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Sunday, August 1, 2021

Plants for Privacy from Neighbors

I have had many complaints about using plants like Japanese blueberry, Carolina cherry laurel, or Bay Laurel for a privacy hedge. I decided to create my own list. Hedges for privacy are usually evergreen or will hold their leaves as long as possible through the winter. You may have to order them online if not available locally.

Carolina cherry laurel with water stress.

Good to 25F or Less and Full Sun

These evergreen  or mostly evergreen plants can be planted in full sun and away from other plants. These plants will survive winter cold temperatures to at least 20F and high temperatures over 120F. They will need it if they are surrounded by rock, exposed, and in full sun.

How Tall?

Judge how tall you need your privacy hedge. Use smaller plants when possible. Larger plants need more water as they get larger. If planted in a row, use drip tubing. Spacing for a hedge should be 1/3 of their mature height. Most can be sheared with a hedge shears to increase their privacy factor. Mesic plants can use more water than xeric plants but it depends how you water them.

Mesic vs. Xeric

Xeric or desert plants can handle less frequent watering. Mesic or nondesert plants should be watered with other landscape trees and shrubs. Xeric plants should be watered with other xeric plants. Use drip tubing or bubbler/basins rather than individual drip emitters. 

How to Plant?

Plant in the fall or spring. Plant them as you would other landscape plants; with compost and a pre-plant fertilizer. Surround them with rock mulch or woodchips. Your choice. Fertilize them once in the early spring each year. Stake them only for one year after planting. 

How to Prune?

Pruning may be necessary once every five to ten years. Prune them to the ground and let them regrow from their roots.

Under ten feet

5 to 8 feet        Cape Honeysuckle. Can freeze in winters. Evergreen and showy.

3 to 10 feet      Jojoba. Water controls growth. Xeric. Evergreen. Tough.

8 to 10 feet     'Green Cloud' or 'Silver Cloud' Texas Ranger. Not evergreen but they are dense enough to provide some privacy in the winter. Make sure it is the correct variety and not a dwarf type. Xeric. Will grow back slowly. Tough.

Over ten feet

10 to 15 feet    Red or white flowered standard Oleander. Evergreen and can handle low winter temperatures and stay green. Mesic. Tough.

10 to 15 feet    Little leaf Cordia. Hard to find but evergreen but can be deciduous when it freezes hard. Xeric. Tough.

10 to 15 feet    Texas Mahogany. Purple flowers in the spring. Evergreen. Genista moth in the spring can chew leaves. Xeric. Tough.

10 to 15 feet     Hopseed Bush. Requires well drained soil. Xeric. Tough.

8 to15 feet        Cassia aka Senna. Many different kinds. Mesic. Tough.

Over 15 feet

15 to 20 feet    Lady Banks Rose. Can get large. During winter freeze it can become deciduous. Mesic.

Over 20 feet

25 - 30 feet      'Swan Hill' or 'Wilsonii' European Olive. Evergreen and must be pruned to a bush form for privacy. Mesic. Some fruit produced when it is older. Tough.

Adding Cacti to Your Landscape

 Not all cacti are the same. Remember that. Just because its a cactus, or looks like a cactus, does not mean they can go out in very hot locations. Some can and some can't. Mojave Desert cacti. Most of these are cholla, hedgehog, beavertail (Opuntia), barrel cactus, some of the yuccas, and others. They can handle the heat from a southern or western exposure in the landscape. As well as a few of the cacti types not from the Mojave Desert but from the Sonoran (ocotillo, and Chihuahuan (Nolina, Dasilyrion, Ehphorbia, and some Agave) 

Most of the opuntia type cacti come from the dry regions of Central America; the Sonoran and Chihuahuan Deserts.

But when it comes to other cacti from other places, watch out! They may not be able to handle a south or west exposure all alone. Some of these cacti to be careful include the silver or red torch cactus or the Peruvian apple cactus. or even our native Spanish dagger yucca.

Low Winter Temperature

Some Sonoran cacti like the Blue agave used for making tequila is hardy to about 25F. When temperatures approach 25F or drop below it, as it often times does in the Mojave Desert, it will be damaged. There is a compromise. The Blue Glow agave found at higher elevations (around 4500 ft) is good down to about 15F (safe to grow in the Mojave) but not as hardy at temperatures above 100F. So it is best to grow this cacti with some afternoon shade. 

Be careful where you get your opuntias or beavertail cacti. If they come from the warmer Sonoran desert then they might not handle the lower temperatures of the Mojave.

Win
Freeze damage to beavertail cactus (Opuntia) from the Sonoran desert when grown in Las Vegas
 and winter temperatures drop below freezing.

Sun Damage to Cacti

You would think a "cactus" type plant would be good in a hot dry location. 

Plants like the Gloriosa yucca (Spanish dagger) even though they are a yucca, are not good for hot locations in the desert. It can fool you. They are good as a native in the Southeast but not the Mojave. It is mesic needs rainfall and protection from the hot desert sun. Yes, they are sold in Las Vegas nurseries. Dont get it confused with yucca and cacti that are for dry areas in full sun (watered once a month like soaptree yucca, Nolina, ocotillo) and desert spots watered quarterly (cholla, most opuntia, barrel cacti, ferro cactus).

Bottom line, just because its a cactus, doesn't mean you can put it in anywhere you want. Some need a little bit of shade (Peruvian apple cactus, Silver or Red Torch) Some need winter protection (Blue agave, Sonoran opuntia), Know your cacti. Dont mix and match. Know your cacti. Know your cacti 2 and cross reference your list.

Almonds for Backyards in the Mojave Desert

Probably the two varieties I would chose for almond production in backyards are 'Garden Prince' and 'All-in-One'

Almonds are some of the first fruit trees to bloom in the spring. Traditionally almonds have a white flower but the 'Garden Prince' variety has a purple hue to its color.

The nuts taste the same in my opinion (they are both sweet almonds), not the same flavors you can get from other parts of the world which focus on nut production and flavor. But both 'Garden Prince' and 'All in One' varieties stay small. There is a marketing push right now more for planting 'All-in-One' than 'Garden Prince'. Not sure of the reason but I suspect it has to do with MONEY. Just a hunch :-).

 Probably if I were to get a standard sized almond I would get 'Nonpariel' and keep it smaller through heavy pruning each winter.

Fresh market in Khujand, Tajikistan, with all the different types of nuts available. Here the different types of almonds ranged from sweet to bitter with many different types of flavors.

Almonds in the US are focused on the sweet types of almonds. Bitter almonds are ignored due to taste preferences. 


Almond selections from a major wholesale almond grower in the US.


Some of these bitter types are "dual purpose" and the fruit can be used (resembling apricots) and the nut can be consumed. Reminds me of the days at the University Orchard in North Las Vegas when I just could not get all of our almonds shelled for fresh market. So I made the decision to market them with their husks still attached....yes, the fruit. We sold it as a novelty item at reduced prices (which in actuality resulted in better profits due to no labor involved and the "oddity" of fresh almonds sold in their dried fruit (husk). People did could not believe they were almonds and bought them out of curiosity to "show their kids". 

Some almond trees can get big (up to 30 feet tall) while others remain smaller from semi-dwarfing rootstocks or by breeding. Contrary to some information on the web, the most popular dwarf and semi-dwarf almonds ('All-in-One' and 'Garden Prince') are due to plant breeding and not rootstocks. So for backyard production the smaller dwarf and semi-dwarf types are preferred.

Another picture of the market in Khujand and the varied selection of almonds, both sweet and bitter as well as dried grapes (raisins), yes, even the famous Afghan variety, 'Kismet'. Kismet is taken from the Persian word as well as the grape.

Planting of Almonds

Plant in the spring or fall months when it is cooler. Ignore the temptation to plant when it is hot. I have had luck planting as early as the end of January (early peaches will start to flower the first week of February and later varieties throughout the month). The hole is pre-dug the day before purchasing the tree so that it is AT LEAST  three times the width of any container it might come in (digging deep is not necessary unless there is a drainage problem). If it is bareroot, then make sure the hole three foot in diameter. 

Desert soil low in organics needed by nearly all plants. So add organics or compost to enrich the soil at the time of planting.

Desert soils are usually low in organics so if the color of the soil is light brown to tan then add one shovel full of organics, such as compost, together with three shovelfuls of the soil taken from the hole. If this advice is ignored then use a pre-plant soil mix such as Viragrow's Garden Soil Mix. If a rich soil mix like Viragrow's is used, no pre-plant fertilizer (high in the middle number, phosphorus) is needed. High quality compost is all inclusive and high in phosphorus. No additional fertilizer is needed. But if you create your own soil mix or plant without it then mix with it either bone meal or MAP fertilizer at the time of planting. Use lots of water when planting and stake the tree before trusting your irrigation system.

Growth of Almond Trees

Sometimes almond trees grow slowly, die or dieback after planting. This is not what should happen!

Sometimes almonds are planted too deep or any surface mulch  can cause problems with young trees.

Check to make sure it was planted at the correct depth or that woodchip mulch has caused the trunk some problems. Pull all mulch away from small trees about a foot after planting and keep it there!

Pests of Almonds

Pests of almonds in southern Nevada arent nearly as involved as they are in almond (pronounced regionally as a' mund without the "L" sound) production areas of California. Primarily it is due to our isolation from that growing region.

Aphids on almonds. Aphids like to hit up fruit trees from their overwintering locations oftentimes at the base of trees. That's one of the reasons why dormant oil applications can be so terribly important on fruit trees in particular.


Sapsucker (woodpecker) damage on 'Neplus Ultra' Almond in North Las Vegas


Probably root weevil damage on the leaves of almond. Not sure 100% since they come out at night to feed. It can be seen on ornamental trees and shrubs as well.


Ground squirrels can harvest the nuts from the tree overnight. They do this by cracking open the husk and shell and taking the nut.


Sometimes we see some squiggly sap coming from the nuts when they are immature. This can be from feeding damage by insects with piercing-sucking mouthparts (like the leaffooted plant bug or stinkbugs which are quite common in the spring or even diseases.


This feeding on young almonds results in what are called 'Blanks' or almonds that are empty of a nut. This shriveled nut can be left inside the otherwise empty husk and shell.

It takes about three years before you start harvesting the nuts from the trees if all goes well.

Almond Nuts Dry and Hard. Why?

Q. I have a 10 yr. old ‘All-in-One’ almond tree that is healthy and produces an abundance of nuts.  Most of the nuts are not edible because they are dry and hard.  Is this due to the desert conditions here? I have tried picking at different times, boiling and roasting them.  Any suggestions?


Feeding by insects, and sometimes even disease, can cause almonds to not produce a nut.


A. 'All in One' is a good variety of almond for this climate. It is a self-pollinating, semi-dwarf variety introduced from Zaiger Genetics and marketed by Dave Wilson Nursery with good nut production here. Great for a backyard. Although I have to admit I like 'Garden Prince' almond (another almond introduced by Zaiger Genetics) more because of its flower color. The flavor of the nut is the same in my opinion. You can't go wrong with either semi-dwarf tree for backyards.

Something is wrong. Check for damage to the nuts from insects like the leaf footed plant bug. The mama insect can fly in from your neighbors yard around the end of March or early April and start raising her young. It doesn’t take long and she and her brood start feeding by sucking the life out of the nuts as they are developing. This causes the nut to abort leaving a husk that shrivels and dies.

Leaf footed plant bugs require weekly hand picking, a cordless vacuum cleaner or a one-time pesticide application to kill or remove them.

You say you are checking the nuts as they develop but start splitting the husks open in about late March or April. Check the nut development inside the husk and look for these bugs causing damage at the same time. They are normally harvested in Las Vegas in July or August.

Silver Torch Cactus Stems (Columns) Shrinking

Q. I have a clump of silver torch cactus about 7 years old and some of the columns appear to be shrinking in diameter. It appears to me that the smallest column is narrowing in diameter about 4 inches above the soil line.  The largest one also appears to be narrowing at the bottom as well. I don’t water from November through February and start watering again in March and April and September and October and fertilize twice a year with a cactus fertilizer. In the summer months of May through August I water twice a month. There are no soft spots near the ground and no pests I can see. What do you think?

Silver Torch cactus. A beautiful cactus from the high elevations of Argentinia and Bolivia.
 THEREFORE it does not like high temperatures of our Mojave Desert. Protect it from high light intensities of the late afternoon...that means dont plant it on the West or South side of a home.

A. This is a clumping cactus that grows to about four feet and can handle winter temperatures to about 20F. It also likes high intense sunlight but cooler temperatures than ours in the summer. For that reason, it performs better if it does not get intense heat during the hottest time of the day in the summer. Make sure it gets some shade if it is on the west side. Also, I would give it one more irrigation during the cooler months but your timing of irrigations look good when its hot and the soil does not stay wet. Don’t water more often than that. 

Silver torch cactus is from the dry higher elevations of Bolivia and Argentina and not from one of our deserts. It struggles during our hot summers starting in the low 100’s and particularly in hot locations (such as a western or southern exposure in full sun during June - August). It is not from the Mojave Desert! Surrounded by rock in these locations make it even hotter! So be careful when using this plant and plant it in the correct location!

Want info from Tucson on this plant?

            Many cacti have narrower stems at the bottom as they get older. Older stems get “woody” at their base and cant expand and contract as they store and use water. They also develop constrictions along the length of long stems when their growth ends. Constrictions along the stems make convenient places to propagate them. Just make sure you sanitize hand shears when cutting! If you are checked for soil drainage and root rot, then I don’t think their narrowing is a problem.

Strong Winds Damage Bottletree and What to Do

Q. I have several bottle trees, now over 7 feet tall, damaged by two windstorms close together. After the windstorms, the branches were sagging, and the tree looked pitiful; the tree looked like it was in shock. Next morning I watered it thoroughly for about 5 minutes with a hose. The tree looked happier. The trees are watered twice each day for eight minutes by drippers and surrounded by rock mulch.

Bottletree loss of leaves due to high winds. Make sure when you water these trees that they are given enough water, maybe 20 to 30 gallons depending on their size, and distributed over a wide area. Then hold off on your next irrigation until the soil has a chance to dry out. This helps the roots of the tree to breathe and not get suffocated by the water.


A. I’m not a big fan of watering daily and watering trees for only a few minutes each time. Basically you give them a sip of water every day instead of a big gulp all at once. I understand that some irrigation systems will allow different irrigation scenarios. Now is the time to bite the bullet and change all that.

Put trees and shrubs on different irrigation lines from the much small plants that must be watered daily. Please realize that as trees get bigger they need more water, and they need this water applied to a wider area. This means adding more drip emitters under the tree every three or four years as large trees and shrubs get bigger.


            Tree roots grow where water is applied. If water is applied close to the trunk, that’s where roots will grow unless there are other plants nearby also getting water. Roots growing close to the trunk (because that’s where all the water is!) increase the chance of the tree blowing over in a strong wind. They must survive on the water that you give them and where it’s applied. Where water is applied is where plant roots will take up the water. They know enough NOT to take water up from dry soil. They can't! This is why partial root zone drying works. Its science you truthsayers.

How to give it more water without changing the time on the irrigation clock?

            What to do? Add more emitters under the tree canopy about 18 inches apart. Spread them apart. Apply water to a larger area under the tree canopy. And water for a long time. Add these emitters to previously dry areas further away from the trunk. Instead of watering twice a day, water every other day, only once, but water for 30 or 40 minutes instead. Pretend you are filling a reservoir of water and let the tree use half of it, then water again and fill it.

Rebar and how deep to water? Pretty easy and cheap to do. Push it into the soil into the wetted soil several spots just after an irrigation. 

Want to Know How Much to Water?

Want to know how much to water? Buy a thin piece of rebar about 4 feet long and push it into the soil after you finish an irrigation. The rebar slides easily into the wet soil where water is applied and then it stops. If it stops at 15 inches deep and you want 18 inches, add another ten minutes to your irrigation to get it deeper or change to a larger emitter. 

Dont want to add more minutes to the clock? Add more drip emitters and increase their size if needed. Put them 18 inches apart and let them fill the soil to the proper depth. Remember with trees, it is important to water deeply AND apply it wide enough under its canopy. This is what is meant when people say, "Water trees deeply and not frequently."

Rebar is difficult to push into soil where the applied water no longer reaches. A tree like a bottle tree should have wet soil from an irrigation about 24 inches deep when it is young.

Why are Pomegranate Fruit on the Ground?

Q. Something has been eating my almonds! I heard it was ground squirrels or rats. I've never seen either in my yard or neighborhood in the 12 years we've lived here. Any other possibilities?

When almonds are gnawed from the husk and shell it is most likely ground squirrels this time of year

A. The varmint was chewing the outside husk and stealing the almond inside the husk, leaving part of the husk behind. They drop the husk chewed off onto the ground. This sounds like ground squirrels to me. Ground squirrels are the number one pest for stealing almonds. I have had ground squirrels clean out an entire 15 year old almond tree of nuts overnight.

Pomegranate fruit is lying on the ground. A no-no. Always prune the tree so that these limbs support the weight of its fruit. As the limbs get older and stronger, removal of side limbs to about knee height is good enough. When the limbs are young they are more flexible and cannot support the fruit adequately.

But rats will eat anything so they have a lot more to pick from in the summer. Like garbage. I don’t know if they will want the nuts at this time of year. Because it is just the nuts and there is plenty of other food around, I am putting my money on the ground squirrels. I don’t know of any other critter that will take almonds this time of year. To control this problem, I removed the ground squirrels with concealed poison bait but traps are available.