Q. I applied Bonide Tree and Shrub insect control for borers and miners about six weeks ago. Now my plants are growing weird and possibly dying. Once I saw this problem, I sprayed for diseases and then today for insects. What is going on? Picture not available A. The damage to the plant was probably weed killer (herbicide) damage judging from the distorted leaves and dieback. There is not much to do at this point except spray the foliage with water, irrigate, and make sure the plants were fertilized in the spring, so they are in their best health to recover as quickly as possible. Then wait and see what happens. There is no magic cure at this point except being patient for three or four weeks.             Let’s cover some reasons why this might happen so it might be prevented in the future. The damage could have originated from you or your neighbors. This type of damage is a common occurrence during the spring and the fall months because these are the most effective times to apply weed killers. Sprayer Not Rinsed             First, never use a sprayer or spray bottle that contained weed killers to spray insects or diseases. You should have two separate sprayers or bottles; one clearly marked and used for “Weed Killers”. Weed killers are extremely difficult to clean from a sprayer or spray bottle once it’s been used for that purpose. If there is some weed killer residue that remains after washing, then voilà, you just damaged plants that you sprayed for controlling insects and diseases! Spray Drift             Secondly, you or your neighbors should never spray weed killers when there is wind. If you must use a weed killer, look at the tallest trees in the neighborhood and see if their leaves are moving. If they are, do not spray weed killers. The best time to spray weed killers is early in the morning before the wind has kicked up and it starts to get warm. Heat             The word “warm” takes me to the third rule; never spray a warm surface or when air temperatures are warm or hot. Landscape rock mulch heats up quickly as soon as the sun comes up. On a warm day, these surfaces reach 150°F or more by 9 AM on a sunny spring day. When weed killers are sprayed on hot surfaces, they volatilize and move to the neighbor’s yard with the gentlest air movement and can cause plant damage.

Q. I am growing hot peppers in big plastic pots with soil for vegetables I bought from a local nursery. The plants grow fine but the blossoms dry out and fall off without setting any peppers. They get plenty of water, not too much, and the bottom of the pots are drilled out for drainage. Soil mixes like this Rejuvenate Soil Mix should have quite a bit of compost mixed in it for growing vegetables. A. Growing plants in pots is difficult in the hot desert. The major problem is overheating of the soil. The side of the container facing the sun can reach 170° F and kill half the roots inside. Losing half the roots of a plant can be quite stressful and cause flower drop. You can kill a lot of roots with a bad soil mix, poor drainage and watering too often, but it doesn’t sound like that’s what’s happening. Five gallon nursery containers are big enough if you water early in the morning and they are on the east side.  Make sure the container is large enough. Five-gallon nursery containers are large enough if plants are watered daily, sometimes twice a day when it’s hot, and the soil stays cool. I have had luck with this size container growing vegetables and herbs if on the east side of a building so the container is shaded in the afternoons. Containers may be shaded by other containers or a vegetable bed. But larger, 15-gallon containers work better. A single cabbage growing in a five gallon nursery container             Water just before the container gets hot. Moist soil is harder to heat up than drier soil. This is because the water in the soil absorbs heat. I will usually water between 7 and 9 AM.             Double pot the container. Putting the growing container inside an outer, more decorative container shades the inside container and protects plant roots. This is called “double potting” or “pot-in-pot” container growing. If the containers are the same size and shape, put a layer of pea gravel 2 inches deep in the bottom of the outside container so they don’t lodge.             Plants grown in the double containers for more than one growing season should be twisted a half turn every month to break off roots growing through the container into the ground.

Q. I have an Ocotillo plant that is now sprouting beautiful flowers and leaves. I have been watering it with a mist spray near the top. Now that it is in full foliage can I turn of the mist and just water at the base once a week? Ocotillo and myoporum went through a rough winter in 2013. This was probably January after a good freeze. A. I have never been a big fan of misting plants like Saguaro, Joshua Tree or Ocotillo. It doesn’t hurt anything, but personally I think it’s a waste of time. The effects of misting last less than 10 minutes in the desert. Ocotillo stem cuttings will grow roots in soil that drains without any misting if they are watered regularly in the spring. Ocotillo growing in the Sonoran Desert. Although not found in the Mojave Desert, Ocotillo can be found on the edge of the Sonoran and Mojave Deserts nor far from the Colorado River.             Now that the leaves are out, turn over the watering to the roots. If it is newly planted, moisten the soil each time you water close to the trunk or stem. A basin or donut constructed around the trunk helps contain the water. Fill the level basin with 1 to 2 inches of water each time you water. Remember, these are desert plants so don’t water them as often as non-desert plants. If you do, you can kill them. A good sized Ocotillo growing at a Las Vegas residence.             In about one month, increase the size of the basin or apply the water over a larger area to encourage the roots to grow further distances from the trunk. Watch the growth of your plant. Adjust your watering intervals to encourage or discourage growth.

Q. I received a Thornless Blackberry plant as a gift from an online nursery. Can I grow this blackberry bush in our yard? We have lots of rabbits and birds visiting all the time. Blackberries growing in NLV Nevada at the University Orchard. This was either Rosborough or Womack. They are very similar. A. I have grown blackberries in the Las Vegas Valley. Some varieties of blackberries perform better in the Eastern Mojave Desert than others. Some varieties struggle with poor growth and scorched leaves in our climate and soils while others don’t have the same issues. Either Rosborough or Womack at the University Orchard.             You don’t mention which variety you have, but I had success with ‘Womack’ and ‘Rosborough’ varieties out of the Texas A&M breeding program but not ‘Brazos’ which came out of the same program and was successful in Florida. I have had poor luck growing any varieties coming from the Arkansas breeding program. They mostly have Native American names like ‘Arapaho’, ‘Apache’, ‘Comanche’, etc. Rosborough or Womack blackberry at the University Orchard in NLV, Nevada. Aside Blackberries are divided into trailing, semi-erect or erect types. These blackberries were semi erect so I had a wire trellis for them mostly to keep them upright. Blackberries can also be divided into thornless or ouch. Mine were ouch! They definitely had thorns. I learned to prune them soon after harvest because it was difficult to figure out which ones had berries that year (floricanes) and which ones I needed to leave for next years production (primocanes). The canes would grow a little over five feet tall and they were flooded in a sunken irrigated bed with bubblers. After I left, the Orchard manager tried to pull them out but there were still some root remnants in there a few years after I left.             Don’t expect the same quality berry as you might get from the Pacific Northwest and they don’t keep as long in our desert heat of May. Blackberries will be ready to pick in one day rather than two or three days as they are in cooler climates. This means, like figs, you must check blackberries every day when they are close to mature.   Womack blackberry at the University Orchard probably close to May, 2004             I would grow blackberries as a novelty but don’t expect miracles. Amend the soil with good compost at planting time and water regularly.  Cooperative Extension at Arizona State University prepared an online fact sheet on blackberries from some research done in Yuma, Arizona. 

Q. I want to give my son a housewarming gift of a Butterfly Bush for his new home in Summerlin. Would there be any special care for growing that bush here? A. I think you are referring to the Butterfly Bush, Buddleia davidii. This plant is grown successfully further north, commonly in the Northeast, mid-Atlantic, and Midwestern states. It is meant to be grown in cooler, wetter climates and not intended for the desert. Will it grow here? Probably, if you plant it in the cool microclimate part of the landscape and give it some TLC.             There is another Buddleia, Buddleia marrubifolia, and called the Woolly Butterfly Bush, that does do well here and is attractive to butterflies but may be hard to find. B. davidii vs B. marrubifolia             In the desert there are better choices for attracting butterflies, if that is your intention, including Jojoba, any of the native Senna, Bottlebrush, Saltbush, Lantana, Goji or Wolfberry, Red Bird of Paradise and many others. Arizona Plant Lady on Butterfly Gardens University of Az on Butterfly Gardens

Q. Several years ago I purchased a Raywood Ash and I have been pruning off infected branches at the beginning of each season. Last week someone had a nursery suggested I apply a systemic containing imidacloprid and clothianidin as active ingredients to try to get some control. Do you know what the problem is? Cicada damage to small limbs on sweet acacia A. The problem you are seeing is most likely cicada damage from egg laying that is now healing. The female cuts a slit parallel along the top of the stem parallel to the branch with her ovipositor (egg laying machinery). The female deposits her flattened oval eggs, about an eighth of an inch long, stacked up against each other along that slit in a nice row. Cicada (probably apache cicada) on the limb of a sweet acacia in late June             If you look at the old twig damage closely, the slit looks like tiny teeth on a saw and that slit is healing nicely. When the eggs hatch a few weeks later, the babies fall to the ground and take into the soil where they feed on tree roots.             The insecticide applied as a soil drench might work because it is systemic. Another option is to apply a soil insecticide drench intended for killing grubs in the soil or eliminating the cicadas on the tree as you see them and before they have a chance to cut a slit and lay their eggs.             Continue to cut off the branches if you want if they are unsightly to you, but the tree will heal fast if it is kept healthy.

Q. For the past three years these little black critters have chewed holes in the leaves of my Mexican Primrose. What are they and how can I get rid of them permanently? Since Mexican Primrose is not a food crop, I sprayed them with Ortho’s Home Defense, but that may not be the best solution. BB sized holes in grape leaves from flea beetle feeding A. Thanks for telling me the insecticide you used but legally you are not supposed to use an insecticide unless the label states it can be used for that purpose. The active ingredient of the insecticide might work on flea beetles but unless there is a given rate of application on the label, then the rate to apply is not known. The rate of application can mean the difference between control or no control. Mexican Primrose and Flea Beetle Damage             Mexican Primrose is notorious for flea beetle damage in the spring and sometimes fall months. Knowing which flea beetle is yours is the first step in getting permanent control. If you elect to go down this path, take five or six flea beetles in a vial of alcohol to the Nevada State Department of Agriculture and ask their entomologist in Reno to identify the type of flea beetle. Once the flea beetle is properly identified, methods of permanent control can be discussed. There is quite a bit of literature on permanent control without chemicals. Flea beetles are quite small             As far as I am concerned, flea beetles are vagabonds and become a problem frequently during the spring, and sometimes fall months. Mark your calendar because they will come near the same date in the spring most years. This date signals you to start looking for them or their damage and apply the proper control measure. Heavy flea beetle damage on grape leaves             Flea beetles last about three weeks and they are gone. They can cause a lot of damage in a noticeably short time. If you see damage during the fall months, mark your calendar. Watch for holes in the leaves that signal their feeding has begun. They hide out on the bottom of leaves so you must spray “up” as well as over the top. Pesticides and Controlling Flea Beetles             Conventional insecticides used for controlling flea beetles include Sevin (active ingredient of carbaryl) or one of the pyrethrins (look for something ending in –thrin in the active ingredients). These must be applied each season you see them. Once damage is done, cut the plant back to get rid of the ugly parts, fertilize, water, and let it regrow.

Farming in the Age of COVID-19 By Renee Pinel Thanks to the COVID-19 pandemic, hand sanitizers and bleach wipes are now a part of our daily lives because everyone understands that we need access to chemicals that  kill the germs and viruses that can kill us. Yet, as things drag on, more and more weary Californians are struggling to stick with shelter-in-place orders. People are venturing out more.  We don’t see as many masks. Businesses are defying state guidelines.  People are starting to let down their guard. This is likely a combination of factors.  One, it is human nature to want to be amongst others.  Two, people are making their own calculations on their risk of exposure, based on individual circumstances.  Three, it is just plain difficult for anyone to sustain intense self-discipline over a long period of time. But we know it is possible to maintain strict standards of safety.  Look at California farmers.  For decades, they have possessed “safety-first” behaviors and practices now deeply ingrained in their DNA.  During the COVID-19 crisis, our farmers have continued to put food on the table and fill food banks while keeping their workers and communities safe.  They have achieved this not by adopting new standards of safety, but by continuing to follow existing requirements for pesticide use and safe food handling. Californians may take this for granted.  But agriculture’s emphasis on safety has been the result of a lot of work, dedication and collaboration between farmers, their communities and government.  Consider: Farmers have been able to continue to produce food because health and safety rules are the norm – not the emergency exception. California farmers have absolutely no interest in short cuts that compromise safety.  They and their families work on the farm. They value their workers. They live in the community.  Our farmers operate under the most restrictive safety standards in the country, if not the world.  Long before COVID-19 became a household word, farmers and farm businesses were investing in the safety of their employees, communities and environment. Scientists with the United State Environmental Protection Agency and California Department of Pesticide Regulation (DPR) conduct the most rigorous pesticide safety testing of anywhere else in the world – more than 300 safety reviews before a product may even be considered for use.  It takes more than seven years to register a pesticide in California. This is the same agency that regulates the sanitizers members of the public are comfortable using at levels that exceed the recommended amounts.  Just as DPR reviews sanitizers designed to kill dangerous germs, they also review products used by farmers to kill dangerous pests. Unlike the sanitizers that the public uses, DPR continues to regulate agricultural products after a purchase is made.  Farmers may only purchase and use an approved pesticide if they receive a “prescription” from state-licensed experts, who dictate terms of every use.  Agriculture follows a complex system of permitting, monitoring, inspections, and reporting to assure that products are only used as labeled. Farms provide personal protective equipment (PPE) and other safety protections to employees. Farmers, farm workers and professional pesticide advisers receive continuous education on the safe use of products. Farmers report all usage, and provide safety buffers around fields and additional precautionary buffers around sensitive sites like schools. To assure all these rules are followed, Agricultural Commissioners and DPR inspectors enforce high standards on farms and other agricultural businesses. These inspections cover the comprehensive array of federal, state, and local worker safety as well as environmental and community human health laws and regulations that cover the agricultural use of pesticide products. During this pandemic, farmers have continued to maintain these high safety standards – even around schools, which are closed.  They have not asked for any current pesticide law or regulation to be suspended or relaxed.  Neither DPR nor the Agricultural Commissioners have suspended or loosened a single regulation during the COVID-19 pandemic. Farmers continue to keep farmers markets, food banks, and grocery produce sections filled with healthy, fresh fruits and vegetables under the same strict standards as they always operate under. While those of us in towns and cities continue to live under special emergency orders that at some point will be relaxed, we can be secure in the knowledge that farmers will continue to protect their employees, communities and the consumers of their produce – long after the Governor lifts his emergency orders. 

Q. I have a well-established, prolific peach tree. About this time every year it loses some of it’s immature fruit and I know that is normal. However, this year it’s losing an abundance of fruit. I’m literally picking up 50-100 peaches a day. I have checked the irrigation and it seem to be fine with drippers at 15 minutes per day, twice a day. A. This will be a challenge. Get ready for an irrigation overhaul! The usual reason for fruit drop is because the fruit was damaged in some way, either from a lack of water to the tree or cold temperatures that hurt the fruit. I don’t think there were cold temperatures this late in the year, so I go back to the water issue. Irrigation Twice a Day I don’t like that you are applying water every day; twice a day in fact! Is there any way that can be changed to less often? That irrigation frequency sounds like watering a lawn or vegetable garden when its really hot and windy out! I don’t know about the amount you are applying, but you are applying water way too often. Peach Tree Irrigation and Woodchips  Fruit trees should have water applied to them twice a week right now and growing in most soils. The applied water should be enough so that the roots of the tree get wet to a depth of about 18 inches. For fruit trees growing in the desert, I like to see a layer of woodchips on the soil surface 3 to 4 inches deep. These woodchips provide a layer that protects the roots from getting too hot, conserves water, prevents most weeds from growing and helps keep the soil dark and rich. This is an irrigation basin around a peach tree filling with water. You are watering so often, unless you have very sandy soil, I imagine the tree roots  are growing about 2 inches deep. They should be growing 18 inches deep. Roots growing shallow like this are cycling back and forth between too dry, too hot or too wet. Roots can’t grow deeper because they are drowning (if you are watering a lot) or getting too hot and dry (if you aren’t watering enough). Thirty minutes of water is meaningless to me. I need to know how many gallons you are applying and where it’s being applied. What to do?  This is tricky because the tree roots need encouragement to grow deeper and hot weather is already here. Root growth would be better starting in October when temperatures are cooler. Do not apply any more water using the current irrigation schedule of twice a day. Free woodchips from local arborists who wanted a place to dump clean mulch. Cover all the soil under the tree’s canopy with 3 to 4 inches of woodchips. Apply water to the soil 12 inches from the tree trunk all the way to the edge of the canopy. This can be done by constructing a donut around the tree trunk 6 to 8 feet in diameter. Basin beneath grapes that didn’t hold the water. It was repaired but easy to see! The inside of this donut must be flat with a circular wall that is 3 to 4 inches tall. Fill the inside of this donut with a 1-inch layer of compost with woodchips on top. Fill the inside of this donut with water once a day. At the end of August, begin watering every other day. At the end of September water every third day. By December you should be watering once a week. Rectangular basins with flat insides to hold water but let people and equipment through. I generally figure that most peach trees that produce an abundance of fruit should only be allowed to keep about 1% or less of all the fruit produced by a tree. I’m assuming you are removing fruit that are closer than three or 4 inches apart all through the tree. When peaches are pruned in the wintertime about half of all their branches are removed from the limbs. The removal of these branches are so that the remaining branches produces fewer fruit and there is less thinning to do. Otherwise there’s a lot of limb breakage because of the weight of the peach fruit.

Q. I found your blog and am hoping you can tell me if this tree in the picture is a Bay Laurel. I have looked at pictures of Carolina Cherry trees that also 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. 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.             One easy way to tell the difference is to crush the leaves and smell the herbal (Bay) aroma of Bay Laurel. Bay Laurel leaves are pungent in their aroma. When you crush the leaves of Carolina Cherry Laurel they have an aroma of cherry rather than herbal.              The second way is to look for round “glands” at the base of the Carolina Cherry Laurel leaf where the leaf is attached to the petiole (leaf stem). These “glands” are characteristic of many plants in this genus (Prunus). Click here to see the glands on P. serrulata