Xtremehorticulture

Xtremehorticulture of the Desert

Prune Larger Shade Trees to Save Water and Be a Good Neighbor

Leave a Comment / African sumac, fruit trees, how to prune, pruning large limb, removing large limbs /

 Q. I have a 20-year-old African sumac nearly 30 feet tall which provides great shade in my backyard. It needs another pruning when it cools off. I did a major cutback last fall at the request of my neighbor because of leaf drop. Any suggestions on how best to do so and keep the shade and cooler temperatures it provides? Drop crotching an African Sumac that is too tall will save water. A. Two things you need to know if you are doing this yourself; drop crotching and how to do a 1-2-3 pruning cut. Stand away from the tree so that you can see all of it. Identify the limbs giving you the problems. Trace the limbs back to a lower crotch. A crotch is where at least two limbs come together. This is where the pruning cuts and lowering will be done. In a 1-2-3 cut the first cut is made 12 inches from the tree trunk and upward to prevent a large limb from pulling the bark from the trunk Make a 1-2-3 Pruning Cut During cooler weather remove the limbs that are offensive. Use a 1-2-3 cut to avoid stripping the bark from the tree. A 1-2-3 cut is done first by making an undercut six inches from a limb to about 1/3 of its diameter. The second cut is made outside of the first cut. Attached bark may strip down to the undercut, or first cut, so the falling limb will not tear the remaining limb and tree trunk. This is why the undercut is made first. A third cut is used to finally remove the remaining stub. It is a finished cut. The third cut is the smallest cut made that removes most of the stub remaining so the cut heals faster. If you have never done it, for safety reasons and a better-looking tree, hire a certified Arborist to make these pruning cuts so that it will make the tree smaller and keep it beautiful. Part of your payment is for decisions that result in a prettier tree than you could have done.

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Fall Vegetable Planting Use Your Phone App

Leave a Comment / cool season vegetables, fall planting, Hot summer, predicting when to plant /

 Q. Because of the continuing heat through September, when would we plant vegetables for our home gardens. What veggies would you recommend for the first planting? Ideal vegetable seed germination temperatures oriented for spring planting when soils are colder. In the fall soil is warmer and gets colder. For fall gardens work backwards with this chart. A. The Fall planting season is always uncertain. Weather phone apps help our guesstimates for about two weeks.  What is seen on vegetable planting lists are averages of the planting dates for that season. For each season you should look at the 10 or 14 day forecast from your phone app. Fall Means Cool Season Vegetables In the Fall the focus is on planting “cool season (winter) vegetables”. Its kind of a misnomer because there is no such things as “cool season” and “warm season vegetables”. That is a human invention to categorize the vegetables we eat. Plants grow best along a continuum from 45 to 90F. Some plants grow better during cooler weather and others during warmer weather. Humans divided vegetables into these two groups. This weather phone app is typical for Pahrump, Nevada. https://pvtimes.com/wp-content/uploads/2017/12/web1_1007-weather_7153434.jpg Use Your Phone App Use your phone app to pinpoint when to plant by looking at the following ten days of weather. Let’s use sweet corn as an example. Soil warmth isn’t a problem in the Fall like it can be in the Spring. Sometimes during the Spring, the soil must be warmed first to get growth from some of the warm season veggies, like tomatoes, peppers, eggplant and watermelon.  In cooler soils they just sit there, wonderful-looking, with no growth. Work Backwards We are now transitioning to the “cool season vegetables”, so a warm soil is a blessing for them. Again, not like the spring with its cooler soils. Start with the so-called “warm season vegetables” first. Because we are planting in the Fall, start at the middle of the chart I attached and work backwards for planting times. Remember some cool season vegetables have a long production cycle (like sweet corn as an example). On crops with a long production cycle, plant early in the late summer and use varieties that have a shorter production time (like those varieties that are harvested in 60 to 75 days)! Save Germination Time Due to Warmer Soil Because you are planting in the fall when soil temperatures are warmer you can normally subtract five days from the production time on the packet (e.g., instead of 70 days for production, use 65 days) if you get it in early enough and wind is not a problem. Using 70-day sweet corn as an example, guess at the harvest date (say Nov 15). Plant in 65 days less than that (approximately Sept 10). It’s still a gamble that far out but can be worth it!

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Differences Between Xeric and Mesic Plants

Leave a Comment / landscapes, mesic, shrubs, trees, xeric /

             Many homeowners don’t know the names of plants in their yards or landscapes. Most can look at a plant and know if it is a tree, shrub, or flower but not its name much less how often it should be watered and with how much. This pyracantha was known as a “plant with berries” to a homeowner trying to calculate its landscape water use. Pyracantha does have berries but it is considered “mesic” in its need for water. Xeric plants vs Mesic plants Lower water use trees, shrubs and flowers are watered less often. They should get the same amount of water when they are irrigated but don’t need it as often. That’s how xeric, or lower water use, plants operate.             One way to find out if an unnamed plant is xeric is to water it less often during the cooler months. In the long run xeric plants are watered less often. That’s how they, and you, save water in landscapes. If it starts looking bad to your eyes or dies, then it is most likely not xeric. Big Trees are Seldom Xeric             Another method is their size. Big trees are seldom xeric. Xeric plants are not big. They tend to be smaller. The bigger xeric trees and shrubs grow where water collects; arroyos, waterways, and desert springs. This young shoestring acacia is a 40 foot tall mesic tree from Australia that grows along waterways. This shoestring acacia was “topped” (not done that well I might add) probably because it was getting too tall for that spot. Shortening its height will reduce its water use but not how often it needs water. Big trees use more water than smaller trees. This is true even if you buy one that is small and it grows big when it gets older. Just like kids. You don’t know if your child will become tall or not until they get closer to that size. Oh wow…which side of the family did HE/SHE come from? How to Reduce Water Applied to Your Landscape             During these cooler fall months, start watering less often and see what plants start looking not so good. Try adding more drip emitters to those plants looking not as good as you are watering less often. This gives these plants more water but still less often.

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Remove All Roots of Palms During Removal?

Leave a Comment / coir, date palm, soil mix, sucker /

Q. We have decided to have our Mexican fan palms removed. Do we need to have all the roots removed or just cut the palms down to the ground, especially the one next to the pool? Suckers from palms such as date palm are oftentimes removed when they get larger.  Success rate depends on taking a small amount from the “mother” palm as well as the sucker. A. If your palm trees do not sucker from the base (date palm, Mediterranean fan palm do produce suckers from the base) then as soon as the top is cut off, the palm will die. Both Mexican and California fan palms have one central bud at the top which is the only place where new growth can occur. Once cut and they die, they will slowly decay if left behind. Suckers from date palms are usually removed when bigger. Palm “Wood” Rots Very Slowly             The problem you will have when you leave any kind of stump is the palm trees very slow decay rate. Palm debris decay or rot very slowly. Coir is taken from coconut palms and is used in soil mixes to build soil structure because it resists decay. It is slow to decay and is the main reason I discourage its use in compost piles or use in woodchip mulch. It makes a great semi-permanent component in soil mixes. In both cases you want fertilizer or compost added to circumvent its slow decay. When plants decay, they add to the organic content of the soil and help make it darker. Coir is an ingredient we use in our soil mixes at our farm in the Philippines. Why? Because it is available and cheap. Remove as much of your palm trunk as possible. The palm roots won’t regrow, but any debris left behind from the trunk will decay very slowly. If you decide to use it in your new soil mix (it is a great addition to soils to improve soil structure), chop it as small as possible and make sure that fertilizer or compost is added to the soil to compensate for the slow breakdown of palm debris. By the way, water from pools is not all that desirable by any plants if they are getting enough water from irrigation.

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Elephant Ears Not an Easy Choice for the Desert

Leave a Comment / alocasia, colocasia, desert, elephant ears, taro /

 Q. What went wrong after I planted Elephant Ears (Colocasia spp.) in my back yard planter? I planted Elephant Ears last summer and at first it appeared to flourish. Very soon thereafter it began to wilt and appeared burnt. Then of course it died. The planter is covered in river rock. The irrigation to it, I believe, was sufficient for the plants. The planter also holds one lemon tree and two very tall queen palms, and they were fine.  I was wondering if the river rock created too much heat? Taro (Colocasia esculenta), called gabi in Filipino, as it appeared at our farm in Batangas, Philippines, is a close relative to Elephant ears (Colocasia spp.) Elephant ears is an ornamental type grown for its big “ears” or leaves. A. The river rock had nothing to do with it. Colocasia or elephant ears has a lot of things going against it in this climate; it is tender to any kind of winter cold, it is an understory plant so it does not like direct sunlight, desert soil doesn’t have enough “organics” in it so it must be amended, and the soil should stay moist because it likes wet areas.        This particular elephant ears is a close relative to taro and yam. Another plant closely related to it is Alocasia spp., which also has big leaves and is sometimes called elephant ears as well. All elephant ears require a lot of babysitting in our desert climate because they are really tropical plants. Just Because its Tropical Doesn’t Mean it Cant Grow Here The best spot for it is in partial or filtered shade, planted in soil high in “organics” and kept moist. Move it into a garage when winter freezing temperatures threaten it, similar to banana and plantain. Elephant ears is grown for its roots and leaves, not flowers so it can grow in lower light levels than fruit trees like lemon. Sounds like a lot of work to me. It did well in the spring and would do well in the fall because of cooler weather, but struggles during our hot, dry, windy summers, and freezing winters. Lemons have a better chance. ‘Meyers’ lemon tolerates some freezing winter cold temperatures better than other lemons. Queen palms don’t like our dry winds. They get ‘ratty’ looking. If you want to try it, grow it only on the north side of a home in bright sunlight under shade cloth. Amend the soil with compost. Keep the area moist as it will not like dry soil at all. You must address all these problems; cold winter temperatures, amend the planting soil, provide a location where it can get as much protection from the sun as possible without a lack of it, keep the soil moist and windless as much as possible. It is not like a citrus or queen palms where you have fewer things that are a challenge for it here. The more a plant is grown out of its native environment, the more time, emergy and expense is need to keep it healthy.

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USDA National Organic Programs Updates List of Approved Chemicals

Leave a Comment / organic, USDA organic program /

  USDA Publishes Advance Notice of Proposed Rulemaking Inert Ingredients in Pesticides for Organic Production Today, the USDA National Organic Program previewed an advance notice of proposed rulemaking (ANPR) that asks the public to comment on options to update how the National List of Allowed and Prohibited Substances (National List) references inert ingredients in pesticides allowed for organic production. The National List currently uses Environmental Protection Agency (EPA) inert ingredient lists, but these lists are no longer maintained by EPA and are out of date. USDA is asking the public to comment on options to revise the National List, including several derived from NOSB recommendations. USDA will use feedback gathered from public comment to inform any future rulemaking about inert ingredients in pesticides. The public comment period opens today and closes on November 1, 2022. Be part of the policymaking process and make your voice heard—click on the link below to read the ANPR and submit a comment. Read and Comment on the ANPR   About the National List The National List is a tool for managing the substances used in organic production. In general, natural substances are allowed in organic production, and synthetic substances are prohibited. The National List identifies the limited exceptions to these general rules. Changes to the National List require a National Organic Standards Board (NOSB) recommendation and USDA rulemaking, a process that provides multiple opportunities for public comment. More information on the National List, including how and why substances are added or removed from it, is available on the USDA, National Organic Program, National List webpage. Organic Integrity from Farm to Table. Consumers Trust the Organic Label. Organic Insider Archive

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Estimating How Much Water Landscapes Use

Leave a Comment / irrigation, landscape, landscape water use, plant water use /

 When you estimate a plant’s water use, the plant must be growing all by itself. When plants are grown together the roots intermingle, their branches might intermingle creating shade and wind diversions, not only that but its water use is confused with any neighboring plants close by! When you estimate a landscape water use, use the total sum of all your plants. It will be a little high because of influences by plants nearby. This can be estimated by someone who knows plants and their water use. For a traditionally sized family of four, landscape water accounts for about 70% of your water bill. When recording the water use of plants, they must be separated from other plants such as using this weighing lysimeter and hoisting the individual plants. How many square feet is your total landscape? Your landscape size is your lot size minus the house, patio, driveway, sidewalks, and any other hardscape that would be difficult to remove. The problem is your monthly water bill comes, at best, in gallons of water. Landscapes vary in size. The size of your landscape is in square feet. Water bills, like this one from Henderson, NV, lists the water use of an entire home lot. You must multiply this by  approximately 0.7 to get the actual water use of a landscape. You must convert the gallons of water used by your landscape to the size of your landscape in square feet. The multiplier you needed is to convert a landscape from cubic feet to gallons. The magic number that does that is multiplying the square footage by 7.8. That is, 7.8 gallons fits into a one cubic foot spot. Two cubic feet contains (7.8 gallons x 2 cubic feet) 15.6 gallons for every 2 cubic feet. The front landscape size is calculate from the total landscaped area, not including the driveway, sidewalk, or any so-called hardscaped area. Any time your annual gallonage represents less than two feet of water covering your entire landscape, you are doing a very good job! That is less than two feet of water needed to water your landscape each year! When the landscape gallon totals less than 4 feet deep, you are doing an acceptable job. Six feet or more is unacceptable for desert landscapes. For instance, let’s say your landscape area totals 2000 square feet.  This size includes every possible spot a plant can be planted. Two feet of water covering this landscape area = 2000 x 2 x 7.8 = 31,200 gallons of irrigation water per year. That is very good. Four feet of water covering your total landscape area = 2000 x 4 x 7.8 = 62,400 gallons of irrigation water per year. That is acceptable. Six feet of water or more covering the total landscape area (2000 x 6 x 7.8 = 93,600 gallons of irrigation water per year) is unacceptable.

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Calamondin, or Calamansi, Tender to Winter Temperatures in Las Vegas

Leave a Comment / calamansi, calamondin, citrus, fruit /

 Q. I received a young calamondin tree from a friend in memory of my father’s passing. I would love to nurture and grow this tree successfully. Any tips? Is it likely to bear fruit? How long should a small nursery stake remain? To start side branching and protecting its trunk from the intense desert sunlight, this tree should be pruned at about knee height. During the next three years, leave it alone. A. I am sorry for your loss. In the Philippines, where it is a native, it is called calamansi in Filipino or Tagalog. So therefore, it is subtropical, and it will not tolerate freezing temperatures, much below about 28F. If we get a cold winter, it can freeze. It does not like our desert, so it prefers locations on the north or east side of your home. And lastly, it likes amended soil so plant it either with compost mixed in the soil (one shovelful for each three of desert soil). It grows best in soils covered in wood chips. However, if your soil is covered in rock, then rake back the rock and apply about a quarter of an inch of compost and water it in. Do this every other year. Never plant in a dry hole. The soil in the planting hole is wet and filled with amended soil.  When staking fruit trees they don’t need a large tree stake unless they are huge. Use the stake that came in the container. After planting, push it deeper and tie the tree to the nursery stake with stretchable nursery tape. Remove after the tree is growing well, usually the next year.              When planting it, pound the stake into the solid ground beneath the planting hole so that it supports the tree. Then tie the tree tight to the stake with green nursery tape. Remove the planting stake and tape after one growing season. When it gets established but still young, form a small tree by pruning it at knee height. Remove any limbs that are growing along the trunk below this cut. Don’t expect this kind of crop on your tree. This is exceptional and can result from planting in the right climate, providing fertilizer and water when it needs it.  The fruit is about the size of a large marble or small golf ball and the juice and pulp is tart, like a lime. The tree should start bearing fruit when it is still small and young, perhaps the second year after it is planted. The production of fruit will become more as it gets bigger. It is harvested when the green color of the rind starts to turn from green to light green. Filipinos use it for flavoring fish (by squeezing a cut fruit seeds and all) and also as a beverage like a lime and many other things. 

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Chinese Pistache Should Never Be Watered Daily After Planting

Leave a Comment / container planting, donut, moat, ring /

 Q. I purchased a Chinese Pistache one year ago that was about 12′ tall; not a small tree. Everything was fine until July, about 11 months after planting.  The leaves went from deep green to dry and crunchy, quickly.  The tree was watered twice a day for 25 minutes during the summer. The supplier of the tree told me it was insect damage and to water once a day for 45 minutes longer. My concern is that all the landscaping is on the same zone. It is all doing extremely well. The landscaper has recommended 20-25minutes/ twice per day. I’m confused because I was told that what will kill the tree is if the soil is too wet. Chinese pistache tree recently planted. A.  Your watering schedule is very confusing. Part of the confusion is that everything is watered the same.  In landscapes, trees and shrubs should be watered separately from those plants requiring daily irrigations. In other words, trees and shrubs are watered separately from those requiring daily waterings. Daily summer irrigation is required only by lawns, flower beds and vegetable gardens. Instead put a donut or moat around the tree to force more water toward its roots. The frequency of irrigation (on and off) is only controlled by the irrigation valves. Irrigation valves do not control the amount of water plants receive. The amount of water they receive is controlled by the size and number of irrigation emitters. Trees and shrubs are deeper-rooted; the amount of water they receive should only be controlled by irrigation emitters. The amount of water each plant receives depends on its size.  Larger plants require more water than smaller plants. Irrigation controllers dont have to be as fancy as this one. Figure out what you need it to do. The primary function of an irrigation controller is to turn irrigation valves on or off. Never plant anything living in a “dry” hole regardless of the time of year it’s planted.  The hole should always be moist or at least “mucky” when planting.  After planting is finished, give the soil a chance to start drying before watering again. This should be at least one day except when planting in pure sand. If your trees and shrubs are watered the same as everything else in the landscape, it is being watered wrong.  There should be at least two irrigation valves; one irrigation valve is needed for summer daily irrigations, and the second valve (or other valves) is needed for watering everything that is not watered daily in the summer. Notice I said at least two irrigation valves. Your landscape probably needs more than two.             Next, connect an irrigation valve to those plants requiring daily summer irrigations (lawn, flower bed, vegetable garden;). These are the only plants connected to this valve. Reserve the second valve for bigger plants needing nondaily irrigations. At planting time, dig the hole for plants three times the width needed to just barely fit the plant in the hole. Not just a hole big enough to fit the plant in and call it done. This is the desert. Soils need to be amended for planting and the planting hole needs to be wide, not necessarily deep.

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Lawns Mowed Too Short Can Be Problem Areas for Weeds

Leave a Comment / spurge, Weeds, white milky sap /

 Q. For years I’ve had a problem with weeds in certain areas of my yard. They arise in July and continue during our humid monsoon season. Every spring I give my lawn a couple of doses of Scotts ‘Weed and Feed’. I’m tired of pulling weeds by hand. It’s very tedious work and I’m now up there in age. Spotted spurge invades open areas that have lots of water. They are a small weed with small white sap that exudes from broken stems. A. The weed you are talking about is called “spotted spurge” because of its dark spots on its   tiny leaves. It is a low growing spreading weed with a milky sap when you break their spindly and thin stems. It spreads quickly into unprotected areas and germinates from its own seed which it spews everywhere from its tiny flowers. Spotted spurge invades an open area that is wet. It has “milky” white sap and spots on its leaves. All spotted spurge are considered “weak competitors” when shaded by other plants or the soil is covered by a thick mulch, and quickly invades areas after a rain or during frequent irrigations.  In the desert it favors the frequent irrigations of lawns, flower beds, or raised vegetable beds. Lawn grass with dead or dying areas should not be cleaned up until you are ready to plant grass seed in the fall or spring. Also raise the mower height and never mow the lawn below 2 1/2 inches tall if fescue. Because it’s a weak competitor, spotted spurge is controlled by covering these open areas with three inches of a surface mulch or shading these same areas with other plants. The existing plants must be killed first and then immediately apply a preemergent weed killer to that attacks the seed before it germinates. A thick layer of mulch helps to prevent many weeds from starting and becoming a problem. It doesn’t help with common bermudagrass and other perennial weeds that are tough to get rid of. To address your situation, first kill the existing plants. This can be done with a hoe, pulling them, or killing it with chemical such as Monterey’s ‘Spurge Power’ and then removing the plant by hand after it dies. As soon as the existing plant is removed, immediately apply a preemergent weed barrier such as any chemical applied as a pre-emergent weed killer that controls crabgrass. The pre-emergent weed killers last about 30 days if left undisturbed. 

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