Why Can't I Find a Decent Looking Rose at the Nursery?

Q. My roses are not what they should be.  Not sure why but here is what I think. The plants we buy are not the same quality purchased 10 years ago, no matter the cost. The alkaline water has destroyed the soil and I am not using enough soil sulfur.

A. I do not agree. Rose producers, such as Weeks Roses, ship good quality roses when they leave their production facility. What happens to the roses after they leave their facility has some impact on the quality of the rose that you can purchase.

First is the shipper. If the shipper is a good one, they can arrive in the nursery in good condition. Damage to plants can occur in shipping.

Secondly are plant brokers. Sometimes plant materials are handled by so-called “middlemen”,  typically called plant brokers. Sometimes the brokers ship directly from the producers. Sometimes plant brokers have their own facilities and hold plant materials for a period of time. Damage can occur during plant brokerage.

Finally the retail outlet may mishandle the plant materials in the nursery prior to sale. Shopping at mass merchandisers or those companies which offer the lowest possible price will affect the quality of the plant. They shop around for the best possible deal they can get. This can mean the plants that have been held for quite a while because they could not be sold.

Anytime you hold plant materials for long periods of time the quality of those plants would be affected. Count on it. This is why the producer can start with high quality material and end up with a garbage with their name on it at a retail outlet  six months later.

There is definitely a difference in quality among producers of roses. But all these other factors will affect the quality of the product available to you. To avoid this as much as possible, do your rose shopping when shipments of roses first come in to the store. Minimize the time they stay at a retail outlet. Buy roses from a reputable grower such as Weeks Roses.  I know at least one nursery in Las Vegas carried Weeks Roses this past spring. They probably had trouble selling them, particularly in this economy because they cost more.

http://www.weeksroses.com/

Lastly, buy varieties of roses that do well in our desert climate. I have attached a list of roses that do well here for you to look at. I also posted this list on my blog.

Roses for Hot Dry Climates

The alkaline water does not destroy the soil. Water high in sodium can damage soil structure, be toxic to plants and cause serious growing problems.  Unless you are using softened water from your water softener, local water used for irrigation should not be a problem.

 The five tenets for growing roses successfully in the desert include: start with good quality plant material; choose the right microclimate in your landscape; amend your garden soil at the time of planting; cover the soil with wood mulch after planting; and use appropriate management which includes irrigation, fertilizer applications, pest control and pruning.

Agave Dying Suspected Overwatering But...

Q. The Agave in my front yard (maintained by HOA) is dying.  I was informed by an Aborist that it was getting too much water.  I relayed this to the HOA maintenance and when they looked at it they said it needed more water and ran another dripper line, which drips about every day. Can this once beautiful plant be saved. Pictures are 6 weeks apart and show how it has deteriorated.

Agave appearing to wilt from a watering problem, or is it?
This could also be from the agave weevil.

A. This is either too much water or agave weevil damage. The weevil deposits eggs in the crotches of the leaves at the base and the eggs hatch. The larvae of the weevil then invade the roots where they feed causing the agave to collapse just like in your picture. However, overwatering can cause the roots too rot easily and cause exactly the same type of symptoms; collapse of the outer leaves and eventual death of the entire plant. Unfortunately you get the same result and is not much you can do at this stage.

            I would predict the plant will die and it will have to be removed. American agave is probably one of the worst ones for agave weevil infestation. Replanting with a different agave like

Agave weevil in the roots of an agave. It is a light colored
or white grub near the center of the picture.

            Weber’s or Parryii will be more resistant to the weevil but not overwatering. Both of these are smaller and more in scale with homes landscapes.

            There are two types of overwatering. One is watering too much and the other is watering too often. This is more of the watering too often kind of problem. Wish I had a better story to tell.

            I have attached a brochure from the U of Arizona on this weevil problem and some recommended preventions from one of the arboreta down there. I also attached a picture of the weevil larvae you would find in the roots if that was the cause. They would be there now.

Papaya Growing By Accident. Can I Keep It?

One type of papaya. Fruit are borne on the
trunk like so many tropical fruits.

Q. I accidently have a papaya tree growing in my yard.  When we moved in I setup a compost bin.  Unfortunately I didn’t think about the irrigation pipes when I placed the bin and I eventually had to move it to fix a leak.  My wife had a thing for papayas while pregnant so quite a few papaya seeds went in to that bin prior to me moving it.  After moving the bin one of the seeds sprouted.  I didn’t know what it was at first and just let it grow out of curiosity.  My wife eventually identified it and, since I now knew I was growing a tree right on top of a pipe, I had to move it as well.  That barely succeeded and it almost died but eventually made a comeback and is now thriving at two feet tall.  Now I’m concerned about getting it through the winter which brought to mind your article in the weekly and I thought I would bounce the concern off of you.  I’m thinking about building a simple green house from sheet plastic and pvc pipe.  Would that work or should I take a different approach?

A. Very interesting story. Yes, I have encouraged people to consider papaya in Las Vegas because there are some varieties like the Hawaiian Solo types which are highly productive and some can bear fruit nine months after planting from seed. You can find seed sources online and refer to this website for growing instructions in mild climates.

http://www.extento.hawaii.edu/kbase/crop/crops/i_papa.htm

They will grow in the Phoenix area as evidence on this website

http://www.phoenixtropicals.com/papaya.html

         

Papaya in container

For our area the two enemies will be climate and soils. So you will have to modify both of these if it is to work. In the temperature end you have to consider the heat as well as the cold. I would pick a location in the yard that has some protection from the late afternoon sun as much as possible.
 

            However the plant will need lots of sunlight so make sure it gets it in the morning hours up to mid-afternoon. Winter cold will kill it for sure. So it will have to be protected from windy locations and a structure put over the top during night time.
 

            This structure could be opened during the day when temperatures are above 50F. Throw a blanket or protection over it when it gets cold at night. The papaya is a tree that grows straight up  so you will not be able to keep it very long before it is too tall. So plant in succession or even annually.
 

            Next is soil modification. The soil must drain easily and add lots of compost and phosphorus based fertilizers at planting time. This could be a lot of fun for you to try.

Weed Control in Lawn of Spurge

Q. Our Association Lawns are infested with a weed that spreads rapidly. We have been told it is spurge. Some owners have been told by a nursery that spurge control is accomplished by spraying in June and approximately every 6 weeks through the summer. Others have said that spraying can't be done when it is very hot. Please give your opinion on this matter.

Prostrate or spreading spurge

A. If this is spurge you are fighting it is a very poor competitor with a lawn. Most of it can be kept out by increasing the competitiveness of your lawn by following a few rules:

•           Keep the lawn dense by keeping its fertilizer program current.

•           Make sure it is getting water at the right times and avoid stress during the summer months and starting in February for spurge.

Closeup of the small leaves of a spotted spruge. Not all spruges have
spots on their leaves but all spurges have white sap or latex. So if you
want to know if your weed is a spurge, break the stems and look for the
white sap or latex.

•           Irrigation system must apply water evenly to the turf area. Get rid of mix and match nozzles and make sure the system applies water head to head.

•           If this is fescue, all irrigation heads must pop up out of the ground a minimum of four inches. Replace irrigation heads that are less than this with four inch popups.

•           Do not use line trimmers to trim grass around irrigation heads or along hard surfaces like sidewalks.

Use a steel edger, not line trimmers to edge turfgrass areas.

•           Mowing height must be 2 ½ inch minimums.

•           You can use post emergent herbicides (weed killers applied after you see it up) such as Trimec or similar but the best weed killers are applied pre emergent, before the seed germinates in the spring. Visit Helena chemical in town to get your chemicals and visit with them about which chemical has been working best and the timing of it. Do it this winter before spring.

Controlling Bermudagrass Growing in.....

Common bermudagrass stolons creeping from the
lawn over a sidewalk. Hybrid bermudagrass
is much more restrained in its growth.

This is a queston frequently asked, "How do I control bermudagrass in......" so let's talk about it.

The big problem is common bermudagrass. It is spread by seed, underground stems called rhizomes that can grow under the surface of the soil for many feet and re-emerge in a new location. Sort of like "Whack-A-Mole". You pull it or spray it here only for it to popup over there. Below ground the bermudagrass cannot get the energy it needs from sunlight. It must rely on food supplies sent by the mother plant growing in sunligh OR live off of stored food in its stems.

It can also spread by planting, or accidentally planting, any of its stems above or below ground. For instance you can take the above ground growth, cut it up into small pieces, throw it on the ground, water it and it will start a new plant any place these cut up pieces fall. When we WANT it to spread like this, we call are planting by stolons or "stolonizing" the area. The hybrid bermudagrasses, the kind that are nice to grow like on golf courses, is planted exactly this way.

The underground stems that spread the mother plant to a new location all by growing underground are called rhizomes. The only difference between the above ground stems (stolons) and the below ground stems (rhizomes) is there location AND their propensity to either grow above or below ground. What you can do to stolons, you can do with rhizomes essentially. So if you cut up a bunch of rhizomes the same way as stolons and spread them on the soil surface, guess what will happen. You got it. You have a new lawn whether you wanted it or not.

Hybrid bermudagrass stolon (left) stem and
leaves (right) and rhizome (bottom)

Question for YOU. What will happen if you rototill a bermudagrass weed area in the hopes of getting rid of it?
Answer: You spread it.

So how do you get rid of bermudagrass weeds? You exhaust it. You kill it, let it grow a bit, kill it again, let it grow, kill it again, let it grow, kill it again...... In this way you begin to exhaust its stored food supply AND by constantly killing or cutting off its access to sunlight you deny it the ability to put more stored food into its food supply. In the end you exhaust it, weaken it and it dies.

You can deny it sunlight by constantly killing top growth back as soon as it gets exposed to that life-giving light a week or so. You can kill the top growth by mechanically whacking it off to soil level or below or killing it to the ground with a poison such as Roundup or even vinegar. Anything that will cause it to die to the ground and not hurt the surrounding environment. The advantage of Roundup is that it is systemic and will travel into the ground a distance and kill somewhere below ground level. To grow back requires more energy and so it will be more effective than just whacking it off or killing the tops.

The disadvantage is that it is a weed killer and it may have some adverse side effects. Other chemicals to look at include Poast and Fusilade which are also systemic weed killers and are potentially less damaging to surrounding plants.

Nothing wrong with a hoe, shovel and other tools that will help take it to the ground. Regardless, the secret to success will be to stay on top of it and never let it grow back more than a few inches before you knock it down again.

Praying Mantis Eggcase Confuses Reader

Praying mantid (mantis) egg case from reader.



Q. I would like to know what this was on my Royal Blenheim apricot tree in my backyard in North Las Vegas. It appeared to be hard and had circular markings on the part attached to the tree as thought it was an egg casing. I removed it and hopefully it was not a helpful insect. You may use the picture as you wish.

A. It looks like a mantid egg case to me. Please be careful. These are good guys and in the future leave the egg cases where they are or move them to a location where they will find lots of food and help you beat the bad guys.

Praying mantis (mantid) released on to sweet acacia to
battle cicadas.

 

Watering Citrus in Bullhead City

This is an irrigation basin around a fruit tree. The basin keeps
water contained near the tree where the roots are. This basin
receives its water from a bubbler (upper left inside the basin).
This particular bubbler puts out two gallons per minute if the
water pressure is adequate or above (it is pressure
compensated which means if the pressure is higher than
adequate it will still give only 2 gallons per minute)

I have three trees  planted in a “L” shape with the orange and lime on the bottom of the “L” and a lemon on the top. They are about 6 years old and the trunks are about 5” in diameter. They are almost 6 ft. tall and about 7 ft. in diameter. I have the three on a separate circuit with each having a 1/2 “ p.v.c. bubbler providing water every other day at 6:30 a.m. and 8:30 p.m. for 15 minutes. this fills a water well that is about 4” deep and 4 ft. across for about 10 minutes after the water goes off. The water is then absorbed into the ground.

            I have tried to let the water run longer but it seem's to want to go outside of the well and not deeper into the well. I thought about cutting down on the flow so it would run longer and maybe soaked in to the well better but I have not tried that. I have been told to water once every 90 days and let it run for 3 hours. I would have to cut the bubblers just to a drip or it would flood the yard. I don’t know what is the best option. I get a heavy crop of limes now but just a few oranges, and they are half orange and half green. any suggestions?  Remember this is in Bullhead City and it gets very hot during june thru sept

A. I forwarded your question to Terry Mikel, retired Extension Horticulturist with the University of Arizona out of the Phoenix office who knows your location very well. Here it Terry's response:

I am familiar with much of the Bullhead City soils and conditions but I have yet to hear that watering every '90' days  . . . I should think, or hope someone might have meant or you meant every '9' days .. . That would be certainly a point of clarification . .

Irrigating citrus in Hermosillo, Mexico, at USON's research
farm. This is ditch irrigation which is terribly inefficient but
still more efficient than flooding the entire field.
Water moves toward the roots from the ditch
through the soil. The most
efficient would be drip irrigation and would not need a basin
or ditch but is expensive for farmers with hundreds of acres.

            I personally avoid giving calendar or numerical days for watering . . There are too many factors; for example, are you near the river with a heavy clay soil or up on the higher ground where the soil drains much better? . . .

            It sounds like you are careful and meticulous about watching the growth and you should check the soil in the morning hours and water when it is dry down a couple inches . .  .Remember to check in the morning not in the afternoon when the heat will dry all soils there down a couple inches . . In the morning the soil will have the cooling  of the night to percolate water up from below thus rehydrating (fancy word for wetting) the upper soil zone . . . If you want to add more water and much more efficiently then change how you add the water . .

Set the repeat cycle to  whatever time it takes the initial water to move into the soil and then run the set again instead of spacing it out for hours . . This is called surge watering and it works much better than the delay . . . Maybe next summer you can try and see if you can go more days between waterings without impacting the plant . .

If you have a fast draining soil it might not work; likewise, if your soil is heavier you might . . . Don't forget that a nice thick layer of mulch on the soil surface saves a lot of water from being lost into the air through evaporation . . .

There are some great Master Gardeners in your area that are both knowledgeable and grow lots of things under your conditions . .

With respect to the lime's yield vs. the orange's yield:  My first guess is the orange is a Navel type orange . . They are notoriously sensitive to hot dry condition and their fruits drop like flies . .

The plant itself does well but the fruits you get are great but the number you get is usually a disappointment . . .It's almost a shame they are sold . . .

Terry Mikel

Fertilizer Formula for Keeping Crepe Myrtle Healthy in Desert Landscape

Q. We have a crape myrtle tree in our southwest back yard. It gets plenty of water and I fertilized it last month with some Miracle Grow flowering fertilizer. At the time there were some burned edges on some of the leaves and some yellowing. Now it is really burned on the edges of all of the leaves with yellowing. HELP!

Crape myrtle growing at Center for Urban
Horticulture for 20 Years on Formula
Mentioned Here

A. A couple of things on your crape myrtle. I have kept crape myrtle growing in raw desert soil in good shape for 20 years at the Center for Urban Horticulture and Water Conservation in North Las Vegas. I used a combination of a general purpose tree and shrub fertilizer (16-16-16) plus an iron application combined with foliar sprays of Miracle Gro.

            I don’t really endorse products but Miracle Gro is the one I used and have found to work just fine. You could just as easily use a different good quality foliar fertilizer for flowering woody plants. I apply the granular 16-16-16 in late January or early February using about 2 lbs. of fertilizer applied to the surface of the soil and watered into the roots without it washing against the trunk.

            You can make some shallow holes in multiple places under the canopy and water it in thoroughly. At the same time, I also apply an iron chelate, iron EDDHA at the rate of a tablespoon or two scattered in the same holes and watered in so that none of it remains on the soil surface. It is light sensitive.

            After about one month of new growth I then foliar fertilize the tree with a Miracle Gro spray or comparable product. I do both of these annually. You can do the same thing (except for the iron) by using a fairly large quantity of good quality compost annually. My guess is you either are missing the iron application, watering too often or not watering deeply when you do water.

Use Distilled Water or RO Water on House Plants

Q. I have a three house plants, a Christmas cactus, “Mother-in-Law’s Tongue” and an Orchid plant.  There is a white “fungus” looking on the top of their soil.  WHAT can I do to get rid of it?  Am I watering too much?  Indoors all the time.

 

A. It is difficult to diagnose without some pictures but this might be either a salt accumulation from using Las Vegas tap water coming from the Colorado Rivere or it could be fungus (mycelial growth) on the surface. Water taken from Lake Mead (Colorado River) at the Las Vegas location is carrying about six pounds of salt for every thousand gallons of water.


Our native desert soils also contain alot of salt. I assume your houseplants were potted with some commercial potting soil so the salt load is probably relatively smaller than our native desert soils. Over time this salt can accumulate in the soil (from the tap water and soil salt) and wick back to the surface of the soil as the water in the soil evaporates. This can leave a white crust on the surface.




Salt deposited on the soil surface from the Las Vegas
water coming from Lake Mead and soil salts left behind
when the water evaporates.

Remove the upper layer of the soil and repot the plant with fresh garden soil. Dilute your tap water with about 3/4 of the volume with distilled or RO water. I would not use pure distilled or RO water as this might cause some problems with your potting soils. Also when you water, make sure 1/5 of the water applied actually leaves the container out the bottom as drainage and discard. This helps to flush out the soil salts.

If this white thing is "fuzzy", this could be some fungal growth. Not all fungi are bad and some are decomposers and work to help break down organic materials that are already dead. Seldom do these fungi that feed on dead things attack healthy plants. Scrape off th surface, repot, keep air circulating around the plant and in sunlight when possible to help keep these fuzzies to a minimum.

How to Get Rid of Grubs in Your Compost Pile

Q. I started a Mulch bin about 10 yr. ago. It is about 4ft. by 6 ft. on the ground. Today when I went to get mulch for my vegetable garden and found a 1/2 dozen Grubs. How do I get rid of the grub and keep the worms?

A. First of I would like to refer you to a pretty extensive discussion I posted on my blog regarding composts and grubs in the compost.

http://xtremehorticulture.blogspot.com/2012/07/grubs-in-container-of-garden-soil.html

Grubs from compost pile

 Secondly, we have to remember that these grubs, like earthworms, are decomposers... they are taking raw products from your compost and helping to convert them into a soil amendment of very high quality through their gut. But we also know that these are potentially problem bugs when they mature so as you already identified it might not be a good idea to cultivate them.

If it were me, the compost pile needs to be turned regularly to aerate it so it does not get anaerobic or it will get all sorts of problems. So if you are turning your compost pile then expose these grubs for the birds. Have you ever seen birds follow a tractor that is cultivating a field? the birds know that during cultivation all sorts of goodies are exposed and looking for a free lunch.

The other problem you may encounter (I am not sure because it is not clear) is that your compost pile might be in some location where the birds cannot get to it such as a barrel composter or the like. One advantage that worms have over grubs is their ability to move faster than grubs can. If the soil is starting to heat up, they will go deeper quite quickly while the grubs cannot. So another alternative is to cover the compost with clear plastic and heat the upper layers of the compost but allow it to be deep enough so the worms can escape. Keep it at 165F for at least 30 minutes and let the grubs cook and then let it cool down. The earthworms will again migrate back up to the upper surfaces or through the compost. A third way is to remove the worms. Heat up the compost with solar energy (clear plastic again) and re-introduce worms after it has cooled.

I hope this helps.

When Do You Pick Bartlett Pear?



Bartlett pear. The pear on the left is ready for picking.
Notice the skin color change from green (right) to
yellowish green. Notice also the seeds in the pear
on the left are brown. The one on the right is still white.

Q. Just this year planted a Bartlett pear, and a Comice for a pollinator. Both have pears on them now. But I thought Bartletts were supposed to ripen in August. I picked one of my four pears, chilled it in the refrigerator for a couple days, then let it sit for about three more days before slicing it. It remained hard as a golf ball and no tastier. When are they supposed to be ripe? 

 

A. Bartletts are picked when the color of the pear turns from green to a yellowish green but still hard. Then you must put it at room temperature to continue ripening and turn soft and buttery. If you let them soften on the tree, which you did not do, the flesh will be gritty with all those stone cells in the flesh.

Corky spot on Comice pear

If you pick just as the outside skin turns color to light or yellowish green, the flesh has more of a buttery texture. The pear on the left is the right color for picking. Also, the seeds should be brown inside when ready to pick. We are not picking Bartlett until mid September.

Just an aside, Bartlett usually does not need a pollinator in most of the Western United States. It does in other parts of the country. Also, be aware that Comice tends to get corky spot in our alkaline soils and may require foliar calcium sprays to correct that.

There is Lots of Salt in Las Vegas Water and It Can Affect Plants

Q. I saw that on August 12th you responded to a question regarding yellowing leaves on a Meyer lemon tree.  My tree has similar symptoms - though the yellowing is more spotty and on tips.  You advised to "give it a long deep watering about once every few weeks...to supplement the regular water to leach out the salts..." (emphasis added).

            I realize that soil make-up effects watering needs, but can you give me a ballpark as to how many gallons of  "regular water" per week is needed for these trees in Las Vegas in addition to the leaching you recommended?  My tree is approximately 7 feet tall. Should I spread these gallons out over a few days a week, or is giving it these gallons slowing on a single day once a week?

A. That’s actually a very interesting question and we have some research to back up the amount. There is about one ton of different kinds of salts (all of these together make up the "salt" content) in one acre foot of water that comes from the Colorado River (Lake Mead). 

Rose leaf with salt damage

            An acre foot of water is about 360,000 gallons. Unless you are on a well, this represents about 80% of the drinking and irrigation water provided by water purveyors (Las Vegas Valley Water District in the case of Las Vegas) in the Las Vegas Valley.

            This sounds like it could be quite dilute but actually when you water to a lawn from Lake Mead it will carry 4/5 ton of salt for every 360,000 gallons that are applied. This translates to an application of 800 pounds of salt for every 1000 square feet of lawn area each year.

Salt damage to pineapple guava from salt in the irrigation
water

            Bottom line, if this is municipal water it carries a considerable amount of salt. If you skimp on the amount of water that you apply and don’t overwater a little bit, this salt will accumulate around the roots of plants. This "little bit" of overwatering each time you water is only about 15%.

            So if you apply 100 gallons you really should apply 115 gallons to help move the salts out of the root zone of plants. If it is 50 gallons, then apply an extra 7.5 gallons. Ten gallons means you should apply 11.5 gallons.

            Few people are this precise when they water unless they are watering a golf course and paying $1M each year to irrigate an 18 hole golf course. So when you water you can apply a little bit extra each time you water (15%) or you can flush out the salts around the roots by adding an extra irrigation or two during the hot months to keep those salts moving out. I hope this helps.

Where to Get Pheremone Traps

Delta trap with pheremone inside

Q. Do you know where I can get pheromone traps for insects that cause damage in our area and also for thrips that damage nectarines?

A. Try Peaceful Valley at

http://www.groworganic.com/weed-pest-control/organic-pest-control/insect-lure.html

            Pheremone traps can be used to identify what insect problems you have in your backyard orchard and when to spray. Commonly we use them for peaches, nectarines, apples and pears. You will want a trap for each insect and about three or four lures for each trap since they have to be replaced regularly. You will replace the lures about every 4 to 5 weeks until harvest then you can stop.

Wing trap with pheremone inside

            There are no traps for thrips. For thrips you will need Spinosad biological insecticide which you can get from local nurseries. The label may not say spinosad but may say something like borer, bagworm control. You may have to look at the ingredients to see the spinosad.

Must Cut the Roots of Italian Cypress to Put in a Block Wall

Q. We are thinking of taking out our wooden fence and replacing it with cinder-block wall.  The Italian cypress trees grow along 2 sections of the fence and are about 20 years old.  The new block fence will go on the other side of the wooden fence but there’s the footing to consider which will cut into the root system.  My question to you is, what are the chances of these trees surviving since we won’t know how much of the root will be cut into?  I can send pictures of the base of the tree with the irrigation and the existing fence post to give you a better picture of the area or I can send measurements of what I am planning.  Not sure if the pictures will give you enough detail to make an informed prediction. 

This is a picture of the soil around some oleanders after a
block wall had been removed and was being replaced. This
is not the readers but a friends. The oleanders were being
watered in a shrub bed with bubblers. Notice that there
is not alot of root development next to the wall.

As you know the trimming of these trees are time consuming and/or expensive to hire out.  We wonder if the block wall will bring more heat to the yard and could the heat from the wall burn the tree?   The reason we are considering this project is that with our dogs we are simply worried that if a plank snaps that our dogs will get out and possibly hurt.  We like to rustic look of the wooden fence but we wonder if the block wall might be a better choice for security.  Any thoughts on your part would be appreciated.
 

A. Let me talk about things I know something about, the damage to the trees if you decide to move ahead with a block wall, replacing a wooden fence.

    In the desert, plants grow where there is adequate water. If a good supply of water is on your side of the fence, the roots will tend to grow more in that direction. If there is lots of water on the other side of the fence, they may tend to grow in that direction.



Notice the difference between the shallow fleshy roots
of the palm tree (left) and the oleanders on the right. Palm
roots grow where there is more air, near the wall.

    So try to picture that your tree's roots will grow more in the presence of water. Would this be on your side of the wall or your neighbor's side? So if a cinder block wall is constucted, a trench will be dug and a footer laid to support this very heavy wall. You are right, this will definitely eliminate a portion of their root system.

   If these tree's roots are growing toward your neighbor mostly, then these trees will suffer significant damage. If your landscape is dry and the neighbor's is wet, this might cause severe damage to your trees.

    If their water is coming mostly from your yard and your neighbor's is dry, hen cutting the roots on the side toward your neighbor will probably have a more minimal effect.

This picture from Washington State University shows
how some plant roots will grow toward a good balance
of air and water such as close to the container wall.

    Likewise if their water is coming from a water source in small amounts from drip irrigation close to the trunk adn the resest of the yard is dry then the impact will probably  be minimal. In other words,if you are trenching in soil that stays dry for most of the year you will probably be okay.

    Another word of caution. The week before they put in the footer water the trees very well. Then let the soil dry out until they dig. Encourage them to dig, put the footer in and backfill the soil as soon as possible to minimize damage to the trees. As soon as possible, irrigate the trees again.

What Kind of Grass Do I Have?



If you see this on your sidewalk you have
common bermudagrass either
as a weed or as a lawn grass.

Q. We moved here last year and have not ever had the experience with the type of grass that is in our back yard. My husband says we need a four wheel drive lawn mower for mowing, extremely bumpy and patchy. What kind of grass seed should we be using here for this environment, and when to re-seed? Thank you and the Gazenias you advised me to plant and thick and healthy!!

A. It will be tough to tell but the two common grasses here are fescue (a bunching grass which might be giving you all the bumps) and bermudagrass. Bermudagrass runs along the ground and is flat. The bermudagrass, if that is one you have, will turn brown this late fall and early winter (November/December).

If you have a mixture of the two then you will see the parts of the lawn with bermuda turn brown this winter and the tall fescue will stay green in clumps. If you do have a mixture it is usually because of an inadequate irrigation system or not very good irrigation practices. The bermudagrass can survive with lots less water than the fescue. So when water is limited, the bermudagrass takes over those areas.

From left to right upper leaf surface of Kentucky bluegrass,
perennial ryegrass and tall fescue. Actually the tall fescue
leaf surface could also pass for annual ryegrass.

It is easy to spray and kill the fescue during the winter in the bermudagrass (beremudagrass is brown then and sleeping and will not get hurt) with Roundup but not the other way around. But most people do not like a bermudagrass lawn. Hope this helps.

Overseeding Bermudagrass With a Winter Grass

Q. My backyard has a bermudagrass lawn and I would like to overseed with a winter ryegrass seed. When I have done this before, I "burned out" the bermuda by not watering it, then rented a power rake to de-thatch it. This year with all the rain, my bermuda is not turning brown. My concern is if the lawn is green the power rake will not remove the thatch. Also, which do you recommend annual or perennial rye seed and why?

Dethatcher or verical mower.

A. Overseeding bermudagrass with a cool season grass like one of the ryegrasses has a window of time which is optimum in the fall. This window is from September 15 to October 15. If you overseed to early, the bermudagrass is too active and will compete with your winter lawn. If you overseed too late, you run the risk that it will get too cold quickly and the overseeded grass may not all germinate and fill in your overseeded area.

            The mantra for effective overseeding is having “good soil to seed contact”. In other words, the seed should rest on the soil when you overseed correctly. If the bermudagrass is too dense, much of the seed will not land on the soil and you will have a spotty winter lawn.

Common Bermudagrass stolon

            Sounds like you have the correct sequence for overseeding; time the overseed around October 1, September 15 turn off the water to the bermudagrass, September 21 mow as short as possible (rotary mower on the lowest setting is fine), power rake or dethatch until you see bare soil, apply seed, fertilizer, topdress the seed and fertilizer and water.

            Bermudagrass lawns are usually mowed somewhere from ½ to 1 inch high. I like to let it grow to an 1½ in August/September. This produces more stem so I can “scalp” it better and get the seed to fall onto the soil for that good soil/seed contact.

            You can use annual ryegrass if you want but it is coarse textured, light green and rough to the touch. Perennial ryegrass is a much prettier grass and soft to the touch. You can put all the nitrogen you want on annual ryegrass and it will just not get the same dark green color as perennial ryegrass. It is more expensive but will give you a much prettier lawn.

Vine in Lawn Turns Out To Be Bermudagrass

Q. I found this vine growing in my lawn and sent you pictures of it.  I tried treating it with Ortho's Weed Be Gone.  As of this morning I still have the vine.  Do you have any idea what it may be and how I can treat it or get rid of it?

Vine in lawn appears to be bermudagrass
or Devil grass.

A. From the look of this "vine", it appears to be bermudagrass. Some old timers call it Devil grass mostly because it is the devil to get rid of. Once it is in a lawn, it is tough to nearly impossible to get rid of.

            It is easier to get rid of if it is in a shrub bed. Then you can cut it back to a foot long (as long as it has leaves) and "spot spray" what’s left with Roundup. Other products that have reasonable success at some control include Poast and Fusilade which can be used fairly safely among shrubs and groundcovers.

            Bermudagrass gets in a lawn usually if the lawn begins to "thin" or lose its density. This is because it is not kept full and dense. This can be because it is not fertilized regularly, mowed too short or an insect or disease problem.

            Mowing too short can occur by lowering your mower too close to the ground or by using a line trimmer and whacking the grass low around sprinkler heads or along the edge of the lawn to make it look pretty.

            The best defense is a good offense. Keep the lawn at 2 to 2 1/2 inches if it is fescue. Keep it fertilized regularly. If patches of the lawn die, do not disturb the dead area and/or reseed or resod until mid to late September when bermudagrass is going to sleep.

Bay Leaves Browning and Yellowing

Q. I have several bay leaf bushes but one appears to be dying.  What can I do, if anything, to nurse it back to health?

A. Two things are going to be a problem for you, maybe three. First, judging from your picture, it is in rock mulch. This plant will not handle a rock mulch environment very well. If it is going to work for you in rock then it should be in an eastern exposure where the wall would be to its west.

Picture will not insert properly in Blogspot. Bay Leaf of reader.

            If your plant is in this environment then it might be getting hammered by being fully exposed to the southern sun as well. It will do much better with some protection from that hot, blazing sun in the summer. That is why you are seeing the leaves with brown tips and edges.

            Secondly is the yellow color developing on the new leaves, leaves at the ends of the branches. Most likely this is a nutrient deficiency due to the poor nutrient capacity of that desert soil. Rock mulch adds nothing to a desert soil. It needs a more fertile soil and should not be planted like it is growing in the middle of a desert somewhere.

            Thirdly, you might have trouble keeping it through the winters here. It is not terribly tolerant of real low winter temperatures. If it is in the open and can get hit by cold winter winds then it may freeze back yearly or every few years when we hit a good cold spell.

            I would move it to a new location this fall, about mid-September to October. Move it somewhere where the sun won’t hammer it after noon or two PM. Heavily compost the soil when you plant it. Use organic mulch around it, not rock mulch. Put it somewhere the plant will be protected from freezing winter winds. Hope this helps.

Lack of Fullness in Japanese Blueberry

Q. I was referred to you by Lori, a Master Gardener re: my problem with my Japanese Blueberry trees. I have planted 3  in November 2009, they are about 7 ft tall, 4 ft wide, trunk column about 3 inches in diameter . Leaves seemed to fall prematurely, browning and yellowish. One of the trees bark is peeling off and appeared to be dry. I have 3 sprinkler tubes on each tree, dripping 1 gl/hr each (I think). There's no visible insects but I do not know what to find anyway. Leaves seemed scarce, does not have that fullness that other trees does.  I have not sprayed them anything, no fertilizer or some sort. I put some manure compost 2 months ago. I am a novice on gardening so my description might seem funny. I can send some pictures if that would help. I have spent so much money on them for them to die. Please help.

Japanese blueberry along a block wall in rock mulch

A. Japanese blueberries will require a soil that is a composted at the time of planting and an organic mulch on the surface of the soil after planting.  It will do terribly in south or western exposures in full sun or in rock mulches.  If you planted this Japanese blueberry from a 15 gallon container then it will require about 15 gallons of water each time you water.  

The amount of water must increase from this amount as the plant gets larger from year to year.  This can be accomplished by adding minutes to your existing irrigation schedule at each watering or adding additional emitters.  If these are 1 gallon per hour emitters and there are three of them then the irrigation run time for this tree should be somewhere around 5 hours for it to get adequate water.  

Water requirement curve for the Las Vegas area. The first bar (1) is January
and the last bar is December (12). You can see that water demand by
plants increases 400% from January to July and August.

Unless this plant is getting water from other sources it will be under watered if you are irrigating for only one are 2 hours.  The frequency of application of the water, but not the number of gallons per application, will vary from season to season.  There is generally are a winter schedule, spring schedule, summer schedule, fall schedule and back too a winter schedule which means you should increase the number of times you irrigate per week about four times each year.  

These schedules will coincide approximately with December 1, February 1, May 1, mid June, mid September and finally December 1 which completes the seasonal cycle.  

Because your plant does not have the fullness that caught your eye I would assume it is due to improper irrigation which may have led to infestation with borers.  Pull off the loose bark at you see and look for damage in the wood do too boring insects.  This would include sawdust under the bark and perhaps elliptical exit holes from the trunk under the damaged area.  If the damage is more than half way around the trunk then I would replace the plant.

Yellowing on Meyer Lemon Might Be Magnesium Deficiency

Meyer Lemon with deficiency

Q. We have went to the nursery a couple times about this tree. First we got the water cycle correct, then iron was suggested which we did as they directed then Gold Dust was suggested. Online I read possibly the tree suffers from a magnesium issue. I thought these photos would give a better picture. All we did as directed and the tree is not responding in fact it is getting worse. I am wondering if it is because of where it was planted which is a confined root growing area. Any insight would be appreciated.

Meyer lemon another shot.

A. By looking at the leaves I have to assume this is a Meyer Lemon (which is, by the way not technically a lemon but an unknown hybrid found in a Chinese back yard by USDA researcher D. Meyer in the early 20th century). Your pictures are all pretty good with the exception of not showing a critical view of the trunk where it is just out of the soil. Just for future reference always look at and show this interface of the trunk and soil. W/o that view I have to only guess that the rootstock/trunk union is well out of the soil and we can eliminate that issue. And, a shot of the soil might show how the plant is getting watered. I have to assume drippers and I would guess they are in the same locations as when the plant was planted.

The leaves show two distinctive symptoms that often occur in concert: 1. There is some salt burn and 2. The common symptom that comes with salt issues is the magnesium deficiency. Just FYI Iron def. only occurs on the new leaves.

For the salinity (salt) issue we usually look first at the watering and with watering comes knowing if the water can even be applied uniformly all around the edge of the canopy, sometimes called the 'drip line'. Citrus are botanically a shrub with shallow and wide spreading roots that are tough to grow to maturity with drippers unless they are closely spaced in a wide band around the canopy's edge. There is one picture showing the plant is right next to a step wall with no water being applied in that zone of the root system.

I would not worry too much about adding any supplements and see if you can begin to manage a watering system of application that would give a long deep soaking water application out near the drip line. The 'soaker' hoses could be laid out on the ground out near the drip line and let it run for hours and hours to try and leach out the excess salts that may have accumulated over time with the drip system. Drip systems are fine but, due to their limited water output salts can begin to accumulate thus impacting citrus' sensitivity to salts.

Give it a long deep watering about once every few weeks from now on all during the growing season (May through October)  to supplement the regular water to leach out the salts that inevitably are deposited with the limited volume of drip systems . .This leaching watering is also the great time to add fertilizer and get it into the soil evenly all around the active roots near the drip line.

Terry Mikel

Gardener Moving to Las Vegas from San Francisco

Q. My husband found your site. We are facing the possibility of a move to Las Vegas. We have never lived in a desert climate. I am hoping to continue my love of gardening with vegetables, flowers, and a water garden like I have here in the San Francisco Bay Area. My biggest problems here have been raccoons, squirrels, aphids, and powdery mildew. Will any of those be things I will face in Vegas? What are the biggest pests/problems I should prepare for? (I'm praying you don't say scorpions or fire ants!)

            Also, my great love is dahlias. I have about 44 plants here, though ironically our summer was so cool that it was a poor year for us (our tomatoes were also a disappointment, and I sure hope that won't be the case in LV). How well to dahlias fare in Vegas, and will they bloom at a different time of year? Should I consider putting them in double pots and not in the ground (we've talked about raised beds with high quality soil)? Someone told me that grasshoppers are so bad there that I will need to completely fence in the whole garden area with small mesh wire to block the bugs out, is this true? What are your thoughts?

            I realize this letter contains a lot of questions... but any help you can give a life-long gardener or who very nervous she will have to give up all the plants she loves would be greatly appreciated

A. Well Shannon... we do have bark scorpions but we don’t have very many fire ants. Those are pretty rare and relatively easy to control so far. So take a deep breath... it’s not so bad. The desert can be beautiful.

            No raccoons in the Las Vegas area. No grey squirrels but we do have ground squirrels which some call chipmunks which they aren't but they do look a little like Chip and Dale. They can be pesky.

            We do have some aphids in the spring but they disappear when it gets hot. Powdery mildew is relatively rare compared to San Francisco. Dahlias will be tough for you in Las Vegas. We can produce some wonderful vegetables and fruits here and you will find them rivaling in quality to what you can find at the Farmers Markets in San Francisco.

Ground squirrel

            Now the bad news. This is the desert. Growing things here will be NOTHING like what you are familiar with. You will have to relearn your gardening skills and adapt them to the desert climate. Your new mantra will be compost, compost, compost. And everything will revolve around water.

            Yes, you have a lot to learn but think of it as an adventure and your gardening skills will be tested here. No "throw a seed in the ground and watch it grow" here. Thats why I am here. Feel free to ask. By the way, the grasshopper story is totally far-fetched. You will need a shotgun. (Just kidding, it is not that bad ......... most years) :-)

Maybe some others here can give you some pointers.