Q. I read that summertime is when roses “sleep” in the desert heat. The question popped into my head a few days ago, “Can I prune my roses bushes in June and let them grow and flower through the winter months?” A. I wouldn’t. Roses don’t really “sleep” or become dormant during the summer months, but they “struggle” instead with the heat and intense sunlight. Therefore, they might stop flowering and look bad. The ideal temperature for most roses is around 65F and “comfortable growth” can range as high as 82F. Temperatures higher than this range produce increasing plant stress. Don’t Prune Roses in Summer              Intense direct sunlight causes considerable damage to previously shaded stems if roses are pruned and opened up in the summer.             Allowing intense sunlight inside the plant canopy is the major reason I wouldn’t prune roses during the summer. If you were living in Seattle or San Francisco I would tell you to go ahead and prune in the summer

Q. I have 11-year-old, 4-foot tall palm trees that are in 25- or 30-gallon pots in my backyard that get direct sunlight every day. What kind of watering cycle should they be getting during the hot summer and throughout the year? Also, what kind of nutrients should I be adding to them and how often? Even though not really a palm, sago palm or cycad makes a great container plant. A. Containers will dry out faster on the south and west sides if they are in full sun. Those sides of the container are notorious for getting super hot and killing roots. Shading the container or putting the existing container in a second, but larger container, prevents that. Note: windmill palm and pygmy date palm make great container palms! Watering Plants             Always water in the morning before it gets hot. How much and how often to apply water depends on the soil in the container. Buy an inexpensive moisture meter used for monitoring houseplants to gauge when to water again. Push the tip of the moisture meter in the soil about four inches deep. Do this in three different spots so you can get an average reading. When the average reading is near 5, water again. Inexpensive moisture sensor for houseplants does a pretty good job telling you how wet or dry the soil is. Fertilizing Plants Fertilize container plants more often than plants growing in the ground. The application frequency varies from once a month to three or four times a year. The same amount is applied over the course of a year, but the amount applied each time is split into monthly or quarterly applications. The best way to judge when an application of fertilizer is needed is using leaf color and plant growth as indicators. Plants with enough fertilizer are dark green and have strong growth.   Controlling Soil Salts             When you water, a little bit should always come out the bottom of the container. This helps remove salts that might otherwise accumulate in the soil. Apply fertilizer after every 40 waterings.

Q. My Chaste tree bloomed beautifully once in early spring but nothing since. Now it just has seeds where the blooms were. Do I need to cut the spent spikes off? This is a mature vitex tree. It can grow quite large when it gets all the water and fertilizer it wants. A. Vitex blooms once in about June. Most vitex varieties have blue flowers, but some are white and some rose colored. The flowers turn to seed. The seed germinates anywhere there is water. Some think these seed pods are unsightly. If you agree, cut them off but it is not necessary. This common vitex (blue flowers) survives in rock aka desert landscapes. Planted too close to that driveway btw. Read what Dr. Chris Martin at ASU says about this tree.             Vitex isn’t considered a desert tree (xeric) but mesic instead, is small and grows very nicely in the heat of the desert if it gets water. Make sure it gets lots of water the month prior to flowering and the flowering will be spectacular. The rest of the year water as you would any other plant in your landscape. Some people dont care for how vitex looks in the winter. BTW this tree was pruned too high.

Q. I am interested in air layering my peach tree. What time of year would it be best to do air layering? Also, would it be bad to try during the hot summer? Air layering…sometimes called marcottage…is used mostly on plants that are difficult to propagate from cuttings. Here I would put this in the interior shade of the tree and not in full sun. A. Air layering, also called marcottage, is a way of growing roots on a stem while it is still attached to the mother plant. Air layering is used frequently when plants are difficult to propagate from stem cuttings. The best time to air layer plants is the same time as planting them; spring and fall months. This video on air layering is pretty good. But I would use black plastic and not aluminum foil in the desert. And remember to sanitize your knife!             You can also propagate peach and nectarine from stem cuttings. The size that works best is pencil diameter and taken during the winter months after leaf drop. These “hardwood” cuttings grow roots best if a rooting hormone is applied soon after the cutting is made and “stuck” into a propagation medium. This is an apricot rootstock (bottom) grafted on to a Blenheim apricot. The rootstock imparts some very important characteristics on to the apricot that is lost if grown from cuttings.             When propagating peach and nectarine either by air layering or stem cuttings, the important advantage of a grafted rootstock is lost. The rootstock on peach and other stone fruits can play an important role. It can control the tree’s eventual size, how soon it starts to bear fruit, resistance to some diseases, and even affects the fruit flavor.

Q. We have been growing fruit trees in Vegas for 5 years and we want to grow about 30 to 40 fruit trees on some new property we bought. The area may have been sprayed with Roundup earlier this year. What do you recommend to neutralize or leech out the Roundup before planting the orchard? A. The science behind Roundup says it does not persist long in hot weather and in our types of soils. It has an agreed upon half-life ofless than two months and the longest half-life reported in research is six months. I don’t think you need to do anything to the soil but prepare it for planting this fall and next spring. Any remaining Roundup in the soil will be nearly gone and, at best, be negligible by then.             The USDAOrganic Program recognizes food production to be “organic” after the soil has not had any unapproved fertilizers, pesticides and soil amendments applied for the three years before and up to harvest. Since your fruit trees will not produce a substantial amount of fruit for about three years after planting, you are fine.               After three years from planting, if anything applied to the area meets the Departmentof Agriculture’s approved organic list, then anything harvested from these trees will meet the requirements for the USDA’s Organic Program.

Q. I have been living in Nevada about one year and originally from Utah. I saw that you are recommending Windmill Palm but my landscaper with 20+ years of experience was against it, recommending Mediterranean Fan Palm instead. What’s your thoughts on the two? A. Both palms do well here but they fill different roles in the landscape. The Mediterranean Fan Palm handles hot locations better, but it occupies a bigger space and is more of a visual screen when unpruned.  This is a pretty young Mediterranean fan palm. It can get much bigger than this but what is important is not only its size but you cant see through it. If you remove alot of the suckers from the base then you can see through it and reveal the furry trunk of this palm. Windmill Palm, on the other hand, doesn’t like the heat from West or South facing walls but has a single furry trunk, so it’s narrower and open so you can see on the other side of it. Both are considered accent plants, look tropical, and good around pools and water features. This is windmill palm. The fronds will get some brown tip burn but they have a single trunk and you can see around them. They fulfill two very different roles in the landscape. jSee what Dr. Chris Martin from ASU says about this palm in the desert             Where I see a problem with Mediterranean fan Palm is when homeowners try to grow and prune it like the single-trunk Windmill Palm. Why not just get a Windmill palm? The multiple furry trunks of the Mediterranean Fan Palm look nice when kept pruned annually. To me that’s just more maintenance. with some annual pruning and sucker removal you can get them to look like a multi trunk windmill palm.             There is nothing wrong with Windmill Palm and growing it here. It is a cold hardy palm taking temperatures down to 10°F. It may be a little harder to find in nurseries than Mediterranean Fan Palm and a bit more expensive. windmill palm will show some leaf tip burn when it is exposed to hot dry conditions. No doubt they do look better in more humid climates but they will grow in the Mojave Desert.             Selection depends what you want the plant to do for your landscape. If you want a palm that can handle hot locations and acts as a visual screen then get the Mediterranean Fan Palm. If you want a single trunk palm tree that requires little maintenance, get the Windmill Palm.               All palms like the soil amended at planting time and covered with wood chips, not rock. If someone tries to convince you to plant palms in sand then that’s B.S. Water palms like any other tree or shrub of a similar size and with the same frequency. 

Q. I planted the long Armenian cucumbers and they came out so big and beautiful BUT SO BITTER all through it. Why is that? Armenian cucumber is more closely related to melons than cucumber. You can identify it from its ribbing all down its sides. Harvest them when they are 12 to 15 in long. A. Armenian cucumber is USUALLY less of a problem growing them in the desert than actual cucumber varieties like Straight 8 and Marketmore. But cucumbers in general can get bitter with hot temperatures and when grown on the dry side. This is a large bag of horse bedding available from farm supply stores. You can buy small amounts from any pet store.             Try mulching the soil (apply a thin layer on top of the soil) with something like wood shavings (horse bedding comes to mind you can get from a farm supply store) or shredded newspaper to keep the soil cooler and more moist and water more often when it gets hot. The old fruit may still be bitter but new fruit should not if it works.  Here on this raised bed onions were mulched with animal bedding to conserve water. Just a thin layer was applied, enough to shade the soil from the sun.              With Armenian cucumber ,if you don’t keep the soil moist while its producing fruit, they can get bitter but it is more rare than a common cucumber.

Q. All my trees send sucker shoots up around their base. I have a drip system and water three times a week for 20 minutes. What am I doing wrong and how can I stop this sucker growth? A. It is a mixed bag. Sucker removal, and how often it’s done, depends on the plant, how old it is and how the suckers are removed.             Trees that normally grow as shrubs tend to sucker a lot. Others don’t. When oleanders are grown as multi or single trunk trees, the suckers must be removed just about all its life. Mediterranean fan palms are in the same boat. Cutting suckers off and leaving behind stubs just makes more suckers.             Some plants produce a lot or suckers when young and rain this characteristic in as they get older. Most suckers, like weed control, stop sending up more if the suckers are removed as soon as they are seen instead of waiting until they get larger. Sucker removal must be done as soon as you see them rather than wait.             How they are removed is also important. If you remove suckers when they are young you can hand pull them or rub them off with your hand or fingers. That’s easy. It’s  more work if you must get hand pruners and remove them by cutting. Not only that, but if you leave stubs behind new growth will come from those. When you leave stubs, figure three new shoots for everyone cut. If you remove suckers while they are still young you can pull them off at the point where they grow from the tree and leave no stub behind. No stub means no sucker growth.             There are sprays you can apply that decrease the suckering. They have names like “Sucker Punch”, “Sucker Stopper” but these sprays may be just a “band aid” for the problem, a temporary fix. Any time you use these follow the label direction to the letter.

Q. I intend to remove the all rock layer around my roses and apply a 3 inch layer of quality compost, dig it in carefully, and cover it with western red cedar bark. However, the rock layer is convenient for blowing out all the leaves from other plants around my roses. How do I keep the rose area clean? Roses growing in rock will start to be “unhappy” in about three to five years. A. There is a way to make your roses happier and still leave the rock in place. I understand it was convenient before because your maintenance people would come and blow away all the debris with a power blower. With cedar bark, it will blow everywhere and make it difficult for your maintenance people to keep it clean. Bark Mulch vs Woodchips             First of all, bark mulch is not as effective as woodchips for a couple of reasons. Bark moves around in strong wind and when “blowers” are used in the landscape. Woodchips “lock” into place because of their rough edges and don’t move around even if the wind speed is 60 or 70 mph!  If wind is a problem I would not use bark mulch unless you are willing to “tidy up” afterwards. Bark mulch is very attractive in landscapes but doesn’t decompose quickly and blows with any type of wind.             Secondly, bark mulch is pretty but it doesn’t improve the soil much. Woodchips disintegrate into the soil when moisture is present. In my experience, about half of it decomposes into the soil in about three years. This disintegration supplies organic matter back to the soil quickly. Woodchips don’t do that. They resist decomposition. That’s one important reason why bark comes from the outside of the tree and wood doesn’t. Keep Your Rock Mulch             Here’s how to keep your rock mulch and make your roses happier. Rake back the rock mulch 18 – 24 inches from your roses. Apply about ½ inch of good quality compost in this new area of bare soil and lightly incorporate it. Rake the rocks back and lightly water it in. Voilà! You have now added organic matter to the soil and made the roses happier. High quality compost like Soil Pro has lots of benefits including better microorganism counts and loaded with plant nutrients.             With very coarse rock mulch you can just sprinkle the compost on top of the rock and water it in. You will see improved growth from your roses in 3 to 6 months with either method. Repeat this about every two years.  Benefits of Woodchips What the roses benefit from is the decomposing woodchips and added organics to the soil. Rock (surface) mulch lets all the organics in the soil finish decomposing and your soil slowly becomes more mineralized. The organics in the soil start dwindling. As that happens, the roots of the roses finds itself in a progressively unhappy root environment. The unhappiness of the roots show up in the leaves with them yellowing, brown edges, and generally just not very productive. Woodchip mulch is made from chipping the wood inside trees. Oftentimes the only way to get it is through “tree trimmers” like First Choice Tree Service.  Don’t Forget Iron  If you still see some leaf yellowing, apply your favorite iron chelate to the soil around them once a year in late winter (late January or February in LV). If your favorite chelate doesn’t work then use the EDDHA iron chelate available from Viragrow ($20/lb) or Amazon or anyplace that sells it.  EDDHA iron chelate is effective in whatever soil you have. During mid to late summer or later you will have to spray it on the leaves.  Viragrow is cheaper! Iron chelates for leaf spraying is applied when most of the rose growth is finished for the season, like mid to late summer.

Q. This tree is approximately 15 years old. This house sat empty from 2004 until January 2020 when we purchased it. The house faces North and this tree receives full sun most days. Water during the 12 years was at best sporadic to none. I removed 95% of the plants and trees and just completed a comprehensive landscaping project. This tree was shaped and pruned by a licensed arborist. It suckers like crazy. It needs another round of sucker removal. I was not familiar with this specie and of course we moved in January and the tree had dropped all its leaves. The neighbors convinced me not to remove this tree because it was so beautiful in the summer, lots of flowers and beautiful leaves. I said yes because I did like the shape of it. What a mistake. The constant leaf and flower drop is terrible and a real challenge to pickup. In fact I made two mistakes, I planted another 24″ box size from a local nursery . It is doing the same thing. I do not use my drip system and deep water the tree every 3 weeks during the summer months. I water from the trunk out 7 feet around the entire tree. I have a lot of large surface roots due to the lack of water. I am applying about 75-100 gallons per application. The leaves are full and supple, not dry and then boom they turn yellow, get this brown scalding and dry up and drop. I have been researching and have not found a conclusive reason for this. The agricultural extension at NMSU wrote its not a matter of disease but rather a cultural practice. Soil may be to alkaline and getting to much water. According to Dr. Natalie Goldberg, NMSU Extension Plant Pathologists, “No plant pathogenic microorganism’s were isolated from submitted samples. The symptoms occur on trees well watered as well as those that receive little water.” The leaf drop starts when temperatures increase. Can you bring me up to date with your latest information about this type of leaf drop. If I can’t correct, both trees are headed for the cemetery. A. I did print nearly everything this homeowner told me he did for this tree which was a lot. I abbreviated what he told me for the newspaper. It does not sound like a lack of water. Older picture of Chitalpa in Las Vegas.             Chitalpa is regarded as somewhat drought tolerant which means you should be able to water it less often than, let’s say, a purple leaf plum and still have it look good. It is not a desert species like mesquite or palo verde, but it can handle some lack of irrigation without dropping its leaves. Limb dieback of Chitalpa from 2013.             Unfortunately, all Chitalpa trees carry a vascular plugging disease unless propagated from seed. All the named varieties like ‘Pink Dawn’ were propagated from cuttings so they will be carrying this disease as well. You can’t see this disease outwardly but one of its symptoms can be leaf drop, starting particularly when temperatures get hotter.             Unfortunately, Chitalpa infected with this disease is not a good thing to have around grapes or oleander either. The disease can be carried to either of these plants where it can kill several types of grapes like Thompson Seedless or it can stay hidden and spread from a bacterial reservoir that can be housed in oleander.             The fact your tree has leaf drop in summer is suspicious. I would remove it. Replace it with a tree you like of a size in scale with your home. Single story home use a tree with mature height of around 20 ft. Two story home, look for a tree from 20 to 35 feet tall when mature. Smaller trees always use less water. Go to SNWA plant selector website to help you find one.