Q. I am relatively new to this desert environment and I know hardly anything about desert plants.  Would you recommend the best book(s) you have read that describe these desert plants? Which are best as decorative lawn plants? When to plant them and how to care for them? A. I would focus on something written for the Las Vegas climate or secondly Tucson, Arizona and lastly the desert Southwest.             Tucson has a very similar climate to Las Vegas; a bit warmer in the winter and a bit more humid and wetter during the summer months. Tucson is in the Sonoran Desert which gets 250% more water (about ten inches of rain each year) than our Mojave Desert (four inches of rain each year) and generally has better soils.             Adjust books not specifically for the Las Vegas area to our climate and soils by recognizing that our winter low temperatures can and frequently get into the low twenties and even the upper teens on occasion. Trees you select for the “backbone” of your desert landscape should withstand these temperatures or you are asking for trouble. Play around with lesser landscape plants that don’t tolerate these temperatures but don’t expect them to survive forever.             Linn Mills from Las Vegas and Dick Post from Reno teamed up and wrote a book called the Nevada Gardeners Guide that has information split between both northern Nevada and southern Nevada. Its focus was to understand both Mojave Desert (Las Vegas) and Great Basin (Reno) conditions, soils and how to manage a landscape growing in them. Their book is available on Amazon and Abes Books if you search using the author names. It would be a good book for Pahrump, St. George and Kingman, Arizona besides Las Vegas and Reno area.             Another book I used in the past is Plants for Dry Climates written out of the Tucson area by Mary Rose Duffield and Warren Jones. As well as plants, it includes desert landscape design ideas. It is also available on Amazon and Abes Books. The newest edition includes and expanded section plant selection and care. The original version presents a concept on desert landscaping called the minioasis landscape design concept which I really like as well as landscape plants that are successful here. It applies to any of our desert climates including the Chihuahuan, Sonoran and Mojave Deserts of the Southwest but less to the Great Basin area.             A solid reference book you should have in your library is the Sunset Western Garden Book. It is not specific for the Las Vegas area but does a good job discussing desert soils, desert environments as well as an exhaustive list of plants and their descriptions suitable for many different kinds of Western environments.             As far as free websites on plants online, I reference Chris Martin’s Virtual Library of Phoenix Landscape Plants housed at Arizona State University quite a bit. Just realize its focus is Phoenix climate and soils, is 5 to 10 degrees warmer in the winter and not quite as hot in the summer. It is perfect for Laughlin, Bullhead City and Lake Havasu, Arizona as is. It is excellent for Las Vegas selections but just keep in mind the temperature limitations between Phoenix and Las Vegas. This website doesn’t pull any punches on landscape plant shortcomings and how well they perform in desert climates and soils. Once you have made a plant selection, it is a good bench check on how it will perform here.             Several knowledgeable local experts like the Southern Nevada Water Authority (SNWA) searchable database of landscape plants for Las Vegas, called “Find Plants”. It is accurate with information presented on plants but I find it somewhat cumberson to use at times. It is a good site when you are first looking for possible plants to use.

Plants have a unique way of communicating to us what they need. Learn how to understand them on this podcast of Desert Horticulture.

Lots of fruit trees are being ordered for spring planting now. These are bareroot trees, some with a known rootstock. Besides Grow Organic you have Bay Laurel to look at. They will ship early in 2020 so have your compost ready, your hole dug, a stake to keeps the roots from moving and chicken wire if there are varmits around that might want to nibble on it after its planted.

Q. When using soap and water for controlling insects, what do you use? A. I use an unscented organic castile soap used as a baby shampoo that has been certified organic by one of the certifying bodies for the USDA and its Certified Organic program.  This organic castile soap I use is available from Amazon It is relatively expensive compared with a liquid dish soap. I just figured if it is certified as organic and used as a baby shampoo it should be safe to use. I use three tablespoons of it mixed in a gallon of water as recommended by Clemson University.             Another good way is to use one of the commercial brands of insecticidal soap sprays for plants like Safers. These insecticidal soaps (yes, if it is used to kill insects it is technically an insecticide) are, hopefully, formulated with a decent soap or detergent that kills insects while keeping contaminants at a minimum and still safe for plants. For this reason, I use unscented soaps with no other additives like hand lotions.             Laundry detergents are a no-no. They are too harsh on most plants.             There is a misconception by some that these types of sprays are all around “safe” to use. We need to still treat these types of sprays with respect when using them. They are meant to kill any insect that is sprayed but once sprayed don’t stay long in the environment. Some soaps made from yucca extracts (Grow More’s EZ Wet for instance) and can be sprayed the same day as vegetables, herbs or flowers are harvested since it is also used to clean vegetables before they are sold.  EZ Wet is an yucca extract made for washing fruits and vegetables prior to selling (commercially) but can be used as a wetting agent or insecticidal soap. I get it from Viragrow in North Las Vegas, NV. These insecticidal soaps have no “residual” killing power like most traditional insecticides. For this reason, they must be sprayed more often.              Insecticidal soap sprays, the kind you buy or the kind you make, do affect plants. Most are harsh on plants like portulaca, gardenias and Easter lilies. Spray a little of your formulation on a few leaves of the infested plant to find out. Soap sprays remove some of the waxy layer on leaves while they also remove waxy layers from insects so they dry out faster. Sometimes it may suffocate them.             But soap sprays must be sprayed directly on insect pests to work well and these types of sprays do not kill only bad bugs. If good bugs are in the way, it will kill them as well.

Its all about WHEN to do things in growing vegetables in the Desert. Learn why.

Italian cypress can turn brown for several reasons; how its watered, the type of soil its planted in, spider mites during summer months and borers…yes, borers. Italian cypress Italian cypress is a tree native to Mediterranean climates along the northern coastal areas of Africa, the Middle East, Greece, Turkey, Montenegro, and southern Europe. This plant grows in climates that are cool and wet in the winter and hot and dry in the summer. In the US the describes the coastal areas of southern California. It is NOT a desert plant…but it will grow there. Selections of the tree chosen for landscapes can grow to 60 feet tall and 4 to 8 feet wide. It is propagated easily from seed but varieties like ‘Glauca’ are propagated by hardwood cuttings taken in late winter or early spring. These varieties were selected for some outstanding traits that could be marketed to residential and commercial landscapes. This is a big tree. It should not be used around single story homes or commercial buildings. Its scale is for much larger residences, resorts or commercial buildings. But many homeowners select them because they are evergreen and can provide some visual privacy, not good for noise abatement. Italian cypress can turn brown. The main reasons are the watering practices and soil type, spider mite feeding damage and borers. What? Borers? You heard it here first. Soil The soil it is planted into MUST drain water or it will die. Root rot is a common problem with this tree if it is planted in soils that have lots of clay or don’t drain water. Make sure your soil drains! Irrigation and Root Rot This tree came from climates with cool wet winters and hot dry summers so don’t water too often! Put it on a valve that waters palms, fruit trees, other landscape trees and shrubs but not with lawns, flower beds or vegetable beds. It will not like it if it is watered with the same frequency as cacti and native desert trees like palo verde and mesquite unless they are watered too often! Italian cypress with drooping branches is a sign it is getting too much water. Either it is watered too often or the soil is not draining water fast enough. Enough water should be applied each time to wet the soil to at least two to two and one half feet deep. The amount to apply varies because of the soil so you will have to play around with the number and size of the emitters. But when you apply water, it should wet the area under the canopy out to the ends of the branches. Normally I will tell people AT LEAST half the area but these trees are narrow and upright so water the entire area. Spider Mites Early stages of spider mite infestation and browning. Spider mites are always there on Italian cypress. Count on it. They become a problem when it is hot, during the summer months, and the natural mites and insects that pursue and eat them are eliminated or interfered with. This can happen right a few days or weeks after an insect spray was applied or they get dusty. The insecticide kills off the good guys so spider mite populations explode in numbers.  Or dust on the leaves and branches run interference with the good guys and block them from finding the spider mites. This is like a slow leak and their numbers don’t explode like after an insecticide application but their numbers go out of control more slowly. Mite damage is not always accompanied by webbing but it can be a hint they might be there. Use the paper test to make sure. Some mites don’t spin webs.It can be an indicator they are there but don.t rely on it 100%. Use the paper test instead. Hold a white 81/2 x 11 piece of paper near the brown area and slap the browning branch against it a few times. Don’t pick a branch that’s been dead for awhile but one that is browning or recently died. Pick one with webbing in it if you want to check it. After slapping the white paper hold it still and look for little crawlies on the paper the size of this period “.” Very small. Are the small dots moving on the paper? Do they smear on the paper if you brush your fingers against the paper? If those “periods” are moving, they smear and your plant is turning brown, it has spider mites. What To Do About Spider Mites? Wash the tree from dust after dust storms. You may need a power washer. Don’t plant them near dirt roads that allow vehicles to kick up the dirt and make them dusty. This horticultural oil can be used to control spider mites when weather is cooler. Use insecticides as a last resort. Don’t apply insecticides as insurance unless there is a good reason for the application. If mites become a problem, you may need to use a miticide, not an insecticide. I use the University of California Integrated Pest Management  websites for recommendations on borer control. http://ipm.ucanr.edu/PMG/PESTNOTES/pn7405.html http://ipm.ucanr.edu/TOOLS/PNAI/pnaicompare.php?pn=7405&x=79&y=21 http://ipm.ucanr.edu/QT/spidermitescard.html Most of the insecticide recommendations are oils (e.g. Rosemary oil, Cinnamon oil, Clove oil, etc.) and should not be applied until weather cools in the fall or spring. Borers Borers were never reported to be a problem with Italian cypress. So I didn’t suspect borers until a few years ago when it was reported to me by a homeowner. I didn’t think it was true until he sent me pictures and confirmed it. They are a problem with other cypress so it makes sense. Borer damage in Italian cypress What To Do About Borers? If borers are confirmed to be a problem use the insecticide imidacloprid as the active ingredient as a soil drench. This insecticide has been implicated in colony collapse of honeybees and its use has been banned in several countries but not currently the US. Avoid

Italian cypress can turn brown in desert landscapes. Learn why and how to prevent or cure the problem.

This podcast will teach you how to correctly select, plant and care for roses in our hot Mojave Desert climate.

Listen to this podcast so you know how to protect your tender plants from freezing temps.

October 29 There are some freezing temperatures projected by the National Weather Service for the Las Vegas Valley over the next few nights. Temperatures may drop as low as 28F in some lower parts of the valley. What makes this worse is that landscape plants are not prepared for freezing temps. They need time to prepare and progressively lower temps help them to do this. Sudden freezes are the worst and cause the most damage! Where are the Possible Problem Areas? Any lower parts of the valley where cold air has no where to drain or if it does drain, it drains slowly. Think of water. Cold air settles into low spots or pockets. But we really dont know how cold it will get. The NWS is telling you this so you have time to prepare and they usually are very cautious in their predictions. This bougainvillea froze back at the peak of its beauty Wind Makes it Worse If this cold air is combined with wind in your spot it will make it worse. Wind can channel between buildings and picks up speed in those spots. Wind removes any heat that might linger around and helps drop temperatures to freezing. Skies with good cloud cover and no wind usually don’t allow freezing temps if there is a threat. Look at the sky and cloud cover before you go to bed. Cloud filled skies mean warmer temps on the ground. Cloudless skies mean a greater chance of freezing. Plants and Plant Parts That Might Freeze Bougainvillea, a tropical plant that loves the heat of the desert, will freeze at 32F. It just does. Other tropical plants that freeze like this are tomatoes, peppers, eggplant and most of the hot weather vegetables. Plants that still have flower buds may lose them. Flower buds are very sensitive to freezing temps. They are more susceptible to freezing temps as they get closer to opening. If you have plants like Camelias that are loaded with flower buds, they may drop. Citrus too. Make a mental note which plants have flower buds. Flower bud drop due to a light freeze and damage to the edges of new leaves are signs of a light freeze. Summer Fertilizing and Freezes Never, never, never apply nitrogen fertilizers to plants that are tender after August 1. Nitrogen fertilizers push tender new growth that is more susceptible to freezes than phosphorus and potassium. This includes compost! No compost applied to freeze tender plants after July 1. The fertilizers contained in compost are slow release and last longer so stop applying them earlier in the year to tender plants. Fertilizers with anything in the first number, nitrogen, should not be applied after August 1 to winter tender perennial plants. Vegetables are fine because you will pull those to plant Fall vegetables. Protect Tender Plants Covering the plants with a freeze blanket or crop cover gives you about 5 degrees of protection. Thats all. Temperatures may get as low as 28F so freeze blankets or crop covers will work provided cold air does not get inside. So fasten them to the ground tightly to prevent wind and cold air from entering the inside. Apply them  to plants when the ground is still warm in late afternoon. Don’t wait until night because you are relying on heat from the ground to get captured under the frost blanket. Crop covers or frost blankets give you about five degrees of protection.