How Often to Water During the Heat

Q. How often should I water my trees and shrubs with all this heat. The weather got hot so quickly, I’m not sure when to water. I have a California Pepper Tree, two big palm trees and five Japanese boxwood shrubs.

California pepper tree that was planted too close to cement and so lifted it with its roots.

A. First off, don’t violate your water purveyors watering directions. These policies are in place to coordinate community water use and lower the costs of supplying water to end users like you. If you live in Las Vegas you can see it here.

            All the plants you mentioned are called “mesic” plants and require more frequent irrigation compared to (xeric) desert plants. The amount of applied water depends on the size of the plant. As plants get larger, more water is applied to a larger area (even though the water wets the same depth of soil) under the plants canopy.

Watering cacti too often can contribute to fast growth and so much succulence it cant stand up against its own weight.

            Apply water to all the area under the plants canopy. This advice might be difficult to do with larger trees like your California Pepper, so apply water to at least half the area under a plants canopy when they are big. This way they won't blow over as easily during a windstorm.

Watering frequently near the base of a plant can cause it to lose support during a windstorm.

            Lawns, annual flowerbeds and raised beds for annual vegetables require daily, or near daily, applications of water. Sometimes they need water twice a day. These plants should receive water that wets the soil to a depth of about six to 10 inches with each watering.

A piece of rebar can be used to judge how many minutes to water. Rebar pushes easily into wet soil.

            Shrubs and patio trees should be watered to a depth of 18 inches. Medium sized trees around 30 feet tall should receive enough water to wet the soil to a depth of 24 inches. Large trees need the soil wet to a depth of 36 inches after an irrigation.

            How to know if the applied water went deep enough? Use a straight, 4-foot-long steel rebar and push it into the soil after an irrigation. It stops going deeper where the water stops.

            How to water deeper with the same number of minutes? Add more drip emitters under the plant.

Hang Garlic in the Shade to Dry

Q. I recently harvested my garlic crop, wrapped it in burlap, and hung it up to dry.  How long should I let it dry in the Vegas heat? Last year I let it go for over a month and the bulbs got mushy.

Freshly harvested garlic.

A. If the bulbs got mushy then it was harvested too early or the bulbs stayed too wet. In our climate, don’t wrap garlic in burlap but dry it in the shade instead. I never had problems drying garlic. I leave the tops attached, bunch them together and hang them in the shade.

Chesnok Red garlic hanging in the shade to finish drying.

            To me, this seems a bit early to harvest garlic. My garlic was harvested in late May or June when the tops had dried back about 1/3 in the field. It is hard to tell without seeing them, but the bulbs should be fully developed when harvesting. Browning of the tops is a way to know if they are starting to mature or not. If you let the tops all turn brown then the “paper” wrapping around the bulbs will get damaged.

Polish White garlic growing in North Las Vegas.

            Garlic is planted in the Fall and harvested in early to mid-summer after the bulbs have formed. Shake the soil from the plants when you harvest, don’t wash them. I grew about 25 varieties of garlic and they all did well here. This is a good climate for garlic. So, keep an eye on the plants and harvest them when they are fully formed on their own and dry them in the shade.

My Santa Rosa Pollinator Died and I Have Pluots

Q. I have a 2-year old Flavor Supreme pluot and a four-year old Flavor King pluot. Recently my Santa Rosa plum (their pollinator) died from borers. The Flavor Supreme had only a few fruit while the Flavor King was loaded. Do I need to plant a plum tree to pollinate the Flavor Supreme? Or does it have a small number of fruit because it is only 2 years old? 

Ripe Santa Rosa plum ready for picking.

A. Flavor Supreme pluot has wonderful fruit but its production is sketchy because of spring freezes. So most likely the tree was thinned of some fruit by some late spring freezes. Plus, its only two years old! Some years Flavor Supreme may get no fruit even though it flowers because of a freeze. This is less likely to happen with Flavor King.

Flavor King pluot. Has a lot of plum in its genetics.

            Santa Rosa plum produces good soft fruit in our climate and is a good pollinator for most pluots. Flavor Supreme is a pollinator for Flavor King pluot as well. Throw Dapple Dandy pluot in that group as well. But pluots will still produce fruit without a Santa Rosa plum or pluot in your yard. Just possibly a lighter crop. If a neighbor has a Santa Rosa plum or Dapple Dandy pluot then it is to your benefit.

Flavor Supreme pluot

May is When Agaves Die

            I am getting quite a few emails about cacti dying, particularly agave. Some are guessing the culprits are ants, diseases and other readers appear to be stumped.

American Agave can die in about May of any year.

Agave Weevil

            The culprit is the agave weevil that lays its eggs at the base of agave leaves. As their young-uns hatch from the eggs, they burrow into the stem of the agave and all through it including the roots. The plant rots and dies from all the damage done usually in late April or May. We are seeing it now. A pesticide applied around its base in March, and lightly watered in, usually prevents the damage from getting worse. The other option is not to grow agave.

Agave weevils can decimate agaves in May if left unchecked

Drainage a Must

            If you’ve never grown any cacti before, make sure the soil drains easily of water and that don’t water these plants too often. I have found a deep watering every three weeks is frequent enough to push new growth and get the plants larger.

Know the Origin of Your Cactus 

Some cacti are not meant for very hot locations because they come from milder climates. Photo taken at the LV Sorings Preserve.

Some beautiful cacti and other succulents come from the hot, dry deserts of Central and North America. Make sure they are placed in full sun. Other cacti may come from milder, coastal or high-altitude desert climates and need protection from the intense Mojave Desert sun. Knowing where cacti come from empowers you and its landscape placement.

Toxic Chemicals in the Soil Cause Problems for Ornamentals

Q. I have a Mexican Bird of Paradise and ‘Sun Trumpet’ Tacoma plant growing close together. Both have deformed, dwarfed growth, and damaged leaves. The Bird of Paradise feels sticky as well. I tried sprays for insects, including Neem oil, and cut the plants down completely to have them grow back with the same issue. Other plants in the yard are doing fine. Any help is appreciated.

Herbicides applied to the soil or on a hot windy day can result in damage to the leaves and stems of plants. Sometimes plant death.

A. I don’t think these plants are facing a disease or insect problem. 

Soil Contamination Possibly

It is hard to say without guessing, but from your description it sounds like a soil contamination issue. Plant an ornamental grass and broadleaf plant in that area and see if you get the same response. If it were a cooler time of the year, I would tell you to germinate a seed mix with grasses and wildflowers in it.

Brush Killer or Soil Sterilant

            There may be a weed killer applied to this area and responsible for this problem. Some weed killers like dicamba, if applied at a heavy dose or used as a “brush killer”, can damage broadleaf plants like your Bird of Paradise and Tacoma and not hurt grasses. The high rate of this type of herbicide is why some weed killers are labeled as a “Brush Killer”. There are other weed killers sold as “Soil Sterilant” that can persist for years and kill most plants grown in that soil.

Replace Soil or Change Plants

            Some weed killers are difficult to remove by leaching with water. If the ornamental grass isn’t damaged but the broadleaf plants are, then either replace the soil in that area to a depth of about 12 inches deep or only grow ornamental grasses in that spot.

Reasons Why Meyer Lemon has Distorted Leaves

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.

Growing Peppers in Containers in the Desert

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.

Ocotillo Doesn't Need Misting After it is Established

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.

Blackberries for Southern Nevada

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. 

Butterfly Plants for the Desert

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

Twigs Dying in Ash

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.

Small Black Critters Chewing Leaf Holes

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.

Food Production - Is it Safe to Eat?

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. 

Converting Peach Tree Irrigation from Twice a Day to Normal

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.

Bay Laurel or Carolina Cherry Laurel?

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

Japanese Blueberry Growing Problems in the Desert

Q. We have three Japanese Blueberry in our yard; two in the backyard and one in the front. All three have dead branches yet there are scattered green leaves above them. There are far more green leaves at the bottom of the three plants. Is it possible this is due to a lack of water?

A. Japanese blueberry is not a good choice for a desert climate and soils but will handle it if planted in the right location, good soil prep and regular watering. If planted in a hot microclimate with alot of reflected heat and light it gets sunburn easily and dieback.

https://xtremehorticulture.blogspot.com/2015/07/more-problems-growing-japanese.html

Japanese blueberry is from Far Asia and not many deserts there so it is not really a desert plant.It grows better in a Mediterranean climate like you find in coastal CA. It grows better in a Mediterranean climate like you find in coastal CA. When grown there it is much easier to manage.

What To Do

So if the soil is covered in rock, if the water amount is not increased as the plant gets bigger then chances are good there will be problems.  Not sure what the reason is for dead branches but most likely related to soil management (not covering the soil in woodchips and not amending the soil so its more like soils in the Far East) or water or both.

Borers

It is possible to be a borer problem but I would need more information. Remove dead branches. Improve the soil and apply water to a larger area under the plant.

Orange or Yellow Bottom Palm Fronds Signal Removal Time

Q. The bottom layer of palm fronds turned an orange - yellow color almost overnight. Is this from too much water or not enough water?

Color change if the fronds of this Canary Island palm signals the owner to remove them.

A. Neither, the cause of it turning orange or yellow is natural. These orange and yellow colors are natural, masked by the strong green color that the chlorophyll provides. We see the same color changes in leaves in the fall color of trees.

            The bottom layer of fronds die a natural death. 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.

            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 would be the dominant minerals remaining if these palm fronds were used to make compost. This color change is your signal to cut and remove palm fronds.

Pruning Standard Fruit Trees to Control Height?

Q. I watched your pruning videos on YouTube and learned a lot! Is it possible to reduce the size of a standard sized apple tree to a dwarf size this way?

A. Probably not. Standard sized apple trees may grow to 35 or 40 feet in height. You might be able to keep a standard sized tree under 20 feet tall (maybe 15 feet if you’re really aggressive) through pruning but I don’t think you will get it to eight feet tall which is what I aim for in pruning semi dwarf trees for backyards. I call the size of these fruit trees “ladder less”. The standard sized apple tree is just too vigorous for pruning to short heights.

Standard Sized Apple Tree Is Big

            Standard sized apple trees normally grow 30 to 40 feet tall. Buying these trees on semi dwarfing rootstocks will keep them smaller than this but it depends on which semi dwarfing rootstock the tree has been grafted onto. I have found that the M111 semi-dwarfing apple rootstock is probably the best semi-dwarfing apple rootstock for backyards in our climate.

            Using this semi-dwarfing rootstock, I have been able to keep Pink Lady and Mutsu apples, for instance, pruned at eight feet through appropriate pruning methods. Apple trees grafted onto M111 rootstock will normally get to 80% of its mature height if left unpruned.

            Nurseries sell fruit trees with a tag that calls the tree a “semi dwarf” because most people don’t know the different kinds of semi dwarfing rootstocks. In our area an apple that is labeled as semi dwarf is most likely grafted on to M111 rootstock. 

There are online stores for fruit trees, such as Grow Organic and Bay Laurel, that specify the rootstock used and the most common semi-dwarfing rootstock available on apples for backyards in the Western US is M111.

How Much to Water?

Q.. I am writing you to find out how often should I be watering my trees and shrubs. The weather got hot so quickly that I’m really not sure when to water. I have a California Pepper Tree, 2 palm trees (a canary date and a Mediterranean fan ) and 5 Japanese boxwood shrubs.  Any help you can give me is appreciated .

A. There are two questions that need answering: how many minutes to water each time and secondly how often.

https://wateruseitwisely.com/100-ways-to-conserve/landscape-watering-guide/plant/

The number of gallons of water given to a plant depends on its size; small trees are watered 18 inches deep, medium-size trees 24 inches deep and large trees 36 inches deep.

Establishing the Number of Minutes

The number of minutes depends on the soil you have and how big the tree is. Small trees are watered 18 inches deep. Medium-size trees are watered 24 inches deep. Large trees are watered 36 inches deep. Always apply the water to wet the soil at least half of the area under the tree's canopy. Small trees are less than 20 feet tall. Medium-size trees are 20 to 35 feet tall. Large trees are above 35 feet tall.

Your soil and how big the tree is so I can tell you the number of minutes. You have to figure that out for yourself. To do that I use a 3/8 inch diameter rebar 4 feet long. If the water didn't go deep enough, water more minutes until you get there.

A 4 foot length of three-eighths inch rebar I use for measuring how deep water penetrates in the soil after an irrigation.

Right after I irrigate I push this rebar into the soil in three locations, where the soil is wet, as deep as I can. The rebar pushes in easily if the soil is wet. When the water doesn't go any deeper and the soil isn't wet anymore it's hard to push.

Watering How Many Times A Week

Each time I water I use the number of minutes it takes to get the water to that depth. That doesn't change. What changes is how many times I water each week. This is for non-desert plants.For desert plants water less often but give them the same amount of water as I mentioned above.

Winter months every 10 days or more

Starting February 1 every seven days

About mid April twice a week

About June 1 three times a week

In the wintertime I water to that depth about every 10 days or longer. About February 1 I start watering once a week. Around the middle of April I water twice a week. Around 1 June I start watering three times a week. If it gets really hot I might water four times a week. A 3 to 4 inch layer of woodchips or rock helps keep the soil wet. I only use rock with trees that come from the Southwest deserts. All the rest of the trees I use woodchips.

By the way, none of the plants you mentioned in your question are desert plants.