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Saturday, September 20, 2014

Wednesday, September 17, 2014

Sunday, September 14, 2014

Tree Replacement for Ash

Q. I am particularly having trouble with a tree to replace the ash trees that doesn’t grow so tall and does well in our climate. We took out our ash trees because they were giant and the roots were all at the surface. I am now guessing we have a soil issue?

A. I no longer recommend ash trees for our climate. We have had too many problems with them over the years.
There are a number of smaller trees that work well in our climate. It is hard to give you direction without us going back and forth a lot. It is simpler if you go to a nursery and develop a list of four or five trees that appeal to you and I can help you narrow them down.
Shallow roots usually indicate a very heavy soil or shallow irrigations or both. Planting in our desert soil requires a lot of soil preparation where the tree is to be planted. That is a major key to success.
The second major key is irrigation, both the proper amount and the timing when to apply it. Make sure your trees receive enough water each time they are irrigated. Space near irrigations far enough apart so that the soil drains adequately before the next irrigation.
Thirdly, I would include in that using a surface mulch of wood chips after planting. Although not needed for all plants, woody plants that are not from desert climates do much better if a surface would mulch is applied.
I can hardly wait for the criticism on this list! Please, let's make comments constructive. Medium sized tree, tolerant to at least 20F.

Some possible replacements for ash:
Fruitless olive (allergy problem)
Chitalpa
Chinese pistache (large tree)
Evergreen elm (large tree)
Carob (slow growing)
Goldenrain tree
Texas ebony
Sweet Acacia (thorns)
Oleander (tree form)

This is a late posting of a picture sent to me by a reader of the surface roots of an ash tree in his yard and causing damage to his foundation. His comment to me is posted in the comments section.
Readers picture of the surface route from an ash tree. This route was causing damage.

Some Mulches and Plants Bring Bark Scorpions Into Las Vegas

Q. I am hearing that some of the palms and rock are bringing in scorpions. 

Learn About Bark Scorpions and Control Here

A. It is very possible that bark scorpions are being transported here on plants and nursery materials that are coming from desert climates where bark scorpions are common. If plants and nursery materials are coming from places where bark scorpions are not common, then they are probably not going to be a problem.
          I have heard the same comment made about landscape mulches. Those mulches originating from nondesert areas most likely do not contain scorpions. That doesn’t mean they can’t be infested once they arrive here.

Check to see where your plant materials and mulches originate from. If they come from locations that do not have bark scorpions then these plants and materials are not part of the problem.

          If you have some concerns about bark scorpions then investigate your landscape in the evening hours with a black light to see if their present. Many common insecticides used to control spiders are very effective in controlling bark scorpions.
          Now is a good time of the year to make a foundation spray around the perimeter of the house to establish a barrier that these critters are less likely to cross. In the next month outdoor critters will be trying to stay warm and looking for food. Your warm house during the cool evening or night is a magnet for drawing all sorts of critters.

What to Do with Huge Sansevieria in the House

Q. We have a monster Sansevieria plant we have kept for many years.   It’s in excellent health, but threatening to take over the entire room.   It has become so big and heavy that we don’t know what to do with it now. We believe it should probably be re-potted, but an even bigger pot is going to be impossible to move. As it is, we are going to have a rough time getting it out of the house to re-pot. What suggestions might you have as to how to handle, or what to do, with this guy?  It now sits on a table in front of a west-facing window with solar screens.
Sansevieria, Snake plant or Mother in law tongue. This is a huge indoor specimen.
A. You do have a monster plant. It looks like a variety that gets fairly big but if this plant had more direct sunlight it would probably be slightly smaller. However, it's a beautiful specimen. You might have to find a place for it on the floor rather than on a table. It has nice verticality.
The choices you have are to divide it and repot it or to take leaf cuttings and start the plant all over again. As you know you can't really cut it back and still have it look good. I searched online for a video that you could watch on how to divide this plant. Dividing the plant will result in a much smaller plant in diameter but will not do much about the height unless you focus on parts of the plant that you repot that are smaller. I would suggest that you try to get it into a place with more light which should help keep it smaller.
This video should help you in figuring out how to divide it. I am sorry it is in the Czech language but the video is easy to follow without the words.
Notice how he breaks it apart with his hands. You can do that or you can take a sterilized knife and cut it apart into smaller clumps. This plant spreads underground by rhizomes or underground stems. Cutting or severing the rhizome results in separate clumps that you can repot. I would just the cut ends with a fungicide such as Thiram or just let them heal over in a safe place inside the house for about 24 hours. Then you can safely replant them without a lot of fear of disease entering the cut wounds. You can replant as many of the clumps as you want to to fill in the container. You can select the clumps that fit your need and dispose of the others or give them to a friend.
You can propagate this plant very easily with cuttings from the leaves. This video will show you how to take leaf cuttings.

Grape Leaf Skeletonizer Attacks Again!

Q. For the second year in a row, my grape plants were decimated, but starting right before ripening, and continuing throughout the summer.  I sprayed a soap spray on them, but to no avail.  I thought the problem was a slow flying black fly, but then I noticed a blue and yellow caterpillar type bug on one of the leaves.  What can I use to prevent this from happening again, and will they threaten my peach trees (not so far) Attached are a couple of photos.  The match book is for size comparison.

A. This is the grape leaf skeletonizer. Here are some posts on my blog that address this for Las Vegas.
Let me know if you have trouble seeing these.

Ants Now Invading Garden Beds

Q. We have two 4x12 garden beds made out of cinderblocks that we built last fall. We used soil from Viragrow and had great luck with the vegetables that we planted.  The eggplants and strawberries are still producing. Our back yard is just gravel so the only water is the bed irrigation. We have noticed a lot of ants on our property this summer (the tiny red ones).  They have now invaded our garden beds. I'm not sure what to do to get rid of them because i don't want to use spectricide or another harmful pesticide like that in our garden soil like I use in other areas of our property.  What should I do to get rid of them?

A. The best thing to do is to treat the nest where they're coming from. I like a product called Amdro which you can buy in nearly any nursery outlet including Lowe's or Home Depot.
This is a bait which is taken back inside the nest or it will kill the Queen. It must be kept dry and sprinkled close to the nest. Trace back to where he the ants are coming from and sprinkle a tablespoon or less around the mound that enters the underground nest.
Keep this product dry after you apply it or it will not work. It can be used in organic farm operations as long as it's not applied to the crops so it is a relatively safe product to use rather than sprays. Good luck.
Another product that works well as a spray is Prelude or products containing permethrin insecticide.
http://viragrowdelivers.blogspot.com/2014/04/prelude-insecticide-controls-numerous.html

Why Is the Bark Splitting on My Bottlebrush?

Q. Do you what is causing the bark and stems of my bottlebrush bush to split and die on the East side?  Here are a few pictures.  I don’t see any pests.  Overall, the bush is healthy (except for a few of the branches which have bark that is splitting) and it has a lot of new growth and leaves.  Only the older branches are splitting in some spots and then entire the branch dies (top to bottom). I would estimate that only about 20% of branches/limbs have bark which is splitting. The bush was planted about 4 years ago and was purchased in a 5 gallon container. I haven’t changed the water frequency or the fertilization schedule.


A. From your pictures the splitting does appear to be on the side most open and in this case the East side. To get sunburn it doesn't take that long of intense sunlight, maybe 20 or 30 minutes.
If this damage extends more than halfway around the upright stems then I would consider cutting them back. You would cut them back to remove this highly damaged area. These cuts might be quite deep inside the canopy.
That's okay because the shrub will come back and it will come back quickly to the size before. The roots will be large enough to push a lot of new growth back to its original size, then it's growth will slow down again. I would make these cuts probably around late January or February 2015.
Make sure you have enough drip emitters to provide the water that's needed. This plant does not like to be watered daily, so avoid that.
These plants tend to get yellow or iron chlorosis so I would supply either a soil application of a good iron chelate such as EDDHA or 138 iron chelate.
You can do the same thing with multiple sprays of a less expensive iron product what it might take several sprays to get much greening out of the sprays.

Fertilize after you prune this rub with an all-purpose tree and shrub fertilizer. One application a year is enough.

Palm Trunk Problem at the Base

Q. My palm trees in the back yard seem to have a problem with the trunk next to the ground.  Not sure what is wrong, too much water, bugs, I need help.  These are large palm trees and I would not like to lose them.  I have attached some photos.  I have four large palm trees with this problem.



A. This is typically not a problem for palms because there biology is different from most other trees.
Because palms are monocots a lot of this so-called wood from the outside can slough off without much of a problem. In fact what you are seeing is fairly common.
Make sure when you irrigate these plants that you keep the water away from the trunk and do not water them daily. I would be watering them about 2 to 3 feet from the trunk, not up close to the trunk. These should be watered like any other nondesert tree.


Leaf Cutter Bees Destroying Leaves on Roses

Q. We have six rose bushes in our yard in Centennial Hills that have been attacked by cutter bees. The leaves have been decimated on our rose bushes. While they don't seem to destroy the roses on the bushes, they were leaving a path of destruction on almost every single leaf on our rose bushes. We tried everything but to no avail. In fact, several "remedies" we tried, which we found online, seemed to harm the bushes and didn't even phase the bees at all. We've learned these bees are indestructible and NOTHING works to kill OR discourage them to go elsewhere!! They have somewhat subsided for now but their destructive behavior lasted for several months; from spring through early August. Our rose bushes are starting to recover but we know next spring they'll be back!! Any suggestions???

A. I have talked about these guys on my blog so I would like to direct you there.Yes, they can be destructive but there are also extremely good pollinators for our vegetable and fruit crops. Somehow we need to find a balance between their benefits for ourselves and our neighbors while minimizing or distributing some of their damage. The Leafcutter bees are gathering nesting materials for making babies.

Newly Planted Tree Shows Leaf Death and Die Back

Q. About three weeks ago I bought and planted a 12 X12 crepe myrtle tree. I used grow mulch and compost watering it once a day since then. Now the tree branches seem to be losing its leaves. Could I be over watering the tree?  What could you suggest I do to make sure the tree grows healthy? 
Small crepe Myrtle tree, Not the readers

Plant got too dry at the nursery before it was delivered
  • Plant was delivered in an open truck and the leaves were battered by the wind
  • Plant got too dry before it was put in the ground
  • Plant was put into a dry hole and the roots became desiccated or dried out for water was applied. This can happen in minutes.
  • Plant root ball fell apart when it was put into the planting holeSalt levels were too high in the soil or the planting mix or both and not leached with enough water at the time of planting
  • Watering daily after it was planted
  • Not watering often enough or with enough water after it was planted

At the time of planting, the soil in the hole, and all of its contents, should be wet. The soil should be checked to make sure that it drains several inches of water in no more than a few hours. If the soil drains adequately, the hole needs to be dug no deeper than the box.

In our desert soils with extremely low organic matter, it is best to use the soil that was dug from the hole and amend it with a planter mix amendment in a ratio of about 1:1 by volume. To help prevent transplant shock the tree should be planted as soon as humanly possible after delivery.
To help prevent transplant shock further the tree should be planted into a hole that was wet and allowed to drain. The wooden box must be removed from around the root ball at the time of planting.
This is done by leaning the tree over on its side, removing the bottom of the wooden box, pushing it back to an upright position, lowering it carefully into the hole, removing the rest of the box, and adding the backfill.
Box tree planted in the landscape. The bottom of the box is removed before placing it gently into the hole. Sides of the container is removed, the root ball is watered and the amended backfill is used to fill the hole, watering the hole as the backfill is added.

As the amended backfill soil is added to the hole, water from a hose should be running into the planting hole keeping everything inside wet. After planting, a donut shaped basin 4 inches high should be constructed around the perimeter of the planting hole.
Fill this basin twice every time you irrigate for the first two weeks after planting. Fill the basin approximately every three days. I would not rely on a drip irrigation system for delivering the water needed by the tree immediately after planting.
After 2 to 3 weeks you can begin to wean the tree from water applied by the hose and begin to integrate your drip irrigation into your watering cycle. You would do this by putting the drip irrigation on a normal schedule for landscape trees in our climate and continue to fill the basin once a week to supplement the drip irrigation and removal of any high levels of salts from the soils.
Some landscape companies leave the drip irrigation to come on daily to try and accomplish the same thing but that can be dangerous because they don't tell the homeowner to reset the clock or they forget to reset it themselves.

Three things you must regulate when you irrigate: 
how much you apply at each irrigation, 
how often the irrigation is applied and 
the time of day water is applied. 

Make sure your drip irrigation system is applying enough water every time it comes on.
It is difficult to tell you the number of minutes this equals without knowing the number of drip emitters and their gallons per hour rates of water application. The other thing needed is the size of the tree; its height and the size of its container.
How often your irrigation system delivers water depends on the time of year and the type of plant. Trees and large shrubs are watered less often than anything else in the landscape. This time of year we are beginning to cool so applying water twice a week, as long is it is enough water, will be often enough.
Time of day the application is made is the least critical feature. However, ideally the irrigation should come on just prior to the heat of the day.


Prince of Wales Juniper Low Maintenance Solid Green Groundcover