Be Careful of Misdiagnosis of Sooty Canker

Q. Our flowering plums have been infected by what was diagnosed as “sooty canker” disease.

Sooty canker on Apple

They were treated by arborists but the blight continues. Infected limbs were cut until one of the trees needed to be removed entirely. I am advised this blight has become epidemic in Las Vegas Valley. Is there a solution to cure or at least treatment for sooty canker?

A. Be careful on any diagnosis of sooty canker. There are a lot of natural things that can look like it and if you've never seen it before or don't have much experience around it, it can be easily misdiagnosed.

Sooty canker on poplar

Sooty canker disease causes limb dieback and the bark of the dead limb to peel away revealing a black, sooty powder on the wood. When you take your finger and rub against this black powder it will come off on your finger and look just like soot from inside your chimney.

There are other natural black “powders” on limbs which will also rub off on your finger. But sooty canker is jet black on your finger and unmistakable once you see it. I will post a picture of sooty canker on my finger on my blog so you can see what I’m talking about.

Beginning of sooty canker on Mulberry

I disagree, it is not an epidemic in Las Vegas. It attacks a small number of trees every year at about the same rate for the past 30 years. Many trees can become infected but we see it most frequently on Mulberry and Poplar (cottonwood) and occasionally on Ash and Elm.

I don’t remember seeing it on truly desert trees such as Mesquite, Acacia or Palo Verde.

It can be spread easily on pruning equipment if the equipment is not disinfected between cuts and between trees. 

Be very careful when this is diagnosed. If a limb is dead, it is dead and must be removed. We don't want to be removing limbs with the wrong diagnosis.

Control Blight of Tomatoes Now!

Control Blight of Tomatoes Now!: Tomato early blight developing on lower leaves. Leaves first yellow, develop spots, wither die and progress through the plant. Early Bli...

Viragrow Delivers!

Get Rid of Springtails by Mopping Up

Q. I was told by the Nevada Department of Agriculture the tiny insect I found jumping around in my bathroom were springtails. I have read they are very hard to kill which I finding out after I had an exterminator try to get rid of them.

A. Insecticides are not a good choice for controlling springtails. It usually requires several repeat applications of traditional household insecticides and they will return if the source of the problem is not corrected.

What are springtails?

Springtails are tiny jumping insects, about 1/16 inch long, that are found in cooler times of the year where there is standing water. I have seen them here outside in grass that is kept too wet or where there is a water leak.

Because they are such good jumpers they are sometimes confused with leafhoppers outside the home and fleas inside the home. They are neither.

Inside the house they can multiply where the flooring is kept constantly moist. They feed live off of mold and fungi that grow where there is shallow, standing water or very wet soils. If the area is kept dry and cleaned up they will disappear.

Save your money. Don’t apply pesticides. Fix the area so it stays dry and sanitize it.

Prevent Roaches from Mulches Entering the Home

Q. I know you recommend bark mulches around trees to help in water retention. However, there are negatives to consider such as cockroaches, bugs, etc.  I encounter lots of cockroaches in the ground when I have excavated in certain areas of our yard.

Untreated wood chip mulch including pine needles and leaves

A. I encourage the use of wood mulches more than bark mulches. Bark mulches seldom decompose much and add very little value to the soil. They are purely decorative. Wood mulches decompose easily in moist soils and add a lot of value to desert soils.

Benefits of wood chip mulch

You are absolutely right. Insects such as cockroaches are scavengers. Like many insects they like two things; water and a food source. This is why you frequently see tons of them inside irrigation boxes.

They feed on plants and animal life that have died and help in its decomposition. Feeding on dead and animal life helps return organic life back to the soil.

Cockroaches do not discriminate between dead plant or animal life whether it is inside the home or outside the home. They will enter the home if given the opportunity.

Using a foundation spray

Using a foundation spray or pesticide around the perimeter of the home and in valve boxes helps to keep them from entering our home. This is an insecticide spray barrier applied to the outside of the home at soil level and 12 inches above the soil. A good time to make this application is when temperatures begin to cool in the fall.

 It also helps if you keep wood mulches away from the foundation of the home. There is no reason you need to apply wood mulches up to the foundation.

Pruning Fruit Trees in Late Spring

Q. I have added some fruit trees such as Asian pear, peach and apricot to my yard. When is the best time for pruning these trees?

A. The pruning of fruit trees is done for two separate reasons; establishing the architecture or structure of the tree and encourage the production of high quality fruit. There is even a third reason that is not talked about very often and that is helping to keep trees smaller.

Winter pruning establishes the architecture of the tree. The most productive branches are at 45° angles.

Prune at the Time of Planting. When purchasing a tree and its structure needs improvement, you should prune for improved structure immediately after planting and not wait until the end of the growing season.

Prune in Winter Months. With established trees, major improvements to the architecture of an established tree that require a pruning saw or loppers should be done in the winter months. For deciduous fruit trees, it is much easier to see the architecture of the tree when the leaves are gone. Smaller changes in its structure requiring a hand pruners could be done anytime.

Summer Pruning. I encourage summer pruning during the month of April and early May in our climate. Summer pruning focuses on removing aggressive vertical growth that has grown since spring. Sometimes we refer to this growth as “suckers” or “watersprouts”.

Strong vertical growth can be removed very early in the season by pulling downward. This is called summer pruning and helps to reduce interior shading of the tree and improves fruit quality and production. It also helps to dwarf a tree by robbing it of its new growth.

Summer pruning is used to reduce the interior shading of fruit trees which decreases production and helps keep the size of fruit trees smaller. It is also used to take away the future growth potential of a tree. When a tree is pushing new growth it is making an investment in the future. The tree is using stored food reserves for pushing new growth. That tree will recover the food reserves it used and more after its new growth has matured.

Strong vertical growth is seldom fruitful in the short run. Strong vertical growth is used by the tree to gain height. This type of growth should be removed and is easy to do. Pulling downward on immature watersprouts will remove them cleanly and efficiently without using a pruning shears. If you wait too long this growth can no longer be removed by pulling. It must be cut off. This leaves stubs that will sprout in the future.

Raggedy Roses Probably Damage from Thrips

Q. My yellow roses were beautiful the first time they bloomed before Easter. However, the flowers aren’t pretty any more after they open. The flower looks burned on the edges of the petals. I haven't seen bugs on the flowers. Otherwise the plant looks healthy to me.

A. Your roses, from the sound of it, are probably infested with Western flower thrips. These are very small insects that are nearly impossible to see unless you use a magnifying glass and inspect the flowers very closely. They are also difficult to control.

Posting in pictures by Colorado MasterGardeners
Thrips damage on lots of things in Canada

Thrips are poor fliers and so stay close to the plants they feed upon. They have mouthparts that shred tender plant parts such as flower petals and flower buds before or after they open. The flower petals appear damaged and with streaks of brown.

Soap and water sprays are somewhat effective but the best to spray for controlling this insect contains Spinosad.

Dormant sprays of horticultural oil during the winter and applied before the plants start growing will also help. I would alternate sprays between an insecticidal soap such as Safer's and Spinosad sprays until you get some control.

How to Grow Moringa in the Las Vegas Valley

Q. I planted a Moringa tree for its health benefits. I understand it is native to the tropics. Can you tell me how to grow it in this climate?

A. You know that Moringa will be killed back to the ground every time we have a hard freeze. For this reason, we have to manage it similar to bougainvillea. Moringa grows on its own roots so we don’t have to worry about suckers developing from a rootstock like we do with most tender citrus.

Moringa is one of those plants touted for its health benefits. It is native to tropical and subtropical South Asia and has spread to Africa, South East Asia and more recently Latin America where the leaves and pods are used in cooking. Most recently it has been labeled a “superfood” by the media.

Moringa is also called the horseradish tree, drumstick tree or malungay. It will grow here but it has to be managed differently than in the tropics. Establishment of the tree by cuttings or trunk cuttings is quite common in the tropics. Establishment in our desert soils is similar to any fruit tree by using compost to amend the soil during the time of planting. This is a tree I would mulch with wood chips, not rock mulch.

Marine got can be started from seed very easily. Start them the same way you would start tomato seeds or any other tropical seed. They require warmth, above 70° F moisture and good drainage. Start them as early in the season as possible so that you get enough growth on them before you put them out.

Moringa or Mulungay in the Philippines this tropical tree easily suckers when cut back. Moca Farmily Farm in the Philippines.

Growth rates of this tree are extremely rapid and you can expect 6 or more feet of growth during the first year if it’s given enough water. This is a large tree in the wild and it will want to have one central trunk.

You should discourage this central trunk by cutting it close to the ground after it gets about 2 to 3 feet tall. This pruning cut will encourage suckering from the base of the tree which is what you want. You should probably grow it as a shrub, not a tree in our climate.

Let it get damaged in the first light freeze of the winter. After the freeze has passed, cut the plant to the ground and protect it during very cold weather.

You can do this by throwing a blanket over it and preventing the blanket from blowing away during high winds. Remove the blanket during warm daytime temperatures. Fertilize it with your favorite high nitrogen fertilizer that promotes leaf and stem growth. 

How to Move a Joshua Tree

Q. I am lucky to have a Joshua tree that is about 3ft tall and I am thinking about moving it now that it has been five or six years in the ground. Am I going to be successful in moving it or do you think I will kill it?

Joshua tree that was planted and still small enough
 to move without much difficulty.

A. Joshua trees are difficult to move from the wild but much easier when it has been planted once and watered with drip irrigation. It should move okay.

Your major precautions are to make sure its new home drains water easily and not to overwater it after planting. I would avoid moving it when it is hot but you could move it now during the spring or fall months.

Dig the hole where it will be planted ahead of time. Fill this hole with water and make sure it drains in a few hours. Amend the soil taken from the hole with about 25% compost and use it for backfilling the hole after planting.

Add a handful or two of a high phosphorus fertilizer to this soil mix to encourage rooting. It will be important to stake the tree the first season after planting to keep the roots from moving during establishment.

Take as much of the root system as possible when you move it to its new home. There will be far less shock to the plant and better establishment if the roots are disturbed as little as possible.

Moving a much larger Joshua tree with very little root system.

Most of the roots will be close to the drip emitters or source of water and within about 12 inches of
the soil surface. When you move it, take as much of the soil around the roots as possible and plant it with this “root ball”.

Make a mental note of the north side of the tree. Orient it the same direction as it was previously. Stake it after planting for one growing season.

Do not water too often. You can overwater it by giving it more water in a single watering but do not give it water more than every three weeks.

Late Application of Iron Fails to Cure Yellowing

Kerex iron application made to the soil after growth has already begun will result in yellow leaves on the older leaves while the new leaves coming out after the application will be green.

Q. I have a Burgundy plum tree that is 3 years old. The leaves became yellow in March so I applied Kerex iron to the soil when I first noticed the problem. Now the new leaves do not show any yellow in them but older leaves are still yellow so I do not think it is an iron problem.

A. Iron does not move once inside the plant. It is still an iron issue. You said the NEW leaves do not show any yellow. That means your KeRex application in March worked for the leaves which grew after your application.

Iron does not move around inside the tree once the plant takes it up, it only goes into the new growth after the application is made.We say that iron is immobile once inside the plant. It is not like nitrogen which can move from older leaves to newer leaves. Iron cannot do this. Iron can only be transported into new growth. Growth before the application will still stay yellow.

Correcting the problem. The only way to correct yellow of older leaves is with iron spray applied to the leaves. This is why SOIL applications of iron are so important to make in January before growth occurs.

An example of an iron product that can be used for foliar applications, or sprayed on the leaves. Spraying the leaves with an iron solution is the only way to correct yellowing once it is already started. Make sure you use a wetting agent mixed with the iron spray.

EZ Wet is one example of a high quality wetting agent that does not contain
any personal care products and made entirely from yucca extract.

It is not too hot too late to spray iron on the leaves. It may take four or five sprays a couple of days apart to get all the yellow leaves completely green.

Any iron product, labeled as a spray applied to the foliage of fruit trees will work. However, I would strongly suggest that any water mixed with this iron fertilizer should be distilled water so that the pH is close to neutral (pH of 7).

Alternatively, you can adjust the tap water close to neutral using vinegar or another mild acid as well.

You should add a wetting agent to the spray as well. This helps the iron penetrate the leaf surface and enter the inside the leaf. Otherwise the spray is not as effective. Some people use liquid detergents with good success. I worry a little bit about the other personal care products in liquid detergents so I would encourage you to use a commercial wetting agent.

If you are still unsure how to do this, you can read more about how to do this on my blog or email me at extremehort@aol.com

Fertilizer Injectors Have Advantages and Disadvantages

Q. I know of fertilizer systems which friends have linked to their home yard watering systems. These can be adjusted as to the quantity of fertilizer added to the water. However, it seems this might be quite a bit of fertilizer applied to the plants. Yet, a neighbor is very enthusiastic about the benefits. Can you advise me on this subject?

Simple fertilizer injector using a stock tank of a fertilizer dissolved in water. Here we are preparing the stock solution to be injected into the irrigation line using the Venturi effect. In Kosovo.

A. These fertilizer systems have different methods of injecting fertilizer into the water. They range in different prices based upon how precise they can deliver fertilizer. Collectively we call them fertilizer injectors. They can be adjusted so they deliver a very tiny amount of fertilizer or deliver a lot of fertilizer at one time and then turned off until needed again.

The fertilizer was injected into the irrigation line and was applied with overhead drip irrigation using micro sprays. This is seedling production in a greenhouse in Kosovo. Benches were created using bales of straw.

Background. Fertilizer injectors were designed primarily for agriculture and commercial horticulture use where one type of plant is grown or plants grown with similar water and fertilizer requirements. Their primary purpose was to save the cost in applying fertilizer.

Several types of injectors are available for home landscapes in a range of prices. The primary difference in these injectors is their level of precision. Most inexpensive homeowner fertilizer injectors operate on the "venturi effect". The venturi effect pulls a concentrated fertilizer solution from a bucket or small tank into a stream of water. This stream of water might be in a hose or an irrigation line. The principle of the venturi effect  is used in some automated pool cleaners, wine aerators, recoilless rifles and in the pressure regulator for scuba gear.

You can watch how the Venturi effect works in irrigation lines in this video from Jain Irrigation
https://www.youtube.com/watch?v=tGlZLwvI6PY

The venturi effect causes concentrated fertilizer solution to mix into the stream of irrigation water. You can operate your injector to apply fertilizer continuously or periodically on a fixed schedule; once a month; once every three months, spring and summer, etc. If you put fertilizer in the injector, it will fertilize. If you don't, it won't.

Advantages and Disadvantages. The primary advantage to the homeowner is less labor which saves time. Some may argue it also saves the homeowner money and the landscape looks better. Both are arguable but I don’t think anyone can argue it is not a timesaver. I will go into more detail on my blog.

The primary disadvantage for homeowners is that all plants which receive water at the same time also receive the same kind of fertilizer. When fertilizing plants by hand, you have the option of giving them different types of fertilizers, not all the same kind.

Plants which receive more water also receive more fertilizer and the reverse is true. The application of fertilizer in precise amounts should also require a very efficient irrigation system. These go hand in hand.

In short, make your decision based upon the saving of time and labor. All of the other points are arguable and may or may not apply. 

Operating Your System. Leaving water with fertilizer in it in your irrigation lines for more than a few days can lead to algal, fungal and bacterial growth. It is best to apply fertilizer and allow fresh water to clean the irrigation lines after the fertilizer has been applied. Make sure there is a screen filter downstream of your fertilizer injector to prevent plugging of your drip emitters.

New Product for Lowering Soil Alkalinity (pH)

This was a very interesting product. When a few ounces were mixed with tap water it dropped the pH of the water to 3.1. We do not have that many good options for lowering soil pH. The sulfur we get now is coarse and takes years to break down.This product breaks down quickly with applied water. It gets me wondering about our acid-loving plants like azaleas, rhododendrons, hydraneas, camelias and the like. I also wondered about southern highbush blueberries and their potential here if we could find a suitable product to lower soil pH. It might also help plants that struggle with iron problems like photinia, bottlebrush and mock orange. It might be worth a try!

Viragrow Delivers! : New Product for Lowering Soil Alkalinity (pH): Have you wanted to grow southern highbush blueberries in the Mojave desert but the soil pH was too high? How about azaleas and rhododendron...

Call For Nominations to NOSB (National Organics Standards Board)

The Agricultural Marketing Service is pleased to invite nominations from qualified individuals to serve on the National Organic Standards Board (NOSB) from January 2016 to January 2021. Applications are due by May 15, 2015.

NOSB: Call for Nominations

The National Organic Standards Board (NOSB) is a Federal Advisory Committee that provides advice and recommendations to the Secretary of Agriculture on the implementation of the Organic Foods Production Act.  NOSB members are volunteers and come from across the organic community. Each member is appointed by the Secretary of Agriculture to a five-year term.   USDA seeks nominations for the following five (5) positions on the NOSB:   Two (2) organic farmers/producers, Two (2) public or consumer interest group representatives, and One (1) USDA accredited certifying agent.   Committee member duties include:   Attending committee meetings (travel paid by USDA) Participating in bi-monthly subcommittee conference calls Reviewing materials and/or recommending changes to the National List of Allowed and Prohibited Substances Advising the Secretary on other aspects of the USDA organic regulations   Written nominations must include a cover letter, resume, and an AD-755 Application Form, and must be postmarked on or before May 15, 2015. More Information:   Call for Nominations Flyer (PDF) Press Release: USDA Seeks Nominations for the National Organic Standards Board  Federal Register Notice: Intent to Renew Charter and Call for Nominations (Includes Application Instructions) (PDF)  NOSB Membership AD755 Application (PDF) Criteria for NOSB Membership (PDF) For more information: NOSB Nominations Webpage

Leafhoppers, Hornworm and Skeletonizer Reported on Grapes Now

Leafhopper damage to grape leaf. They are on the undersides of the leaves.

I received an email from a reader who reported leafhoppers already on grape leaves. I had another person report sphinx moths flying now (this moth lays eggs that make the hornworm) and another person reported skeletonizer moths (black or metallic dark blue) flying around the grapes.

Dead sphynx moth on the sidewalk. They lead to hornworms.

This came out of Arizona and southern Nevada but would be relevant for the low and middle desert elevations (500 to 3000 ft). If you had leafhoppers last year you can expect them this year. These are tiny little bugs that hop off of the grape leaves when you walk by them. Some people report that they "swarm" or fly off the leaves. They can't really do this but because they are so small and there are hundreds of them it may seem like it. To find them now you must look on the UNDERSIDES of the leaves.

If they are not controlled early, their numbers will begin to build over the season as they continue to multiply. Once the adults get established they are very difficult to control without using some very harsh conventional pesticides.

Skeletonizer moth.

Leafhoppers don't do a lot of damage to homeowner grapes except for the tiny black dots (feces) they leave behind on fruit and leaves. Commercially this is a problem. But they are a nuisance.

One of the most effective treatments when they are young is a spray of Spinosad. Spinosad is an "organic" insecticide. Even though it is organic, it is rough on bees so never spray if flowers are present. Spinosad is also very effective on the "worms" or caterpillars that you find on grapes. This includes the hornworm and the grape leaf skeletonizer.

I would make two applications of Spinosad to the grapes now and repeat it in about 10 days to two
weeks later. After this time inspect your grapes for these three pests and apply it when you first see them. Use a wetting agent like EZ Wet mixed in the spray. Use a hose end applicator or compressed air sprayer (best) and make sure you spray UP (the bottom of the leaves get wet). Repeat the spray on by spraying down (tops of the leaves). Spray just enough to wet the leaves.

Bt sprays will control the skeletonizer and the hornworm but not the leafhoppers. You must control leafhoppers early.

Pomegranates Produce Best in Full Sun

Q. I'm not getting a big crop of pomegranates this year. I have one Wonderful and one Utah, each about 6 years old. I had about 4 dozen fruit last year.  We have a large ash tree in the yard which throws some shade but the pomegranates both get morning sun.

Five-year-old pomegranate during winter

A. To produce fruit, pomegranate needs at least six hours of sunlight and does best in full sun. As shade increases, the number of flowers and fruits decrease.

Pomegranates produce flowers on new growth. If you are getting lots of new growth and there is
enough sunlight there is no reason you should not be getting lots of flowers. The key is the number of flowers it's producing. If the tree is not producing flowers it can't produce fruit.

If you have lots of flowers but few fruit then the problem may be insect related, e.g., leaf footed plant bug.Check the plant for the presence of this insect on the leaves.

To stimulate flower production it needs quite a bit of water to push new growth. The amount of water depends on plant size. A six-year-old pomegranate should be at least 6 feet tall and 4 or 5 feet across.

Pomegranate requires as much light as possible for good flower and fruit production.
Reduced light causes a reduction in flowers and fruit.

Another indicator of water is leaf density. The plant canopy should be so dense you can't see through it. If it is not dense, it's not getting enough water. Annual fertilizer application is important in quality production.

Pruning comes into play but if pomegranate is not pruned correctly it still produces lots of fruit but the fruit will be smaller in size.

Give the pomegranate as much light as possible. Remove lower limbs on the ash tree for better production, apply a fertilizer in early spring to push growth and make sure it gets plenty of water.

Water Needs of Gopher Plant Different in Small Containers

Gopher plant of readers growing in container

Q. My wife and I are fairly new to the Vegas area.  She is the gardener and we are trying to grow gopher plants in containers. The containers are about 12 inches in diameter and the plants are not doing well. They are watered once every week or two and we added a plant tonic two weeks ago. 

A. Gopher plant does very well in our climate planted directly in the soil or in containers. Remember that the stems die after flowering. Flowering is normally in the spring and sometimes again in the fall.

Cut stems back to the ground after flowering. There will be some small stems growing from the base. You must let these grow and not cut them back. Fertilize lightly after cutting back.

The two basic problems with gopher plants are either related to the soil that is used or irrigation practices.

If this plant is watered too often you will kill it. If you do not water it often enough you will damage it. If the soil used does not drain easily, you will kill it. The usual reason for failure is watering too often and poor water drainage.

I have had good reports from people using cactus juice fertilizer
on cacti and succulents. Let me know how it works for you.

When planting this in a container make sure that you use a soil mix made for this type of plant. A cactus and succulent soil mix would be preferred. It will struggle if you planted directly into our desert soils without improving them.

The plant is easier to maintain if planted directly into the ground. Make sure you amend the soil so that it has good drainage. It will do well in a soil that contains compost.

It will handle low winter temperatures but could be damaged if winter temperatures get extremely low, into the teens for instance. Fertilize it with a cactus fertilizer such as Cactus Juice every 2 to 3 months when you water.

I have two or three postings about gopher plants on my blog. Type in gopher plant in the search engine and see if that information helps.

Posts on my blog that you can click on which are related:

http://xtremehorticulture.blogspot.com/2014/11/what-killed-my-gopher-plant.html

http://xtremehorticulture.blogspot.com/2014/05/gopher-plant-adds-interest-to-desert.html

Harvested Hard Peaches Will Ripen

Q. I just picked all these because the birds were getting them. Will they ripen enough to eat?  I covered the others with netting that are still on the tree   Do I need to put them in the sun or in brown paper?

A. Pick them! They will ripen at room temperature in 2 to 4 days I would guess. If you can keep the humidity up in some way it will reduce their water loss. 

But keep them at 65 to 80F if at all possible and out of the sun. They do not need to be in paper bags. Once fully ripened you can put them in the fridge.

Peaches Can Be Harvested Early

Q. Can I pick peaches when the color starts and will they ripen?

A. You can pick peaches when the color begins to change from green to yellowish green or even beyond. I prefer to wait at least until the color has solidly changed from green to yellow but are still firm.

Peach fruit with color breaking from green to red. They can be harvested at
this stage and they will ripen but the quality will be lower than if they were
left to ripen to a more mature stage on the tree. Birds are not yet interested in
them at this stage.

At this stage they will continue to ripen after they are harvested if they are kept at room temperature. They will develop better flavor if left on the tree as long as possible. If birds are not a problem then I prefer to leave them until the fruit has changed color and the flesh has softened just a little bit from being hard as a rock.

At this point, the birds are looking at them and not quite sure if they want to peck them or not. This is the stage also when some of the more hungry birds will peck at them anyway. When I first start to see bird damage I know I’d better get them off the tree.

What Causes Apricot Fruit to Drop?

Q. I've had my apricot tree about 15 years. Last year it had a huge crop. This year it had lots of blossoms, swarms of bees, but almost no fruit set. The remaining fruit has dropped off. There is sap on one of the branches and I'm wondering if it has bugs or is it just is taking a year off?

Plum fruit turning yellow due to lack of fertilization (talking flower sex, not fertilizers). Other fruits, green, set. The yellow
ones drop from the tree during "June drop" which actually occurs in April here. Yes, I know the question is about apricots but
I do not have any apricot pictures like this.

A. Some fruit trees do take a year off. This is called alternate bearing. However, alternate bearing decreases fruit production by reducing the number of flowers, not the dropping the fruit. Unless the tree is dying I doubt it is due to sap and the bugs.

See the "yellow" plum getting ready to drop? It will abort. The green ones
will continue to develop.

Flowering, followed by the dropping of small fruit, usually indicates poor pollination. Small fruit drops because the pollen was not transferred to the female part of the flower. Or, if it was transferred, it did not result in fertilization.

When fertilization doesn’t occur, fruit may still form, grow a little bit in size, but then yellow and abort or drop from the tree. Fruit abortion typically happens when the fruit gets about the size of a dime or even smaller.

Healthy fruit may abort if the soil is too dry. When soil dries, fruit trees will try saving themselves by first dropping fruit and, if the threat persists, dropping leaves as well.

If weed killers are sprayed close to a tree and the spray (even fumes from the spray on a hot or windy day) may drift toward the tree and cause fruit drop.

Applying too much fertilizer close to the tree trunk can also cause fruit drop.

There are a couple of older apricot varieties that need pollinators. If it is one of these varieties and a neighbor's tree died that was pollinating it then this might also be a problem.

Inspect your tree for insects. Some insects, such as the leaf footed plant bug, can cause fruit drop. If your tree had a large number of these insects feeding on small fruit, it could cause fruit drop. 

Black Spots on Tomato Leaves May Be Septoria

Q. I have these small black spots developing all over my tomato leaves. Any idea what is wrong with my tomato plant? 

Possible Septoria leaf spot disease on new transplants

A. From your pictures it looks like you could have a couple of things going on. The tiny black or brown spots on the leaves may be a disease called Septoria leaf spot. As a precaution, I would apply a fungicide for vegetables immediately and follow the label directions to a tee.

Any general fungicide for vegetables will work. It usually requires several applications in sequence. Push some new growth with a light application of a tomato fertilizer.

Another shot of possible Septoria.

Fungicides are primarily meant for disease prevention, not for curing a disease once the plant has it. Applying a fungicide protects new growth as it emerges so new growth should be healthy while the infected growth does not get worse.

The other option is to pull it out and start over.

Secondly, never apply irrigation water with a sprinkler; use drip irrigation.

If you bought these plants from a local store it probably came with the plant when it was grown in the greenhouse and shipped to the store. This disease is fairly easy to control if a greenhouse is kept clean and the plants kept healthy.

Such is the problem when buying low-priced transplants. They were most likely infected when you bought them. There were probably some leaves already showing these spots.

Your other pictures show leaves of tomato with edges that are scorching. These scorched margins have a yellow inner margin. This is possible salt damage.

Reminds me more of salt damage but ......

Soak the soil with water. Use a soil wetting agent like EZ Wet or comparable and apply it to the soil to remove salts. Hopefully you amended your soil with compost at the time of planting and you used a pre plant fertilizer.

Also some leaves showed signs of yellowing which may be due to lack of fertilizer applied at the time of planting. Once tomatoes start setting fruit it is important to feed them lightly to continue healthy growth.

Take a look at these fact sheets and pics.

Cornell's Fact Sheet on Septoria on Tomato

Missouri Botanical Garden Fact Sheet on Septoria on Tomato

Deformed Lilac Leaves Maybe a Sign of Problems

Q. My lilac bush had some leaves on it that suddenly look like they are deformed. What is the problem?

A. Deformed or crinkled leaves can indicate several things. If the edges of the leaves were damaged, scorched, the interior of the leaf will continue to grow while the dead margin will not. This can cause leaf deformity called cupping.

Stink bug

Feeding damage by some bugs on leaf buds before they open can cause crinkled or deformed leaves. These include the stink bug group of insects such as the leaf footed plant bugs. Look for bugs on the
bottom of the leaves or crawling on stems.

Leaf deformity can be caused by “weed killer” sprays that drifted on the foliage during windy or hot weather. Some herbicides, like dandelion killers for lawns, cause leaf deformity if it comes in contact with leaves as they are enlarging or expanding.

Squash bugs, one of the stink bug types

Bottom line, most likely the damage is temporary and as more leaves develop they should be normal. However, if you inspect the plant and see these types of insects apply an insecticide for ornamental plants and spray leaves and stems during early morning hours. Spray the undersides of leaves because this is where most the bugs hang out.

Make sure the plant gets enough water. This is a plant that likes compost and wood mulch, not rock mulch. Lilacs do not like rocks covering the surface of the soil. Every year apply 1/2 cubic foot of compost on top of the mulch and water it in. Use a high phosphorus fertilizer that promotes flowering of woody plants.

Mildew on Roses Have Common Link

Q. My roses are covered with mildew.  I have sprayed them and hope they will recover.  I have not had this problem in years.  What causes mildew and how do you keep it from coming back?

Powdery mildew of roses, severe

A. Diseases develop on plants when the environment is just right for that disease, disease organisms come in contact with the plant and the plant must be susceptible to it.

Let’s break each of these factors down. Remember, when dealing with diseases it is most important to prevent diseases from happening rather than cure them with a pesticide after the fact.

Powdery mildew of roses, or powdery mildew of any plant for that matter, develops best in shady spots during cooler times of the year and when it is moist. It does not like to develop in full sun and when it is hot and dry.

We see powdery mildew during cool weather of spring and fall and times just after it rains. It is common when roses are grown in shady spots and watered with sprinklers.

Powdery mildew of weeds

Powdery mildew can be spread by splashing water. This can be from rain or sprinklers. It can also be spread by hands, pruning shears and wind.

Powdery mildew likes some roses better than others. The variety of rose and how healthy it is has a lot to do with how often you will see powdery mildew on it.

So if you want powdery mildew on roses then grow a variety susceptible to powdery mildew, don’t fertilize it very often, prune it incorrectly, place it in the shade and water it with sprinklers.

The flip side is best for disease free roses: select a variety resistant to powdery mildew, plant it in at least 6 to 8 hours of full sun each day, apply compost and wood mulch to the soil, keep it healthy with at least one application of a rose fertilizer every year and irrigate using drip irrigation.

These links may help you with some general information on powdery mildew.

http://xtremehorticulture.blogspot.com/2014/12/euonymus-plants-have-white-spots-and.html

http://xtremehorticulture.blogspot.com/2015/01/pick-right-variety-of-roses-for-desert.html

Hugelkulter Mound in the Desert?

Q. I have been reading about building a Hugelkulter mound. My husband and I are in our 60's and the less we have to be on our knees the better it is for our backs. I wonder if we could build a Hugelkulter mound out of desert materials? Every article I've read seems to be in a forested area where wood is readily available.

A. I have to be honest with you. I have never heard of this before so I had to do some digging (not literally) into the subject. I also have to admit I don't know anything about it but I did find someone to refer you to. I met her a couple of weeks ago at a class I was teaching in Arizona.

Hugelkulter on Wikipedia

She is a permaculture advocate and a delightful person. I have not visited her place in Arizona but she is enthusiastic and someone I would recommend you contact for more information.

Christine Baker

928-564-2642

christine@highdesertpermaculture.org

www.highdesertpermaculture.org

Perhaps there are others out there who can chime in. Let's all remember this IS the Mojave Desert.

Consider Banks Rose in Desert Landscapes

Bank's rose is not a repeat bloomer so it only blooms once in the spring. The rest of the year it is green.

Yellow Banks Rose

Trellised for a western exposure and filtering light on a hot summer entry. Spring.

Fuzz Balls on Oak Leaves Damage

Q. I found these fuzzy things on my oak leaves. What are they and should I be concerned?

Oak leaf gall caused by  tiny wasp

A. These fall under the general category of plant galls. Galls are swellings of plant tissue and located on the roots, stems, trunk, leaves and flowers. Galls can be caused by insects, diseases, nematodes or mites.

This particular gall is on the leaf of oak, and my guess it is ‘Heritage’ live oak. These leaf galls are very common to oak and caused by a tiny wasp. The purpose of the gall is to protect the developing youngster until it is mature and exits the gall to find a mate.

Later on in the season you will see a small exit hole and the gall will probably turn brown or the leaf may turn brown and drop from the tree if the infestation is quite severe.

Ash flower gall caused by eriophyid mites feeding on flower buds

The basic lifecycle is for the female to lay an egg inside the leaf or on a leaf surface. The egg hatches and the very tiny larva eats the plant tissue inside the leaf. It also releases chemicals that control the growth of the leaf around the area where it is feeding.

This disturbed area grows in response to the feeding and causes the leaf to grow into a tumor-like growth totally surrounding the youngster. Inside this gall the youngster can continue to feed protected from predators and the environment.

Eventually the youngster grows up into an adult and exits the gall in pursuit of a mate. Once the mate is found, the life cycle repeats itself. In some cases a large number of these wasps can exit numerous galls and build a large population that can cause leaf drop.

These leaf galls normally don’t present a problem and I would just ignore them. However if they do create a problem you might consider applying a tree systemic insecticide to the soil surrounding the tree near the source of irrigation water. I would apply it as soon as you see leaf galls developing in the spring.

A picture of this same oak gall appears at this website by Armstrong with a short description along with a bunch of other galls. http://waynesword.palomar.edu/pljuly99.htm#insects

You can learn more about plant galls by visiting this website located at Brandeis University.

http://www.bio.brandeis.edu/fieldbio/Plant_Galls/samplepage.html

Leaf drop could also occur from excessive shade and a lack of water or applying water too often. You should not be watering daily. All it takes is one or two missed irrigations and you could have leaf drop from a lack of water during hot, dry weather.

Watering too often would cause root rots and leaf drop and a sudden death of the tree during hot weather.

Applying a heavy dose of nitrogen fertilizer close to the trunk could also cause leaf drop and possible tree damage.

No Water? No Vine.

Q. Is there any decorative vine which will prosper in Southern Nevada with no irrigation at all except what nature provides? The situation is the bare-looking north side of a wall where I do not want to extend irrigation piping.

A. There is no vine that will make it here without additional irrigation. We average 4 inches of water each year. I have seen it without rain here for over one year. That irrigation might come from a neighbor but it will not survive without some source of water.

We do have wild grape and some other vines that do grow along waterways coming from mountain runoff but they have water and grape roots can grow to depths of 30 or more feet.

The key to avoiding a lack of water is to either store the water in modified plant parts like cactus or have very deep roots that can tap into a water supply that we cannot see.