred to as forma specialis canariensis causes disease only on Canary Island date palms. Other forms of this fungus cause wilts on other species in other parts of the world.

Identification and Damage

Symptoms usually appear in older or lower leaves before moving toward the center or newest leaves, although occasionally this fungus will affect mid-canopy leaves first. Leaves turn yellow then brown but remain hanging on the palm. Initially symptoms might affect the leaflets or pinnae on only one side of the leaf. Pinnae on the other side remain green, although they eventually also will turn brown and die. This pattern was once thought to be diagnostic for Fusarium wilt, but other diseases such as pink rot also can cause one-sided death of leaves. Pinnae death typically occurs first at the base then moves progressively toward the leaf tip, although this pattern sometimes is reversed.

Extensive discoloration along the petiole, the stalk connecting the leaf base to the leaf blade, is another common symptom of Fusarium wilt. External streaking is brown to black while internal, or vascular, discoloration is reddish brown to pinkish. Although incompletely understood, this pinkish discoloration might be a good diagnostic symptom of the disease.

Infected palms can die within a few months after symptoms appear, or they can linger for several years. Because wilt diseases decrease the ability of the host to take up water, palms with Fusarium wilt in cooler, more humid environments, such as near the coast, might show reduced disease severity and survive for many years. Infected palms in hotter, drier interior climates might show severe symptoms and die rapidly.

Because Fusarium wilt stresses palms, the opportunistic and mostly secondary disease pink rot frequently is present and can obscure or mask symptoms and hasten death. In fact, pink rot might kill a palm before Fusarium wilt runs its course.

In the landscape Fusarium wilt spreads frequently on pruning tools, especially chain saws. The pathogen enters cut petioles and, in extreme cases, the cut and exposed vascular tissue of severely pruned or skinned trunks. The pathogen can spread indirectly during pruning, because contaminated sawdust can drift as far as 100 feet.

The pathogen also can spread by entering the palm through its roots. Canary Island date palms tend to form a dense, extensive network of above-ground roots called pneumatophores, especially under excessively damp or wet conditions, which may facilitate pathogen entry.

Fusarium wilt can spread if people dispose of diseased palms or their seeds using a municipal yard-waste program that recycles debris into mulch. The pathogen can survive in the soil for at least 25 years.

Management

Because no cure exists for Fusarium wilt and it is nearly 100 percent fatal, prevention and exclusion are critical to disease management. Obtain palms from a reliable source and avoid poorly drained soils and excessive irrigation that can increase the formation of above-ground roots. Keep the area around the base of the trunk free of plants, because they can damage above-ground roots, and avoid using municipal-yard waste as mulch on Canary Island date palms.

Also avoid or minimize pruning if possible. Frequently pruned palms are more likely to suffer from Fusarium wilt than those in an unmaintained setting. If you must prune, thoroughly clean all tools by vigorously brushing them to remove sawdust and other particles. Disinfect the equipment for 10 minutes in a 1:3 pine oil to water solution, or heat saw blades for at least 10 seconds per side with a handheld butane torch. Use manual pruning saws rather than chain saws whenever possible, because the latter are difficult if not impossible to clean and disinfect adequately. If you have extremely valuable palms, consider using a new saw for each tree, which you either could discard after one use or dedicate for future use on that one palm only. Avoid pruning palms in windy weather to minimize the spread of infected sawdust.

Because a Canary Island date palm with Fusarium wilt eventually will die, it is prudent to remove it as soon as feasible. To avoid spreading the pathogen, excavate the root ball and use a crane to remove the palm with its crown of leaves, trunk, and root ball still attached. Use plastic or wooden barriers to contain any cutting, grinding, digging, or other operations that can spread diseased plant parts. After bagging all debris, prepare removed palms for incineration or removal to a landfill; do not use a waste recycling program.

It is unwise to replant another Canary Island date palm at the same location where a diseased palm once grew, because remnants of infected roots can remain in the soil and transfer the pathogen to the newly planted palm. Removing the soil might not prevent the spread of disease either, because just one small piece of infected root is all that is necessary to infect a newly planted palm. Avoid replanting with any palm species, because host range susceptibility to this disease has not been fully established.

If you must plant a replacement palm, some species to consider include Mexican blue palm, San Jose hesper palm, Guadalupe palm, pindo palm (Butia capitata), queen palm (Syagrus romanzoffiana), and Mexican fan palm. If you want the Phoenix or date palm “look,” consider staminate (male) plants of the date palm (Phoenix dactylifera), because they are more robust than the pistillate (female) fruit-bearing plants and more closely imitate the larger, robust habit of Canary Island date palms.

What Is an Amended Soil?

Q. You recommended that to grow a persimmon tree in our area, the soil needs to be amended. What is amended soil? Do you a technique you recommend to amend the Las Vegas soil?

A. Soil is amended by mixing it with something that improves the existing soil in some way. There are a number of amendments available but I prefer compost for most garden soils and fruit trees.

            Compost improves the desert soil chemistry, soil structure and its biological activity. Compost opens the soil improving drainage and aeration as well. Our desert soils have very tiny pore spaces between soil minerals. Larger pore spaces are important for roots to stay healthy. Roots need about an equal mixture of water and air between soil particles.

Desert soils have very small amounts of organic amendments in them making them very poor at growing vegetables

            Compost improves soil chemistry by reducing the alkalinity of desert soils and helps chemicals required by the plant to become more available to them.

Compost added to a vegetable growing area. The compost will be mixed with the desert soil and raised beds will be shaped from this amended soil

            I recommend that existing desert soil be removed from a future planting hole and this soil mixed about half and half with compost. Once the large rocks are removed, this amended soil is used to fill the spaces around plant roots when planting.

            Organic soil amendments like compost disappear in the soil over time so they must be replenished. Replenish soil amendments by adding a 1 inch layer of compost to the top of the soil every year. Compost slowly “dissolves” back into the soil, keeping the soil amended.

Woody Warts on Oleander Is Gall

Q. I live 8 miles northeast of Mesquite NV in Littlefield Arizona. I'm sending two pictures of some scaly growth like woody galls on the tips of my Oleander branches. There is also galling taking place on the branches and leaves. My oleanders are the only ones infected. How do I correct this problem? Will it kill the plants? Every plant is infected, about 300.

Oleander gall from the reader

A. This is called oleander gall in Arizona, oleander knot in California and Texas calls it bacterial gall. I wouldn't use any chemicals. Prune it out and sterilize pruners after cutting because it will spread on pruning instruments. If you use bleach as a disinfectant make sure you oil any steel that it comes in contact with.

This particular disease is spread from plant to plant on pruning tools. It can also be spread during wet, windy weather just after pruning. Avoid irrigating oleander with overhead sprinklers. Drip irrigation or bubblers would be a better choice.

            Even though it’s a bacterial disease, you can use chemicals such as copper fungicides to help reduce the infection but they are not necessary. Most of this can be handled with proper pruning.

            Make sure all pruning equipment is sanitized. In this particular case, you should sanitize pruning tools between cuts and between plants to keep from spreading this disease on pruning tools.

            I would use a 10% bleach solution applied to pruning blades or pruning saw with a spray bottle. Make sure you oil all pruning tools and blades when finished or the bleach will rust them.

            Plants that have a few of these galls present can be pruned and the galls removed. Prune 6 to 10 inches below the galls and sanitize your pruning equipment before each new cut.

            If a plant is severely infested with oleander gall, I would cut it to the ground this winter and let it regrow from the base.

            Fertilize the plants with a high nitrogen and high phosphorus fertilizer in January and give them a large volume of water each time you irrigate.

http://cals.arizona.edu/maricopa/garden/html/t-tips/diseases/olndr-gl.htm

Oleander Galls in the Low Desert

PLANTS MOST SUSCEPTIBLE: Oleander

SYMPTOMS:

Rough, fissured growths on twigs, branches, leaves, flowers, and seedpods, often appearing in chains. Galls start out as small bumps and grow into wart-like growths generally between 1/2 to 1 inch in diameter. Large galls may actually be several small galls that have grown together.

CAUSES:

These galls are the result of growth of the bacteria Pseudomonas syringae inside the plant. The bacteria can enter the plant through wounds caused by pruning, frost damage or other injury or through natural openings in the leaf, blossom and stem. Water can carry the bacteria from diseased plants to healthy ones in the splash from rain or sprinklers. The bacteria is also moved from infected plants to healthy ones by unsuspecting gardeners on their pruning tools.

MANAGEMENT:

Prevention: Inspect oleanders carefully prior to purchase, do not buy plants that have galls.

Management: Remove the galls by pruning several inches below. Treat each cut with 10% bleach solution. Dip pruning tools in a 10% bleach solution between EACH cut to reduce the possibility of spreading the bacteria. Bag and discard cuttings. Do not compost diseased plant material.

Prune during the dry seasons to avoid infection of wounds. Avoid sprinkler irrigation while pruning wounds are fresh.

Severe infection of large shrubs is difficult to control by selective pruning. Even if you cut down the entire shrub, the new succulent growth will still be extremely susceptible to infection. In certain situations, removal of the diseased plant and replanting may be the best method of control.

http://www.ipm.ucdavis.edu/PMG/GARDEN/PLANTS/DISEASES/bacterialgall.html

Oleander knot—Pseudomonas savastanoi pv. nerii

Pseudomonas savastanoi pv. nerii causes galls or knots on oleander stems, bark, and leaves. Twigs and branches can die back, but the overall plant health is usually not seriously threatened. Gall bacteria reproduce in fissured or galled bark and are spread by contaminated water, implements, or hands. Healthy tissue is infected through fresh wounds during wet weather. Susceptible wounds include frost cracks and any leaf scars on branches.

Solutions

Avoid overhead watering. Prune out and dispose of infected tissue during the dry season. To prevent spreading pathogens on infected tools, clean tools of debris after each use and thoroughly spray them with disinfectant or soak them in disinfectant for one or more minutes. Tools can be sterilized using a commercial disinfectant as directed on the product label. Homeowners on their private property can use household bleach or disinfectant cleaners diluted 1 part disinfectant to 10 parts water.

http://aggie-horticulture.tamu.edu/galveston/Gardening-Handbook/PDF-files/GH-038--bacterial-gall-on-oleander.pdf

Bacterial gall

Disease Pathogen Name: Pseudomonas syringae pv. savastanoi

Pathogen Type: Bacterium

Period of Primary Occurrence: after spring rains & cool weather

• The bacterium must have a wound site to enter the plant, and cold weather injury in early

spring after a rain is a common circumstance under which infection takes place

• Most common after a cool wet spring

Description / Symptoms

• The bacterium is systemic in the plant, and causes galls to form on flowers and stems

• Leaves also become galled

• Twigs and branches can die back, but overall plant health is usually not seriously

threatened

• Gall bacteria reproduce in fissured or galled bark and are spread by contaminated water,

implements, or hands

• Healthy tissue is infected through fresh wounds during wet weather

Best Management Practices (BMP)

NON-CHEMICAL CONTROL

• Bacterial gall normally will not kill the plant

• Infected plant parts can be pruned, but care should be taken not to disseminate the

bacterium on pruning tools

• Prune infected tissue well below the infection site, at least a foot if possible, and disinfect

pruners between cuts by dipping them in a 10% bleach solution (common household

bleach at 1:10 dilution) for a few seconds

• Be sure to rinse the bleach off tools when you are finished and apply an oil lubricant to

avoid corrosion of the metal

CHEMICAL CONTROL

• Severe infections can be controlled by applying Bordeaux mixture or a copper fungicide

beginning in the fall and periodically spraying through the spring as new growth

appears

• Bordeaux mixture (originated in France) as a 4-4-50 ratio. For a small amount of mixture,

the ingredients are:

- 3 1/3 tablespoons of copper sulfate and 3 tablespoons of hydrated lime, mixed in

one gallon of water

- The mixture will turn the tree blue; however, the color will eventually disappear.

Caution must be taken NOT to store a mixture of Bordeaux

- The ingredients must be kept separate and custom-mixed as a fresh spray

Fall Planting Guide and Constructing Raised Beds

Q. My husband and I appreciate your input in guiding us to our next planting season. I know it might be a little too late but I am open for ideas to continue our gardening on a raised bed. This summer we had a great time growing Kale, red and green chard and jalapeno peppers and basil.

 Any suggestions will be greatly appreciated.

A. I will give you my version of raised beds, the kind we built at the University Orchard for growing vegetable crops. I wrote some instructions for building these types of raised beds for Viragrow, Inc. as a consultant. I attached to these instructions so that you could follow them.

Raised bed made without sidewalls

The first part tells you what to plant in the fall and winter months and whether you can start them from seed (s) or transplants (T). The second part tells you how to construct raised beds without building sidewalls but just using the natural slope of the soil to retain their raised shape. 

Raised bed made from wood

Some people like to build sidewalls from wood, brick or cement block to surround these raised beds. This is entirely up to you. But once you have constructed raised beds you should not be walking in them unless you are preparing the soil. 

Raised beds should be wide enough so that you can access the entire bad by using either side. Walkways are 18 to 24 inches wide between them and this is where traffic should be kept. Walking on these beds transfers weed seeds, diseases and compacts the soil making the soil more difficult to grow vegetables. I hope this helps.

Depth of Rock or Wood Mulch Depends on the Size of Mulch

Q. I have been replacing gravel with wood mulch and I have to put the gravel someplace. What thickness of gravel can I place around the plants, none at the trunk, without causing damage?  Also, what is the maximum amount of wood mulch can be place around plants without being detrimental to the plant?

A. The depth of rock mulch depends on the size of the rock; the larger the rock used the deeper rock mulch can be applied. Roots need to “breathe” so there must be an exchange of gases between the roots and the air. This happens through the pore spaces in the soil.

Rock of a larger size can be used as mulch and applied more deeply than smaller rock

            Generally speaking, rock mulch is applied somewhere between 2 to 4 inches deep. If this rock mulch contains “minus” material (e.g., 1/2 inch minus, ¼ inch minus) then apply 2 to 3 inches. If the rock mulch does not contain minus material then apply it 4 inches or more.

            Course mulch without minus material can be applied right up to the trunk. Rock mulch with minus material should not.

            Most information out there tells us not to apply more than 3 to 4 inches of wood chip mulch around trees and shrubs. Where this recommended depth came from I don’t know but it is repeated over and over.

            I have no problems applying 6 inches of wood chip mulch or more around trees and shrubs provided this mulch is kept away from the trunk of the plant a distance of 12 inches during its first four or five years of growth. 

Reattach Broken Limbs Quickly

Q. My newly planted pluot tree produced one fruit this past season. I guess I pulled too hard and the branch where it was attached split. I taped the split back together with electrical tape. When can I remove it?

A. Limbs that have split will never grow back together unless you reattach the broken limbs within a few minutes after the split occurs. Once the crack or split dries, they will never “fuse” back together.

            Plants grow around wounds and surround new growth by burying this damage in older wood. If the split occurs in a strategic location that supports the weight of future limbs and fruit, it will probably never be strong enough to support increasing weight in future years.

Broken peach tree limbs due to the weight of a fruit load

            I don't know how rapidly you got the tape around the wound but if this happens again you must reattach the split tightly in a matter of a few minutes. I like to use the expandable green nursery tape that you can purchase from most nurseries are garden centers.

            I am guessing the split did not grow back together, is still there and the limb no longer structurally strong enough to support fruit or the weight of new branches growing from it. Remove the broken branch with the pruning shears and reshape the tree for future growth.

Replant Ratty looking Photinia This Fall

Q. My red tip Photinia took a beating this first summer after planting. Should I wait until its cooler and cut the down to force new growth or replace them?

A. I would wait until the beginning of October, gently lift them out of the ground, wash the soil away from the root ball, add compost to the soil used for backfilling around the roots and replant them. After replanting them, I would then cut them back to about 6 inches above the soil.

            Photinia can handle our hot desert climate with no problems provided the soil is amended with good quality compost at the time of planting. It also does not like rock mulch. Planted in rock mulch I will give it five years before it starts to look ratty.

            The problem is I don’t know how your plants were planted. Judging from the pictures you sent, the soil surrounding them does not look like it has enough amendment added or the amendment was not very good. Also, I’m not sure if you planted them at the correct depth.

            You can use the existing native soil when planting them. But you must amend this soil with about 50% good quality compost when planting them.

            The rootball taken out of the container should not be placed too deep. It should be the same level as the soil surrounding it. It is very important to thoroughly soak the soil surrounding the plant after planting several times to settle the soil.

            When digging the hole for the plant, it does not have to be deep. Dig it deep enough only to accommodate the rootball. It is far more important to dig that hole wide and amend the soil in that planting hole surrounding the roots.

            Fertilize them once a year in January and use a good quality iron chelate along with your fertilizer.

How to Transplant Joshua Tree

Q. When is the best time to transplant a Joshua tree?

A. The best time is in mid to late spring but could be done in summer. The worst times are fall and early winter months. Stay away from these time periods for planting Joshua.

Joshua tree rootball

            The biggest mistakes made on planting Joshua is watering too often. Joshua's are not the easiest plants to transplant mostly because the roots taken when harvested from the Desert are not very extensive.

            Start with a smaller plant and stake it to keep the roots from moving. Plant them the same depth as they were when they were harvested.

            Amend the existing soil with about 25% compost at the time of planting. They will benefit from improved soils at the time of planting. Water at the time of planting thoroughly and then hold off for at least three weeks before watering again.

            Water no more than about every three weeks in summer. Less often in cooler and colder weather.

Recipe for Prickly Pear Fruit (Tuna) Jam

Q. I remember that you had posted an article about making jelly/jam from the flower pods of the Indian Cactus. I have several of these cacti and would like to try making the jelly/jam. Would you please repost or send me the procedure for doing this.

A. There is a big variation in the quality of fruits produced by cactus. There are selections of Indian Fig cactus or Opuntia or Nopales that produce better quality fruit, better taste, than others. 

One way you can measure this is by bird damage. If the birds are not annihilating your cactus fruit then my guess will be the fruit is not that good. Typically, birds ravage the good ones and seldom touch the ones that are not so good. 

Bird damage to the nopal fruit (tunas) indicating they are a sweet fruit good for eating and preserving.

Sugar content of these fruits or tunas as Mexicans call them can get to a similar range as table grapes or apples. I have attached the book on it that I produced and you can download it. I will also post it on my blog for people to download.

Translated from Spanish so the English is a little awkward.

From M.V. Fernandez and J.C. Morales

University of Sonora-Hermosillo

Jam of Prickly Pear

Ingredients:

2.2 lbs (1kg) of prickly pear fruit (tunas) peeled (15 tunas approximately)

3 1/2 cups of sugar (840 g)

1 tablespoon of pectin

1 tablespoon of lemon juice

Cut prickly pears in pieces and blend only half of them. Keep the rest. (Because the seeds are very hard, I pureed all the fruit and strained the pulp.) Put blended fruit into a pan and cook over medium heat; as soon as it begins to boil, add the pectin, the sugar and the lemon juice. Keep stirring the mixture constantly with the spoon. Once it starts the first boil, while stirring, add the remaining fruit if you desire. Remove the jam from the heat when it acquires a thick consistency and when shaking pan the bottom can be seen (more or less after one hour). Put the hot jam into the sterilized container immediately. (Our test jam cooked more quickly.  Be careful not to overcook.)

Packaging and Preservation for safety

On a dry cloth, place the sterilized bottles or jars. Pour in the still hot jam, with help of a spoon, leaving a minimum space of a half inch between the mouth of the bottle and the jam. Allow some steam to escape and close it tightly to form vacuum. Let cool to room temperature and place a label in the bottle with the product name and date.

Jam will be ready for its consumption in 12 hours after it was prepared. This jam will keep for a year in a fresh and dry place. Once opened, the jam must be refrigerated and consumed in a month.

Alternative ingredients:

The lemon juice can be replaced by ¼ tablespoon of ascorbic acid or one crushed Vitamin C tablet of 500mg.

Recommendations:

To keep the jam in good condition, sterilize the bottles and the cover in the following way: wash them thorougly, retire the labels and put them to boil (with enough water so they keep cover all time) during 15 minutes counted from the first fervor or boiling. Taking off by far care, with the aid of clamps or a knife in a hand and a dry rag in the other; place the bottle and the cover on a totally dry and clean cloth (if no, the bottle can be broken). Do not touch the jam with the hands when it is still hot, since it can cause a serious burn.

To take a small taste of the jam before complete the heat treatment, take a few with a spoon, drain it in a plate, and leave it to cool completely.

Preserving Large Trees When Converting to Desert Landscaping

Q. We are planning on removing our lawn and changing over to desert landscaping but after reading your blog I am wondering how the old, large Modesto Ash trees will fare from this change? Do you think it would be an issue? I tried to find out about their root system, it seems like it is shallow, but won't that be an issue as the roots will be damaged and then covered with hot rocks?

See this posting on my blog:

http://xtremehorticulture.blogspot.com/2015/08/converting-to-desert-landscapes-can.html

Large tree suffering die back due to drought after conversion to desert landscaping

A. I am not telling you not to convert to desert landscaping but be cognizant that established trees can get hurt in the process and many landscapers do not know how to convert from lawns to desert landscaping with existing large trees. 

If you have large trees in an established landscape you have some options. 

1. Leave the lawn surrounding the big trees and remove lawn where there are no big trees. 

2. Remove lawn and spiral in-line drip tubing around the existing trees out to a distance of their drip line (spread). However, if you do this you should put this drip tubing on a separate valve and run it longer and less often than drip going to other plants. 

3. Put LOTS of plants beneath these large trees and drip irrigate them to assist the existing trees with enough water. This is above and beyond having emitters for the large trees, too. 

4. Use a lawn irrigation valve to feed bubblers to existing trees and form a basin around the trees to capture water from the bubblers. This is called basin/bubbler irrigation and is a form of flood or border irrigation. The basins must be level and flat and be three to four inches thick.

HOA Replacement Trees for Privets, Ash and Sycamore

Q. I am on our landscape committee for a Henderson, Nevada, HOA. Needing professional advice, I thought of you immediately, as a longtime resident I read your weekly column and read your blog.  This fall we are going to remove many dead and diseases trees in our small community. Mostly privets that thru the years have died after we converted to desert landscape from grass. Others are mainly Russell Ashes that are diseased and or have dead limbs and with pruning look terrible, lopsided, etc. I am without hope that with the pruning done they will ever pull out of it. The various landscapers thru the years used the ashes as replacements and as I have read in your column are no longer considered a good choice. Most of all our yards in our small community face either East or West. We have been advised to replace the trees with Fruitless Olives or Living Oak. All yards are small and have rock mulch. As many other communities we are cash poor and need to make a wise decision, because it will be expensive. We will be replacing approximately 25-30 trees. The other mature 15 yr. old trees in our landscape are sycamore and for the most part doing well, along with a few other Desert Willows,etc.  We are looking for evergreen, shade trees if possible.

Thank

you so much,

I forwarded this email to a certified horticulturist working here in southern Nevada. She has worked with plant selection for a number of years and enjoys answering this type of question.I do want to mention that sycamores are a poor choice as a landscape tree for single-story or even two-story residences. They just get too tall, they consume a lot of water and require a lot of maintenance because they are out of their climate zone. In my opinion they should not be planted in hot desert climates and desert soils. They are a larger scale tree and require big properties to look good. They do well in arid climates provided there is enough water for them. Certainly they should not be planted in large quantities.

Bob Morris

Sycamore near south facing wall with heat damage to the leaves facing the wall

A. Bob Morris forwarded your email to me.  I am Andrea Meckley, a certified horticulturist working here in the Las Vegas area since 1992.  I understand your situation with the privet trees doing poorly.  Since you are going through the expense of replacement I realize you want to make good choices.  Below are a few thoughts:

1. Fruitless Olives:

                  Pros:  evergreen,  little leave drop  

                 Cons:  slow grower,  sometimes they will fruit even though they are not supposed to.  If this happens you can apply a solution to stop them from fruiting if it concerns you.

2.  Southern Live Oak:  

                 Pros:   evergreen

                 Cons:  slow grower, debris from leaves and acorns

Between the two above I would choose the Olive.  

Since you have existing Sycamore and Desert Willow trees that are deciduous, I would also consider the following medium size evergreen and semi-evergreen trees:  Xylosma tree (Xylosma congestum), Holly Oak (Quertcus ilex), Blue Palo Verde (Parkinsonia florida) , Desert Museum Palo Verde (Parkinsonia 'Desert Museum'), Bay Laurel standard trunk tree (Laurus nobilis), and Shoestring Acacia (Acacia stenophylla) which may be a little messy.  One good source for good pictures and more information can be seen at snwa.com under 'landscapes' and then under 'plant search'.  Please contact me if you wish to discuss further.

Hope this helps. 

Andrea Meckley, CH

imn2plants@aol.com 

Trees for Privacy and Hummingbirds

Q. Putting landscape in backyard of new home in a couple of weeks what type of trees do you suggest that will give me privacy and not shed all leaves in the fall also trees and shrubs that attract hummingbirds.

I am not fond of making tree recommendations so I am ccing this to Andrea who loves to do that kind of thing. Good luck!

Bob Morris

A. I am Andrea Meckley, a certified horticulturist working her in the Las Vegas Valley in the green industry since 1992.   Attached is a Hummingbird Plant list.  Also is attached the middle pages of a publication called Trees for Tomorrow.  

Without knowing more details on the tree you want, I suggest you check it out.  I could not scan the whole list of large trees so if you need that info go to www.lasvegasnevada.gov/files/trees.pdf  That website address will also give you pics and more info on each tree.  

I assume you want a small to medium size tree.  Since you want a tree with leaves all year, start with trees labeled 'evergreen' in the 'tree type' column.  Narrow the choices depending on flowers (some debris), water use, thorns, etc. according to chart.  Also visiting demonstration gardens is a good reference tool to use in choosing plants.  We have the Springs Preserve and Master Gardner Demonstration gardens in Las Vegas and Acacia Park in Henderson.

Please Define Deep Watering

Q. Please define "deep watering." In particular, how would you describe "deep watering" a pomegranate bush with a 3" to 4" trunk?

A. Good question. I throw these terms around and I assume people know them or understand them when they don't.

            Deep watering is talking about applying enough water in one irrigation so that the entire root system becomes wet. When deep watering it is also accompanied by less frequent irrigations. This means giving the soil and roots a chance to dry somewhat before the next irrigation.

            There are two ways to water. One way is to give a small amount very often, perhaps daily or twice a day.

            The other way is to apply a large amount and then wait a long time before you give it more. The second way is preferable to the first way for plants that are deep-rooted. Deep-rooted plants are larger, woody plants such as all trees, all large and medium-sized shrubs, all woody vines, and all woody groundcovers.

            Water these types of plants deeply by applying enough water so that the applied water drains to a depth of 18 to 36 inches. The water is then shut off until that soil begins drying. Technically, the plant is not watered again until about half of the water in the soil has been used.

            When half the water is gone, water is applied again until it reaches the same depth as before. This is a continual cycle with the number of days between irrigations decreasing as it gets harder and increasing as it gets colder.

            Deep watering normally applies to woody plants but not to lawns, flowerbeds, vegetable beds and small fruits like strawberries. These are shallow rooted plants and their applied irrigation water is shallow, not deep.

 Deep watering a pomegranate that has a 1 inch diameter trunk is really no different than deep watering a pomegranate with a 3 to 4 inch trunk. Water is applied to the same depth with both of these trees. 

The difference between them is where the water is applied and the amount. In the case of a pomegranate with a 1 inch diameter trunk, we might use only two drip emitters. Two drip emitters might deliver enough water to the soil under the canopy while it is small. 

However, when the pomegranate gets to 3 to 4 inches in diameter, more emitters are needed because the larger tree requires more water. These emitters are spaced far enough apart so that the water is applied over a greater area under the canopy of the tree. The number of minutes on the irrigation clock may not of changed but the number of emitters has so the larger tree now gets more water.

Nutgrass or Nutsedge Difficult to Kill with Chemicals

Q. I have tried digging this weed up but it comes back. I have tried both Roundup and Spectracide according to the package directions, and even painting it on the foliage full strength.

Although it starts out pretty small, if I miss pulling one up, they get quite large. Any assistance in getting rid of this plant is greatly appreciated.

Judging from the roots which actually look like a rhizome I believe this is nutgrass.

A. Judging from the pictures you sent this is one of the nutgrasses or nutsedge. The roots sure look like it to me. To be sure if it is one of the sedges and not a grass, cut the top of the weed off at its stem just below the leaves. Roll the stem between your fingers and see if the stem is triangular rather than round.

            Sedges have triangular stems in cross section. Rolling the stem between your thumb and first finger you should “feel” the triangular bumps of the stem and the stem should not feel round.

Nutgrass with nut attache to the rhizome or "root".

            Sedges, like nutgrass, are more difficult to kill than grasses. Nutgrasses have underground “nuts” attached to the “roots” which are really underground stems called rhizomes. These nuts grow into new plants if they are separated from the mother plant or the mother plant is killed.

            This is why pulling, hoeing or using chemical weed killers do not work on this plant. As you have found out, spraying the tops with Roundup or dandelion killer “burn” the tops back but release the growth of the nuts.

Triangular stem of nutgrass in cross section.

            These nuts are usually anywhere from 4 to 8 inches below the soil surface. All you have done is kill the mother plant and the baby plants released from the nuts that pop from the ground grow like they are on Red Bull. Pulling nutgrass from the soil easily separates the nuts from the mother plant with the same result.

            What to do? There are two basic approaches toward getting some control. The first is soil replacement. If it’s a small area, you can dig down 12 to 14 inches deep, remove the soil and replace it with clean soil. You can take the soil and put it in a clear plastic bag in the middle of summer and “cook” it using the sun.

            You can starve out the nuts. If you continue to remove the tops at the soil surface, over and over, before they get more than two or 3 inches tall it is possible to exhaust or starve the nuts so that they die. If you pursue this option you have got to stay on top of it or it will not work

Palm Tree Roots Exposed – No Problem

Q. This is the pics of the palm tree roots. Why are the roots growing above the surface? Is it an issue and can I do anything to correct it? 

A. This is very common among palm trees and nothing to be alarmed about. You can leave them be or if you don't like the look of it then mulch the surface of the soil 5 inches deep with a wood chip mulch. The palms will benefit from that mulch. It's an aesthetic issue and not a palm tree

management issue.