Xtremehorticulture

Xtremehorticulture of the Desert

Ash Tree Devasted Sewer Line

Leave a Comment / Ash tree, septic, sewer /

Q. My neighbor’s ash tree grew into their sewer lines and because of that expense, I cut down  mine. My HOA says I must replace it with another tree. I am looking for something smaller with less invasive roots. Thinking about a Bird of Paradise, blue Chaste tree or a Bottle Brush? What do you think? My front yard faces West.  Ash trees for the most part make a great shade tree. Some of the older varieties can get a bit too large for single-story homes. This one is placed just a little too far and on the wrong side of the house to give it much shade. This is not a desert adapted ash tree like the Arizona hash. These older ash trees, like Modesto, do extremely well planted in lawns. A. There are two things to consider regarding your question; why the tree invaded the sewer line in the first place and reasons for selecting a replacement plant. Any of your choices would be fine to fill a space but ask yourself the purpose of this plant before making that decision. We are having a problem with many ash trees, whether they are desert adapted like this Fan Tex or not. The problem is called ash decline and I have seen it here causing problems for ash trees since the 1980s. This ash decline is bad enough that I hesitate to recommending planting ash trees at all until this can be figured out.             In our desert, I don’t particularly like the idea of selecting a plant just simply because it fills a space. Did this ash tree provide seasonal shade? On the west side of a home this can be quite important for comfort and reducing electric costs for the AC. Fan Tex ash can also get borers that can cause it to decline as well.             To improve comfort in a home and reduce energy costs, it is more important to shade the South and West walls of a building than it is the roof. The most “bang for your buck” in this regard comes from deciduous (those that drop their leaves in the winter) small trees or shrubs that don’t grow much taller than the building. Ash tree roots can be quite invasive and they will go anywhere there is water and nutrients. Sewer lines sound like a smorgasbord for them!             Smaller plants generally use less water than larger ones. Pick something that can handle the heat of a Western exposure, drops its leaves in the winter and doesn’t get much above fifteen feet tall if you live in a single-story residence, 30 feet tall for a two-story residence. Plant it a distance from the wall about half of its mature height. Ash trees come as either male or female “flavors”. The trees selected and favored for landscapes are the male trees because the females make seed that drop everywhere and can be quite messy.             The second issue is invasion of sewer lines. This can happen with nearly any plant but some are, root-wise, more aggressive than others. But roots need an opening or break in the line for this to happen. If the line is completely sealed, roots will not enter it. Notice the graft union at the base of the trunk where the desirable male tree was grafted onto less desirable ash roots. This keeps the trees “male” and true to their namesake such as ‘Rio Grande’, Fan Tex’ and ‘Modesto’.             Breaks in a sewer line are more likely if a tree is growing close enough so their roots “crush” it. Crushing a sewer line because of enlarging roots causes an entry point for roots to grow. Once this entry point is made, nearly any tree or shrub becomes “invasive” and plug it. And ash trees can have nice fall color from yellow to reds to purple, weather permitting.             Use irrigation to direct the growth of roots in desert soils. People who don’t live in the desert can’t use it to their advantage. Locate irrigation emitters on the side of the tree or shrub away from the sewer line to wet the soil away from the sewer line.             Keep the area around the foundation as dry as possible a distance of at least 3 feet. As added protection, you might consider a commercial “root barrier” installed between the plant and the sewer line.

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Flavor Supreme Pluot Fruit Production Can Be Irregular

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Q. I have a 3 in 1 pluot tree (Flavor Queen, Dapple Dandy and Flavor Supreme) that I purchased 5 years ago from the Master Gardener University Orchard. The canopy is about 6′ in diameter now. It has yielded fruit for 4 years. I had only 1 or 2 years of good fruit from the Flavor Supreme. I’m about ready to remove it if it doesn’t get better. Flavor Supreme pluot does quite well in the Las Vegas valley if it can get through some freezing temperatures. I have found flavor supreme to be sensitive to freezing temperatures when they are in flower or have small fruit.This makes them produce irregularly because of freezing temperatures in late February and early March.  A. Flavor Supreme pluot produces fruit erratically from year to year because of how sensitive it is to late spring freezing weather. Dapple Dandy and Flavor Queen pluots sail through light freezes and produce fruit more consistently year to year. But when it does produce, Flavor Supreme is one of the best tasting fruits in the garden. Flavor Supreme pluot in flower at the University orchard in North Las Vegas on March 8.They can flower any time between mid February to the beginning of March.             Make sure the tree is getting enough water. All fruit needs plenty of water when fruit is increasing in size. If you short the tree on water when the fruit is getting bigger, the fruit will be small. If water is in short supply, the fruit may dry up and fall from the tree. Flavor supreme pluot needing some pruning to open up the canopy for better fruit production. Look at the ground. There’s too much shade. Removing a few limbs entirely, here and there will open this canopy up for better production and better quality fruit.             Make sure the tree is getting enough water each time it is irrigated. Avoid watering daily. Add drip emitters to increase the amount of water applied. Make sure drip emitters are not plugged.             Five-gallon trees getting enough water should be at least five to six feet tall by their second year in the ground. If they aren’t, increase the amount of water they are receiving, apply wood chip mulch under the tree canopy and fertilize at least every year in January or early February.

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Avoid Salt Mayhem By Using Good Irrigation Managers

Leave a Comment / irrigation, salinity, salts /

Determining the best irrigation schedule for a mixture of landscape plants is difficult enough but when salinity is involved, either in the soil or in the irrigation water, it complicates matters. Let’s cover some irrigation do’s and don’ts and see how salinity might affect the way we irrigate. Avoid Daily Irrigations Except for shallow rooted plants like lawns, annual flowers and vegetables in raised beds, daily irrigations should be avoided any time of the year. Many turfgrasses and annuals have root systems that extend into the soil 12 inches or less. During the heat of the summer and under desert conditions some of these plants may require daily irrigations. The deeper you should water. Lawns, annual flowers and annual vegetables have the shallowest roots and need to be watered the most often. The concept of irrigating nondesert landscape plants is focused on wetting the root system to its entire depth, allowing the soil to drain and re-wetting the soil again when half of this water has been used by the plant or evaporated. The Amount of Water Applied Varies with the Size of the Plant So we can see that the volume of water applied in a single application is directly related to the depth of the root systems of plants. When designing a landscape irrigation system we try, to the best of our abilities, to put plants with similar rooting depths on the same valve or station. Create irrigation zones in your landscape that reflect the needs of the plants in it. This is because the only way to water less or more often is to turn the valve to that irrigation line on or off. This is done with the valves. So each valve should represent different irrigation depths in your landscape; trees and large shrubs, smaller and medium size shrubs and small plants. Other valves could include annual plants and lawn and desert adapted plants which don’t need to be watered as often. You could even create another zone just for cacti. (This diagram originally appeared in Sunset magazine many years ago demonstrating Hydra zoning or mini oasis landscaping) More often than not we are handed an irrigation system with a mixture of plants that have a variety of rooting depths. When deciding an irrigation schedule for a single valve or station we generally have two options; set the number of minutes based on the average rooting depth of all the plants or let the plants with deepest root systems dictate the number of minutes of station runtime. Do We Conserve Water or Minimize Plant Problems? This decision depends on whether to conserve water or minimize landscape problems. When we decide to under irrigate some plants so the majority receive the correct amount of water, we may see some plant damage. If the under irrigation is not severe, we may see the slowing of plant growth, a decline in density due to leaf drop, leaf tip or burning of leaf margins. When plants are severely under irrigated then we begin to see branch die back and in some cases death. This is a mixture of a mulberry tree with cactus growing underneath it. Water the mulberry tree and the cactus gets over irrigated. Water only for the cactus, as this was done, and the mulberry doesn’t get enough water. Under irrigating, or applying less water than dictated by a plants rooting depth, can also impact safety issues. What happens if we under-irrigate large trees such as pines which have shallow roots to take up water but require deeper roots to anchor it in the soil? Current irrigation technology is based upon time management and varying how water is applied to plants. This technology varies the amount of water applied to plants by changing the number of minutes valves are open, increasing or decreasing the points of water emission or changing the rate of water applied at the point of emission. This translates to increasing or decreasing the number of drip emitters, bubblers, nozzles or spray heads or substituting old points of emission for new ones that have different rates of application. This is a highly sophisticated Hunter ACC irrigation clock. These types of irrigation clocks are expensive but give you a tremendous amount of flexibility. They wouldn’t be good for small landscapes but an excellent choice for large landscapes that have a lot of irrigation variability. Making these changes to an irrigation system that was designed by a professional and focused on the uniform application of water, more than likely will make the system less uniform and less efficient. This will likely result in substantially higher water usage. These types of alterations to professionally designed systems must be done with care. These six station inexpensive irrigation controllers are fine for most small landscapes that don’t require a lot of flexibility. When to Make Changes in the Irrigation System? There are some obvious cases where changes must be made. For example, changes must be made when some plants are receiving excessive amounts of water or not enough water while others on the same valve appear to be watered adequately. As plants get bigger, they need more water. When plants get bigger, their tops get bigger as well as their root system. Increasing plant size requires the application of higher volumes of water. Increased plant size dictates that the area irrigated under the plant also needs to be increased. Logic tells us we need to increase the amount of water by applying it to a larger area. Just because a few plants on an irrigation valve have grown larger seldom requires increasing the number of minutes of runtime. Other plants on the same circuit that received adequate amounts of water would then be over-irrigated for the sake of a few. Is Increasing the Number of Minutes the Right Decision? Of course increasing the number of minutes is the easiest solution to the problem but is it the right one? The quick fix of bumping up the number of

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Is ‘Last Chance’ Peach Good for Desert Climates?

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Q. Will the fruit from a ‘Last Chance’ peach tree be tasty in Zone 10 or should I pull it? ‘Sugar Lady’ peach, not late but a solid performer with high sugar content from Zaiger Genetics. A. Last Chance is called “Last chance” because it is a late peach variety. ripening in late September and October. That’s the time of year you want really thinking of peaches so much but your mind starts to wander over towards apples, pears, and pomegranates. That’s a long time to keep a fruit on the tree and protect it from bugs, disease and keep the tree well watered. Personally, I like the earlier peaches because I can get them off the tree earlier so I don’t have to worry about them. Another great performer that has been around for a long time is Early Elberta with that Elberta flavor everyone thinks about when they think about a peach. It is a chance Peachpit that sprouted from someone’s garden, not one that has gone under the scrutiny by professional breeders. At Zaiger Genetics for instance, the folks that developed most of the pluots and other specialty hybrids, it takes about 5000 crosses and five or six years for each tree to get one successful fruit tree on the market. That’s a lot of investment! One of my personal favorites, but not so much because it is a great tasting peach but what peach is better when you can eat it fresh off the tree in mid-May! OMG. Early peaches, whether they are grown locally or imported from a warmer climate, command a higher price because they are early. I think part of the reasoning about Last Chance peach was that it was late when there weren’t many peaches around. The same idea just backwards. I fell in love with this peach when I first saw and tasted it. Indian Blood peach. It’s and old variety. Apologies if anyone finds the name offensive but this peach…words cannot describe the flesh color when it is ripe, the floral aroma and mild flavor of this  subacid peach.  Can anyone spell S-O-R-B-E-T? The tree will grow fine and produce fruit in the desert. I’m sure of that. But I don’t know about the quality of the fruit. I understand that it flowers relatively early in the season, the first week of February, which may be a problem with freezing temperatures in February and early March. Some peaches can sail through this kind of weather and others can’t. We had 5 of these Stark’s Saturn donut peach trees in the University Orchard. It was there second year in the ground. It was July and hot. I saw three peaches on  this tree. Two had already been nailed by birds. But this day I reached down to pick it, tree ripened, fully, slight give to the skin when you lifted it off the tree. Some juice came out on my thunbnail. It was 110F. The juice dried in a few seconds….leaving behind sugar crystals!!!!! Need I say more? I have never grown Last Chance peach in the Mojave Desert but I understand it can have a slight puckery taste, astringent, when it is ripe. It was being marketed in the Antelope Valley near Lancaster California, in the Western Mojave Desert.              I would grow this peach tree just for the flowers! But the fruit is excellent as well. Red Baron. i put in 50 at Ahern Orchard in Las Vegas (Bonanza and MLK) for the floral show in the spring AND great fruit as well. If you like the fruit, keep it. You might get peaches the first or second year you put it in the ground depending on the variety. I consider ‘Last Chance’ peach more of a novelty fruit because it produces so late.              So, my favorites usually produce in late May through July. Two notable exceptions are the Indian Free and Indian Blood peaches that produce fruit with lots of unique appeal when fully ripened. Two very late peaches for the home gardener are Carnival and Fairtime. They are proven winners in production. I have never cared for the flavor of either one but they are late, Sept and October, but at least I know they can handle some late frosts.

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Woodchip Mulch with Strawberries Might Be a Good Combination in the Desert

Leave a Comment / Strawberries, Woodchip mulch /

Q.  You have converted me to the doctrine of using woodchip mulch. Is there any reason why I couldn’t use wood chips in my strawberry bed?  My wife used to put strawberries in pots and they never did well.  Strawberries grown in Las Vegas Nevada, in Fall 2006 A. You can use woodchip mulch between strawberries. Apply compost right over the top of woodchip mulch and water it in to the soil when fertilizing. You will have to remove woodchip mulch at the end of two or three years when you pull out the old mature plants and replant with new ones. Plant strawberries in fall, not spring             Plant in mid-August, not in the spring. This is a mistake many people make. You may have trouble finding plants this time of the year since most information is focused on spring planting. But strawberries will struggle when temperatures get hot after planting in the spring. Strawberry demonstration plots prepared with compost in 2006 at the University Orchard             Improve the soil 50-50 with compost mixed with the existing soil before planting. I would include a starter fertilizer such as 0 – 45 – 0 mixed with that soil mix. A good quality compost can act as a fertilizer so don’t be afraid to apply it every three to four months after planting. Plant strawberries 12 inches apart             Here’s where I differ from what you might read. Plant them about 12 inches apart in rows 12 inches apart and remove runners when you see them. Some people also recommend removing the flowers as well. Planting in rows helps you find the berries later when the plants are full. Planting depth in A.             Plants should not crowd each other. You should see a slight separation between them for good production. Sunlight should hit the plant on all sides. Everbearing strawberry might work better             Select an everbearing type of strawberry rather than a main crop type. Main crop types produces only at one time of the year. Older varieties of ever bearing types like Ft Laramie, Quinault and Ogallala perform fine here during cool weather.             Everbearing types “trickle” their production throughout the year. This “trickling” makes them more productive here when the weather is favorable. They will produce fresh berries for 2 to 3 years before the plants need to be replaced. Strawberries do not set above 85° F             Strawberries will not set fruit very well when the temperatures are above 85°F. This makes hot, summer fruit production difficult with June bearing types of strawberries.             Keep plants alive during summer months until the cooler fall months return. Put them under 30 to 40% shade cloth draped on three-foot tall hoops during the summer months. Lay a frost cover over the top when temperatures are expected to freeze.             Water strawberries with in-line drip tubing running the entire length of the raised beds and spaced to 12 inches apart. Hand watering with the hose is very difficult. Keep soil moist but not wet to prevent root disease problems.

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When to Cut Asparagus in Las Vegas, Nevada?

1 Comment / harvest asparagus /

Q. When is the best time to stop cutting asparagus here in Las Vegas? I have a bumper crop this year. A. There are a couple of ways to determine when to stop cutting asparagus. First way is when the spears start to get thin. If you have thin spears, it is a sign the stored food in the roots is starting to get in short supply. Winter color of asparagus in the Las Vegas Valley with light freezing temperatures.in December.             Stop harvesting. Let the ferns, tops, grow until late December and then cut them to the ground, fertilize with compost to get ready for the next seasons production.             The second way is a calendar method. Cut for about two to three months in early spring, let the ferns grow and cut these ferns to the ground in late December. Fertilize with compost and start the cycle again. Asparagus knife manufactured in Kosovo from a sample I took to new asparagus growers there.             By the way, remove the spears from below ground with an asparagus knife, not by snapping off the spears. An asparagus knife is like the old fashioned, forked dandelion remover. In a pinch, I use a long knife and push it into the ground, cutting the spear. Snapping the spears leaves a “stubble” on the soil surface which interferes with next year’s harvest and management.             Wash the spears and recut the spears to the proper length for cooking. Use the bottom parts of the spears, peeled, for asparagus soup.

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How Many Gallons of Water in an Inch?

Leave a Comment / Gallons of water, inch of water /

Q. You posted a graph on your blog of inches of water plants use each day during each month during the year. How many gallons is an inch of water? Potential evapotranspiration for the Las Vegas Valley over 12 months in average inches of water used per day. Numbers across the bottom stand for months; 1 = January, 12 = December. A. I bet you want to know in minutes! That’s one problem when talking about irrigation. Irrigation clocks measure the volume of water in minutes. We apply water as a depth or in gallons, not minutes.             An acre-foot of water is roughly 325,900 gallons. An acre inch is roughly 1/12 of that which is 27,158 gallons. One inch of water in a one cubic foot container is 7.48/12 = 0.62 gallons.  Taken from my manual, Basic Horticulture             One inch of water applied to pure sand penetrates to a depth of about 20 inches. Fine sand, 14 inches deep. Fine sandy loam, 10 inches. Silt loam, 7 inches and clay loam, 6 inches.             The amount of water to apply is determined by the depth of its roots. The shallowest rooted plants are lawns, annual flowers and annual vegetables. We assume the depth of their roots is less than a foot. The next deepest-rooted plants are 2 to 4 foot tall perennials with a rooting depth of 12 to 18 inches. And finally, trees and large shrubs are the deepest with an effective route depth of about 24 inches.              Larger plants are given more water but watered less often because their “gas tank” (water held in the soil available to the roots) is much bigger. Plants that are shallow rooted like lawns, annual flowers and vegetables are watered more often because their “gas tank” is much smaller.             It is very important to group these categories of plants (lawns/flowers/vegetables, medium sized plants, trees and large shrubs) on separate irrigation valves. In this way they can be watered separately and at different times. Fourth and fifth categories, desert plants and cacti, could also be argued.

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Grapevine Not Leaving out This Spring. Dead?

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Q. I have four grapevine bushes. We had a freeze these past two years. Two of them are doing fine, however, two others have not produced new leaves since last year. Does that mean they are dead? How would I check if they are dead? This grape was from a previous reader in Canada but a dead grape vine is a dead grapevine, right? A. Some grapevines are more tender to winter freezing temperatures than others. Some of the European wine grapes, or those with wine grapes in their heritage, may possess less tolerance to freezing temperatures. We refer to these grapes as “vinifera” type grapes. Thompson Seedless, for instance, is in this category and many California table grapes.             Most of these grapes will not tolerate temperatures much below 20° F. Expect them to freeze to the ground while other, hardier grapes may sail through the winter unharmed.             If you don’t live in wine grape producing areas, I prefer to grow grapes on their own roots rather than grafted onto a rootstock. If they freeze to the ground many of them will regrow from basal suckers. If they are grafted on a rootstock, then you might as well throw it out.             Cut the top of your grape back, close to the ground. Let it sucker from the base. Select the strongest sucker and re-tie it to a grape stake with nursery tape. Remove the other suckers.             If you push its growth hard with water and nitrogen fertilizer, you can reestablish it back on the trellis in one growing season. With some grapes I have been able to regrow it on the trellis and have it set fruit during first year of establishment.

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Never too late To Prune Lantana

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Q. I put off pruning my lantana. They bloomed until about a two weeks ago. Now, they are starting to cycle through the dying and rebuilding process. Can I prune them back now, the normal way, and still have good growth? A. So, I take it, you did not prune your lantana this winter because it did not freeze. Or you just forgot. Now you are wondering if it’s too late to prune. No, it’s not too late. Do it now even though it’s starting to grow again.             Lantana is what we call an herbaceous perennial in our climate. Winter temperatures are usually cold enough that the top freezes to the ground each winter. Spring pruning removes the top, close to the ground, and it regrows again from its base or crown. This winter it did not get cold enough.             You know it has the potential to grow from its base. Cut it back hard to within 1 inch of the soil surface and it will “sucker” below these cuts. Give it some fertilizer and water after you make the pruning cuts.

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Tangerine Leaves Curling

Leave a Comment / citrus, leaf curl, tangerine /

Q. Please help me to recover my tangerine tree leaves curling inwards. Most have very small black spots on them. l observed the leaves and don`t see any insects. l do deep hose watering during hot summer days. Picture of tangerine leaves curling and dropping A. There are lots of reasons for citrus leaves curling. This problem is near legendary for citrus leaves but the reason is usually environmental and not from insects or disease. I’m not saying it can’t happen but it’s less likely. Citrus troubleshooting guide Arizona Cold weather             Since this question was sent to me at the end of winter, cold weather comes to mind. Cold temperatures can cause leaves to roll. Some say cold weather can cause leaf spotting as well. If leaf rolling was during the summer, guess what? High temperatures can also cause citrus leaves to roll. Watering             Moisture stress can cause leaf roll and leaf drop. When timing irrigations, make sure the soil is no longer wet when the irrigation water is applied. In the same token, make sure the soil does not get too dry between irrigations. Dry and wet soils can cause leaf rolling.             What’s more important, in my opinion, is overall tree health. Plants in poor health are more susceptible to problems than those that are healthy. Soil problems             In the picture you sent, I noticed the condition of the soil surrounding these trees. The soil looked pretty bad, even by Las Vegas standards. Poor soil conditions leads to poor plant health in the future.             Good soil health begins at the time of planting. I realize your tree has already been planted but soil improvement surrounding the roots at the time of planting is a huge future investment in plant health for years to come. In the future, excavate the planting hole 3 to 4 feet in diameter and 18 inches deep at the center. Mix good compost with your excavated soil at a rate of about 1:1; for every shovelful of soil, mix one shovelful of compost. What to do?             What can you do now? Put a half bag of compost on the soil surrounding the tree. On top of this, put a 4 to 6 inch layer of woodchips and water it in. Woodchips, where irrigation water is present, improves the soil health where most of the feeder roots of your tree are living. Spreading good quality compost at the base of trees for its fertilizer content             Improving the soil improves water, fertilizer and nutrient uptake by these roots which in turn improves the overall health of the tree. Soil improvement using this method helps remove some irrigation problems that could be causing leaf rolling. Overall, this means fewer problems for your citrus in the future. Community mulch pile at the University Orchard North Las Vegas             Get these woodchips free by visiting Cooperative Extension locations south of the airport or in North Las Vegas at the University Orchard in the Aliante community. For more information about these free woodchips call the extension hotline at 702 – 257 – 5555.

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