Q. Is there a simple way of stopping or preventing the volunteer trees, i.e., new tree growth that suddenly starts growing near the base of original tree?  Root suckers can pop up at any distance from the tree. They can be used for propagation but remember, as in this case, the suckers are clonse of the rootstock and not necessarily the tree on top (scion). A. Some plants grow “suckers” at the  base of the plant and others produce suckers, or new growth, a distance away from the plant.  If roots of suckering plants find water and it is out in the open with enough sun, they will sucker.  Oleander suckering from its base (crown). This is the difference between suckers arising from the stem or trunk (sometimes called the “crown”) and growing from the roots. Plants that can grow as a bush sucker from the crown. Plants that forms “thickets” grow suckers from their roots. Roots suckers are common to some plums and jujube as well as landscape trees like elm. Jujube suckering several feet away from its trunk. Several trees have root suckers like Jujube when they must survive fires.            So far, the only practical way to eliminate them is to slice the roots and remove these plants, roots and all. To prevent diseases found in the soil from invading the tree roots, allow these cut surfaces to heal 24 hours before burying them again.

This list was previously put on my blog years ago and I have been asked about updates. The varieties listed here were tested in North Las Vegas with at least five trees per variety for at least 5 years before they were given a rating and the “green light” for planting. Some didn’t make it, either because of winter cold temperatures (citrus, Mexican nopal cactus), possible low humidity problems (sweet cherries and ‘Hachiya’ persimmon) summer high temperatures (filberts, rhubarb), and poor growing conditions (filberts, rhubarb, blueberries, some blackberries, raspberries).  Just because they didn’t make it in North Las Vegas, try it in your microclimate. They might work and please let me know. Give them at least three growing seasons (preferably 5) before you claim a winner.   Citrus does grow in Las Vegas. It just depends on the microclimate of where its growing. I would like to thank Dave Wilson Nursery (particularly Tom Spellman and Ed Laivo (formerly at Dave Wilson and now at Burchell Nursery) for supporting this project. About 95% of the fruit trees planted were donated. I would also like to thank Tony Valenti , Owner of First Choice Tree Service for believing in my project enough to donate woodchips to use as a soil mulch when local tree companies were against it. They donate woodchips to the University Orchard still in 2020. which is then donated to the community through the Community Mulch Pile. Community Mulch Pile at the University Orchard in North Las Vegas. There is a second community mulch pile located south of McCarren Intl. Airport. Call 702-257-5555 during the week and get the details. What is a Microclimate? Microclimates in landscapes can have different temperatures during the summer or winter (hot walls, shade, freezing temps), humidity (lawn, pool, fountain), sunlight (reflected glass), differences in wind (channeling between buildings) and all these affect plant performance in the desert. Plants do best when everything is still, plenty of sun (but not too much), temperatures warm, and humidity moist. Citrus Citrus include kumquat, lemons, limes, oranges, grapefruit and others. By now you should know that kumquat is probably the most cold hardy of the group, followed by Myers Lemon, Grapefruit, and others. Citrus is not included here because we lost the citrus to low winter temperatures (below freezing weather) before the five years was up. However, in some locations around Las Vegas citrus was thriving. At another location, the same thing happened or they were heavily damaged by the winter cold. So be careful planting citrus here. The second problem with some citrus are January, February and other late spring freezes. These freezes eliminate some or all of the fruit coming from citrus flowering then. Low Humidity Another characteristic of the Mojave Desert is its low humidity. Very low humidity. This is a problem for some fruit trees. Sweet cherries and ‘Hachiya’ persimmon also were not listed, because they seldom produced much fruit unless there were spring rains. Yet in some locations in Las Vegas sweet cherries produced every year! I think it was because of the low humidity. Residences with lawns or a swimming pool close by produced fruit. Some tropical species also have problems with fruit set at a humidity lower than 30%. It is believed to happen because of the drying of pollen. Go to my fruit tree list (former blog post) Request a copy of my list (email)

This is the current (2020) production coming from peaches and apricots at The Orchard at Ahern. The Orchard at Ahern is located between Bonanza and Washington off of Clarkway. There are about 3000 fruit trees planted in this 8 acre orchard only 1 1/2 miles from the Las Vegas Strip. The Orchard at Ahern is a 3000 fruit tree orchard located on Ahern property only 1 1/2 miles from the Las Vegas Strip. Apricots pruned for height control spaced at 10 ft between trees and either 10 ft between rows or 14 ft for equipment movement. Apricot production. Apricots and aprium varieties totaled about ten different varieties with chill ranging from a little over 200 hours to over 700 hours and no fruit thinning. Apricot and aprium varieties include Flavor Delight, Leah Cot, Summer Delight, Katy, Chinese, Royal Rosa, Blenheim, Flavor Giant, Gold Kist among others on semi dwarfing Citation (preferred) and Myro 29C. Peaches were on the same tree spacing as apricots and pruned to the same height. Peaches were thinned by pruning when they were dormant during the winter. No hand thinning of individual fruit was done. About 24 varieties of peaches and six varieties of nectarines were planted about four years ago. Again our favorite rootstock when keeping them under ten feet tall is Citation semi dwarfing rootstock.

Q. We Live in the Phoenix, Arizona area and have two 10’x10′ planters made of pavers and want to plant ‘Red Push’ Chinese Pistache in them. I am worried about damage to pavers from the roots. Irrigation would be from drip irrigation system on a timer. One of the planters for a Chinese Pistache tree A. ‘Red Push’ Chinese Pistache tree can get 50 to 60 feet tall with irrigation. In my opinion, this tree is too tall for most residential properties. You need a large landscape, a park or city streetscape to accommodate that size. Read what Chris Martin from ASU has to say about Chinese Pistache in the Phoenix area. The size of the planters should not be a problem when planting Chinese Pistache if using a soil coarse textured enough for good drainage and not planting shallow rooted flowers in there that require frequent, light irrigation. If planting something else in that planter, select plants that have deep roots or that don’t require frequent irrigation. I would select a smaller tree. I have the feeling you selected that tree because of its fall color. There are other reasons for tree selection than just one trait. What sizea tree is needed for those planters? 20 feet? 30 feet? Remember, larger trees usually use more water. What shape should it be? Arching? Round? Upright? The Phoenix area has some pretty good wholesale nurseries that grow plants for the desert including Mountain States Nursery and Arid Zone Trees. Take a look at what they have to offer.

Thinning fruit, or fruit removal so the remaining fruit become larger, does not have to be a mystery. It is a management process that you must do for most fruit trees. If you don’t, the remaining fruit will not become larger. But on some fruit trees it doesn’t work. Learn which ones it doesn’t work on and why in this Desert Horticulture Podcast.

Learn why Bottle trees are NOT desert trees, managing spider mites in home landscapes and the reasons for the yellowing of plants growing in desert soils.

Our light intensity is very strong in the desert. Some thin barked trees and shrubs get sunburned if they don’t have enough protection from strong sunlight. The natural way to protect plants from sunburn is to allow these plants to shade their own trunks and stems with leaves. Not providing enough water can thin out the canopy of trees and shrubs and encourage sunburn. Sunburn, like on this ash tree, starts out as a discoloration of the wood. Plants that typically sunburn include many of our fruit trees, mostly peach and apples. Ornamental trees and shrubs also get sunburn. Plants that I see with sunburn include Japanese blueberry, locust trees, ash trees, Indian Hawthorn, and others. Sunburn can happen to fruit, too. This yellow apple has the first sign of sunburn on the fruit facing the sun. Severe sunburn causes the plant to die on the side exposed to the sun. Bark on this side is loosely attached to the trunk. When you pull this bark away from the trunk you may see oval-shaped holes in the wood. These are exit holes of borers. Removing the bark also removes hiding places and birds have a better chance picking them off when they emerge. The side facing the sun dies under severe conditions and boring insects can invade the living parts on the edges of the damage. Eventually this becomes part of the tree that dies. Having rock mulch around plants that do not like rock mulch reduces the number of leaves and increases the chance of sunburn. Plants that do not like rock mulch, like the ones I mentioned above, will develop an open canopy, leaf loss, and sunburn. In the case of sunburned fruit the area darkens as the sunburn worsens. What’s the problem with sunburn? When humans get sunburn we recover. When plants get sunburn, particularly in a desert climate, they frequently decline and die. Attack by boring insects, or borers, is the first phase after sunburn damage. The borers create more leaf loss which increases sunburn. At this point the plant falls into a death spiral. The side of the branch or trunk facing the sun has the most damage. In this Bottle tree it is the upper surface of the limbs. Use surface mulch, particularly wood chips, and not bark mulch. Don’t water trees and shrubs daily. Water them two or three times each week during the heat of the summer. Reduce the number of times per week during the cooler months. When they receive water, it should water the roots to a depth of at least 12 and preferably 18 inches.

As I was walking my property, I was thinking about landscape maintenance contractors and what they should be doing when going from job to job. As I thought about it more, I realized it would be a good message to homeowners as well. Alcohol wipes are safe and easy way to sanitize pruners. Sanitize Pruning Equipment Tree and plant diseases like Sooty Canker and Fireblight and, who knows even though its not proven, Ash Decline. We know that many plant diseases are passed along from plant to plant and residence to residence by unsanitary equipment, hands and clothing. Sanitize your pruning equipment between residences. If you see a plant or tree that you are trimming and it doesn’t look right, SANITIZE any pruning equipment you use on it. Then educate your customer. Let them know you are doing it and why. Make it a difference between your company and another who doesn’t know or, worse yet, doesn’t care! BTW, most tree diseases are spread when the tree is actively growing so a good time to prune is during the winter months. ALWAYS sanitize your tools when plants are growing. Sanitize Mowers Besides lawn diseases, lawn weeds can be passed on from property to property on unclean mowers. Everyone is using a mulching mower now but they still need to be cleaned, particularly when a disease is active. Our lawn diseases are mostly “hot weather diseases” like Summer Blight. Many of our worst weeds I hear complaints about are “winter weeds” like Poa annua. Spreading lawn diseases and weeds lasts 12 months long. Ask to use your customers hose and wash mowers between jobs, Turn the mower over and spray the blade with a sanitizer before the next job. Handling Your Boss More money is a good incentive. Instead of being the “tree hugger” or “plant person” on a job, use the money angle. Charge a little more for the work you do. Or tell them it will reduce costs. It costs a bit more to sanitize your tools and equipment but your customers will pay for it. As I always tell my students, “Pursue the HIGHEST dollar you can get, not the LOWEST!” Charge for your time and let the customer know you are doing something about the spread of plant diseases and weeds.

Q. I found your blog, Xtremehorticulture of the Desert, and hoping you can tell me if my tree is a Bay Laurel or not. I looked at pictures of Carolina Cherry trees that look similar. This tree has supports which I know need to be removed at some point. The tree was planted by my builder in February of last year. Bay Laurel just after we pruned it A. Looks like Bay Laurel to me. Bay Laurel is a Mediterranean tree and more tolerant of our desert climate than Carolina Cherry Laurel. Carolina Cherry Laurel is native to the southeastern US and not tolerant of desert conditions without proper site selection, soil preparation and watering. Carolina cherry laurel is native to the SE United States so it struggles when planted in hot locations with inhospitable soil. This one is suffering from iron chlorosis.             One easy way to tell the difference is to crush the leaves and smell the herbal (Bay) aroma.  Bay Laurel leaves have a pungent aroma. When you crush the leaves of Carolina Cherry Laurel they have an aroma of maraschino cherries rather than herbal.             The second way is to look for round “glands” at the base of the Carolina CherryLaurel leaf where the leaf is attached to the petiole (leaf stem). These “glands” are characteristic of many plants in its genus (Prunus) like plums, cherry, peach, etc.             In 98% of the cases, the “supports” or stakes should be removed after one growing season. There are a few cases when the trees do not establish rapidly due to grower mismanagement or poor planting practices and need support longer than this.

Q. The bottom layer of my palm fronds turned an orange – yellow color almost overnight. Is this from too much water or not enough water? Palm fronds may turn orange before they become yellow or brown and then die. Its your signal to prune. A. Neither. The cause of these fronds turning orange or yellow is natural. These orange and yellow colors are already there, masked by the strong green color that the chlorophyll provides. We see the same color changes with “Fall color”. Canary Island Date Palm with lower fronds dying naturally.             The bottom layer of fronds die naturally. As these lower fronds approach death due to old age and shade, some of the minerals in the leaves are absorbed back into the palm, first turning the lower fronds orange or yellow and eventually brown. Sometimes these color changes occur quickly and other times more slowly. How fast depends on how hot it is. Fan palm with brown lower fronds in need of pruning and removal.             The nitrogen, phosphorus and potassium move out of the frond first followed by magnesium, chlorine, zinc and molybdenum. Lesser mobile nutrients are left behind which include sulfur, iron, boron, and copper. These mineral “remainers” dominate the content of palm fronds. This color change is your signal to cut and remove palm fronds.