Xtremehorticulture of the Desert: 06 May 2018

Monday, May 7, 2018

Repotting Orchids

Q. My phalaenopsis orchid has outgrown its pot. I've been told not to replant while its blooming. The problem is that it has never stopped blooming. It has had blossoms continuously for two years and doesn't show any signs of stopping. What should I do?

In orchid growing in Hawaii for cutting and commercial sale

A.A crowded pot can be one of the reasons why it's blooming so frequently. Congratulations! Moving it to a larger pot may slow down it's flowering until the roots gets crowded again.Remember that these plants are epiphytes and grow on the surface of trees and deadwood in tropical climates. There flowering is timed very closely with rain. When there is rain or fog or high humidity, they flower,

I would cut off the flowers and repot it. Sounds like to me it's more about "bragging rights" than really a problem.:-) We should control the plant and have it respond us rather than the other way around. Otherwise the plant controls us

Make sure that when you repot it you don't use any soil. Crushed bark and some coconut coir is all that you need. I am guessing you have on a regular regime of spraying it with fertilizer and misting it.Keep up the good work!

Eight Year Weed Problem Identified

Q. For 8 years I have tried killing these weeds, they won't die with commercial strength weed killers. In.the last 5 years, I have hired 3 different la escape companies. Each has claimed they can kill them. No success. I finally had a landscape company remove all of my beautiful plants. Any ideas?

We problem that won't die.

A. Judging from the seed heads I saw in the picture this is common Bermudagrass. Some people call it devils grass. A single application of a weed killer will not be enough. It will laugh you.If you try to dig it up or rototill it… hahahahahaha... You have just propagated it in multiple other locations.

You can guess why to get this under control takes a lot of perseverance and repeat spraying about two weeks apart. Spray it, kill it to the soil. Let it regrow 45 inches then kill it again. You have to do this for a five times in a row to get any kind of control.

Roundup concentrate at a 2% solution (2 ounces per gallon) will kill it back. When it regrow is a few inches, kill it again to the ground. Do this over and over and you'll begin to exhaust the roots. This is the only way to get any control of this weed.

If it's growing close to plants that you are afraid be damaged, use a produt called Fusilade In the same way.

Yes, it does want to take over the earth where there is water.

Branch Die Back in Fantex Ash Tree

Q. I have three fantex ash trees. Every spring there are branches that don’t seem to bounce back from winter. They sometimes get the tufts like they are going to get leaves but never do. This winter was unusual and this year it seems I have more partial branches (my guess is last years growth portion) that have no leaves. Do I cut these off or not worry about them? My largest tree of the three could be a runner up for the game of thrones throne....ok not that spiky but worse than I’ve seen it and it’s close to being above my two-story house. REALLY don’t want to lose that tree.

No pictures submitted

A. The it's a little difficult to say without seeing what's going on but I lean towards a disease that we've had problems with an ash trees over the past 30 years in the Las Vegas Valley called ash decline. I am assuming that these leafless branches are dry and brittle.

It is a slow, progressive disease that kills more and more in the canopy year after year. The trees struggle and don't have a lot of new growth. It doesn't seem to matter what you do to the tree, once they get this disease they eventually die over time. I have tried adding more water, more fertilizer and it doesn't seem to make any difference.

Personally, I have noted that trees growing in rock landscapes seem to be coming down with this disease problem sooner than trees not going in rock landscapes. Eventually you'll have to remove it and plant something else in its place.

Ash decline

Same tree. Ash decline.

Same tree, the trunk. This ash tree was growing in a lawn.

You can look at some of my posts on ash decline

https://xtremehorticulture.blogspot.com/2018/01/dieback-of-mature-fan-tex-ash.html

https://xtremehorticulture.blogspot.com/2017/10/limbs-dying-in-20-year-old-arizona-ash.html

https://xtremehorticulture.blogspot.com/2015/06/ash-dieback-or-ash-decline-they-both.html

Selecting Trees to Reduce the Electric Bill

Q. I just stumbled by your blog and it is very informative! I am trying to get my front and backyard landscaped, and I live in the southwest area of Las Vegas. I want to add a tree in my front yard to provide shade as well as a privacy screen, since our backyard wall is pretty low. I would prefer to get a tree that doesn’t litter so much, since I live in a community that has HoA, however I’ve read that deciduous trees would be best since it will help with cooling during summer and heating my home during winter. My front yard faces west, and it has a space of 17 feet across, so a medium size tree would be ideal. So, I’m not so sure what to choose, given all this information!

A. You want to shade the wall or walls of the home, not the roof. Size depends on the height of the home. Single story homes should have trees that are below 20ft or so. At 17 ft you could get two trees on that side if they are smaller trees. Shading the West and South walls is important for energy conservation and comfort.

Plant them a distance of half their mature height from the wall. You can plant closer to the wall than this but it will take some pruning as they get larger to keep them from growing into the walls. If two trees are used then thwy can be put a little closer together than half their mature height.

Two story homes should have 35 ft. smaller trees use less water than larger trees. Personally, I like the smaller trees more since they will get shade on the house faster.

I don’t like to recommend plants so I will forward this to Andrea Meckley since she LOVES to make plant recommendations and is a Certified Horticulturist,with the American Society For Horticultural Science where I am an Associate Editor.

Join my landscape design for the desert class starting July 7, 2018. It is a multiweek class and you will finish your own personalized landscape design under my guidance and learn how to install it.

Bob Morris' landscape design class

Evergreen or deciduous is up to you. Some people like leaves on trees all year (evergreen) and some like the "seasonal" look. You mentioned low debris, so you may want to stay with an evergreen so you do not have fall leaves. For an evergreen small to medium size tree in full afternoon sun with a west exposure I suggest you look at Mastic Tree (Pistache lentiscus) (15'w x 20' h), or Xylosma (Xylosma congestum) maturing at around 15'w x 12' h. Another couple of evergreen choices are Sweet Acacia (Acicia farnesciana)a hardy tree maturing around 20' x 20' andBay Laurel (Laurel nobilis) trees also stay small maturing around 12' x 12'. For a deciduous (loses leaves in winter) tree look at Desert Willow (Chilopsis linearis) and hybrids with different color flowers maturing around 25'h x 20'w.

Plant info and pictures of trees can be found at snwa.com.

Another excellent resources to get more info on with different characteristics of plants is the 'Regional Plant List' by the Southern Nevada Regional Planning Coalition which can be found at https://wrrc.arizona.edu/sites/wrrc.arizona.edu/files/SNRPC_Regional%20Plant%20List.pdf. Very informative.

Hope this information helps. Feel free to contact me with further questions or comments.

Andrea Meckley

Certified Horticulturist

Imn2plants@aol.com

Sapsucker Damage on Australian Bottle Tree

Q. I have a 5 year old Australian bottle tree that has a large canopy. The canopy has very yellow leaves and I have found on the trunk about ¼ inch holes in the trunk. There are quite a few holes but I have not counted all of them. I don’t want to lose my tree. Can you tell me what is wrong with it?
No picture was submitted of the tree damage.

A. This is probably sapsucker damage. They are in the family of woodpeckers.They are migratory in the Las Vegas Valley and probably overwinter mostly in northern Mexico. So you see this kind of damage on preferred trees twice a year.

https://www.uaex.edu/publications/pdf/FSA-7561.pdf