Xtremehorticulture

Xtremehorticulture of the Desert

Palm Roots Less Likely to Damage

Leave a Comment / Damage from Palm roots /

Q. We have a large Mexican fan Palm in our courtyard which is now about 15 feet tall. About 5 to 6 feet from the tree is a “Pebblestone” plastic divider which is slightly raised. The Pebblestone representative said it is likely root problems from the palm tree. A gardening company told me the palm tree roots are not likely the problem. Which is it? A number of people asked me about the damage from Palm roots two different types of hardscapes. Here is the skinny on this topic. This picture is not from the reader but someone else. A. Palms are a different type of plant altogether from ornamental trees. They are monocots while most ornamental trees are dicots. The internal physiology and anatomy is very different between the two. Palm trunks are much different from the trunks of other types of trees. It’s full of these long fibers. The inside is more similar to the inside of a grass plant on steroids.             Palm trees grow differently and have roots that are very different from ornamental trees. Basically, palm roots grow closer to the trunk while ornamental tree roots can, if water is available, grow a distance horizontally twice their vertical height. In Las Vegas resident asked me to intercede regarding the claim by an HOA that palm tree roots were damaging a wall that needed to be repaired. As you can see, this palm tree was growing right next to the wall and causing very little damage, if any. That’s the good news. The bad news, oleanders growing in the same area were probably the culprit.             Ornamental tree roots are larger in diameter closer to the trunk and smaller in diameter with more distance from the trunk. Palm tree roots don’t get bigger with length as like ornamental tree roots. Palm tree roots don’t increase much in diameter their entire length. Many tree roots increase in diameter as they grow away from the trunk of the tree. Palm roots, more similar to grass roots than tree roots, do not.           This increase in diameter of ornamental tree roots is very powerful. Heaving of sidewalks, patios, driveways, foundations, footers of walls are frequently caused by ornamental tree roots increasing in diameter if planted too close to them.             Water and where it is applied also controls where roots grow in desert soils. If you want plant roots to grow in a specific direction and not another, apply water to the soil where you want roots to grow.             I would not plant palms closer than 4 feet from anything that might be damaged. Apply water in the area where you want root growth. Do not apply it close to other areas where damage could result.             Installing root barriers to add more protection to these areas is another option.

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Nectarine Tree, Flowers but No Fruit

6 Comments / flower, fruit, nectarine /

Peach flower open and ready for a pollinator. Nectarines are peaches without any fuzz on the skin. This was taken on February 1 in the Eastern Mojave Desert. There is a danger of frost until the middle of March. This is the most sensitive stage in fruit development to freezing temperatures.  Q. I live in San Tan Valley, Arizona, and have a Panamint Nectarine that, even though it flowers, has never produced fruit. It is about 7 years old. I keep it pruned to about 8′ ft. with an open center style.  My Katy apricot grows about 8′ ft away and sets tasty fruit every year.  I am resigned to the fact that I will never taste a Panamint nectarine. The local nursery says were at about 500 chill hours. Nectarine but I don’t remember which variety. A. The fact that your tree flowered and didn’t produce fruit is a critical piece of information. People contact me and tell me their fruit trees don’t produce fruit, but they fail to tell me if it flowered or not. If a fruit tree doesn’t flower, it’s one set of problems. If it flowers but doesn’t set fruit, then it’s a different set of problems.             Your nectarine tree flowered. If it had lots of flowers, then I doubt if it’s a lack of chilling hours. Panamint nectarine is self-fruitful, it just needs bees present when it flowers. If there are a lack of pollinators, then you will get a very poor fruit set. Whenever lots of bees are present at the time of flowering and there are no other problems, you get lots of fruit. Nectarine new fruit developing after pollination.             Late spring freezes can be a problem with some varieties of all fruit trees. Some varieties are more sensitive to freezing temperatures than others. This can be true of some varieties of peaches and nectarines.             It can also be true of your location. If you are located in low areas where cold air can accumulate, there is a greater chance of having late spring frosts. Trees that are on slopes where cold air can drain away from them are less likely to have losses due to late spring frost. The most critical time temperature-wise is when the flower is open and through anthesis, i.e. when the petals fall from the flowers. Arctic star nectarine in bloom about ten years old but pruned to open center and kept below 8 feet tall.             Tolerance to colder temperatures is greater before the flower opens and after the newly formed fruit has had a chance to gain some size. We are talking only a couple of degrees Fahrenheit but that can mean the difference between setting fruit and not setting fruit. Immediately after anthesis..when the petals fall from the flower. This peach flower was pollinated and the pitcher-shaped receptable has swollen and ready to grow into a peach fruit. Freezing temperatures, dipping below 32° F, can easily kill this tender receptacle at this stage and cause the flowers to drop from the tree without producing any fruit.             I never liked Panamint very much. I had them growing at the University orchard and pulled them out after they fruited a few years. I don’t like the tree and I didn’t like the fruit. Nectarine fruit developing             After that many tries and getting flowering but no fruit, I would get rid of it. My favorite nectarine so far is Arctic Star. It is a white nectarine with wonderful flavor and aroma. It is one of my favorite fruits of all time. I never had a problem with fruit setting even when other fruit was lost due to late spring frost.             I don’t agree 100% that chilling hours is that important for several types of fruit. Perhaps some fruit trees are not as sensitive to chilling hours as others. I don’t know. I am growing peaches with 900 chilling hours for 20 years and we have about 300 units in Las Vegas.

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Green Yellow Citrus Leaves in Winter

Leave a Comment / iron fertilizer /

Q. My calamondin tree has yellowing leaves. I found this Liquinox iron and zinc plant fertilizer at Home Depot. My question is at this time of the year, can I apply it to my tree? A. Yes, as a foliar spray. For those not knowing calamondin, it is sometimes called calamonsi in the Philippines. It is a citrus similar to a small lime.  You would waste your money applying it to the soil unless the soil pH is about neutral (7). I looked at the label. Dilution, use distilled or RO water and apply with a spray bottle. Because it has Yucca extract in it you should not need a wetting agent to get it inside the leaves. Repeat sprays weekly. Might take 3 to 4 applications to see results but each spray it should get darker. Do not use tap water if the pH of the water is too high for this product. You need a pH of about 7 or lower for this to work right.

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Prepare for Pruning This Winter

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            Winter fruit tree pruning starts as soon as leaves drop from the trees. It’s easier to see the branching structure of the tree, I call it the tree’s “architecture”, after the leaves are gone. This is also the time for the major pruning of landscape trees and shrubs. One-year-old Peach tree ready to prune as soon as the leaves drop             Palms are pruned after new growth and flowering in late spring or early summer and coinciding with flowering and seed production. Removal of flowers and seed at the same time reduces Palm tree litter. Weight to prune palm trees until after they flower but before they drop their seed.             Speed up leaf drop by shutting off the water. This puts them under a little bit of stress which speeds leaf drop. Turn the water back on when the leaves begin to turn color. Plum parfait pluot just turning color and ready to drop leaves soon. Speed it up by turning off the water.             Prune fruit trees anytime in December and January. Reserve grape pruning for the end of February. Roses are traditionally pruned in January.             Fertilizer applications to most fruit trees, landscape trees and shrubs is done in mid-January and into February. If you see buds swelling on branches, fertilize the trees.             Lawns, annual flowers, vegetables and “specialty” plants like roses are fertilized 3 to 6 times a year depending on your expectations and budget.

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Save My Pindo Palm!

Leave a Comment / irrigation of palms, liquid fertilizer spray, Palm yellowing /

Q. Is there any way to save my Pindo palm?   This Pindo palm has yellowing coming from newer palm fronds and is very small for a ten-year-old palm. The yellowing is nutritional but can be aggravated from watering too often, poor drainage from the soil surrounding the roots, salts or a lack of fertilizer and any combination. A. Looking at the picture, very poor growth of this young palm and most of the center leaves are yellow. I am guessing this palm is growing in soil covered by rock and perhaps was not planted properly.             The soil after a few years, reverts to its desert origins, the chemistry of the soil changes and plants have trouble finding available nutrients. This is what some native desert soils can look like; almost zero organics, hard to dig as cement, and very poor drainage. Adding organics to the soil at planting time, like compost, is a partial solution. Covering amended soil with rocks and never adding anything more causes the soil to revert to its origins.             Perhaps they are watered too often and the soil is not given enough time to drain. This “drowns” the roots, suffocating them. Putting “good stuff” like compost mixed in the soil at the time of planting is important. They “open” the soil and improve drainage as well as provide nutrients.             Now on to watering. I am believe in giving plants plenty of water when they need it and not giving them “tiny sips” of water daily. Giving tiny sips of water is a “Hail Mary” attempt at landscape irrigation. Some landscapers and many landscape architects now install drainage pipe vertically in the planting holes around palms. On top of that, they specify surrounding the root balls of palms with sand. This forces the palms to rely on conventional fertilizers for their nutrition.             A young palm a few years old should get 10 to 15 gallons each time it’s watered. This time of year, watering once a week should be enough. This is a Queen palm planted in the Eastern Mojave Desert. It shouldn’t be planted here in the first place. The Mojave Desert is too harsh of a climate for Queen palm. But this yellowing is signaling its need for better nutrition. The poor nutrition could be the result of watering too often and poor soil drainage of water.             Even if yellowing is caused by watering too often, it can be corrected with liquid fertilizer sprayed on the leaves. The problem is not knowing which nutrients are causing the problems.             Use a shotgun approach when applying fertilizer sprays to the leaves. Products like Miracle Gro, Ferti-Lome, Jobes, each have a line of powdered fertilizers that can be mixed in water and sprayed on the leaves. Look for a smorgasbord of nutrients listed in the fertilizer. Miracle Gro is one example of a water soluble fertilizer that can be sprayed on plant leaves. There are many out there.             This is another example of a water-soluble fertilizer that can be mixed with water and sprayed on the leaves of plants. This shows you the three numbers.. Sometimes four.. That appear on these fertilizers. These numbers would be okay in this case but I would like to see the last number closer to the first number in this particular case. Use distilled or RO water and not tap water. Add a teaspoon per gallon of liquid “baby soap” or Castile soap and foliar iron to the mix. Spray the fronds on top and bottom until they begin dripping. Repeat this spray two or three times a week apart. This is an example of a “soap” or detergent that helps move the fertilizer inside the plant leaf. Very important when you are spraying fertilizers on a part of the plant with no roots. I like this particular one because it is plant-based and all-natural. But you can use Castile soap and mild soap made for babies. I wouldn’t use liquid dish soap unless it doesn’t have any perfumes or hand lotions.             Take 2, one cubic foot bags of compost and apply it to the soil beneath the palm. Do this once a year or replace the rock under the palm with woodchips. This helps improve the soil over time.             Do not water palms daily. Water them like you would any other landscape tree.

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Control Cottony Masses on Cactus

Leave a Comment / cactus, cochineal scale, insect, white fluffy /

Q. I have small white nodules growing on my Indian cactus. Are they harmful? If so, how do I get rid of them?   Opuntia Or beaver tail cactus heavily infested with one of the cochineal scale insects. These insects can decimate cacti over time if left uncontrolled. A. I think you are talking about cochineal scale on the Opuntia or beaver tail cactus. This scale insect produces a white, fluffy mass on the pads on top of itself for protection. This insect is feeding underneath this white mass. Rubbing these white masses lightly with your finger, you find a royal purple color staining it. The insect beneath this cottony mass is dark red or purple. This is cochineal scale and makes a royal purple dye. Contrary to what some people have said, this is not the same cochineal scale the Spaniards sent back to Spain in the 1600s but a very close relative.             Depends on the cactus but they can devastate a cactus if not controlled.             First, control the ants. Ants pick up baby scale insects and transport them to pads that are underpopulated. These new pads are wide open pastures for scale insects to feed. Cochineal scale populate pads quickly. The ants harvest excrement from scale insects to feed their colony. This is a short video of a Weaver ant protecting another type of scale insect from its food supply. In this case, it’s my finger that is seen as a threat and the Weaver ant is protecting its horde aggressively. Video taken on our family farm in the Philippines.             Most ants are subterranean. One of the best methods I found to control ants is using a poison bait lightly sprinkled at the entrance to the colony. Usually these “ant holes” in the ground are easy to find but sometimes you must follow the ant trails to find them. (This doesnt work with Weaver ants because they don’t nest in the ground!)             I use an ant bait manufactured by Amdro. Follow label directions precisely. When applied correctly, it kills the entire colony, including the queen, in less than twenty-four hours. Borrowed a picture of the am drove container at Home Depot. Thanks to paulmirocha.com             Scale insects suck plant juices from the pads and build their populations quickly. Ants help them spread faster.             To remove white fluffy masses, spray the pads with a strong stream of water using a spray or sweep nozzle. This knocks the white fluffy covering off but doesn’t kill the insect hiding underneath it. They soon repopulate the pads. In summertime this could be weekly. In winter, perhaps monthly. Hosing off cochineal scale from the edible Opuntia cactus donated to the UNCE orchard by the University of Sonora – Hermosillo for demonstration trials. In the middle of summer, this had to be done weekly which none of the Master Gardeners like to do. If you don’t want to do it organically, which means frequently, then you’re faced with using conventional pesticides.              After spraying the pads with water, use organic or conventional insecticides to prevent scale insects, called crawlers, from repopulating the pads. Organic insecticides do not stay in the environment long so spray them more often than conventional insecticides. Neem oil varies in quality from different manufacturers. Unfortunately, there is not much quality control but if you find a good one, stay with it             Useful organic insecticides include Neem oil, soap sprays and other plant-based oils. Apply soaps and oils the day after spraying the pads. Reapply organic insecticides often. Organic insecticides I mentioned are total killers; they kill any insect sprayed so direct your sprays accordingly. Conventional systemic insecticides like this one works very well and requires fewer applications. But it is tougher on the environment.             Conventional insecticides last longer but are tougher on the environment. Useful conventional insecticides are systemic and applied to the “trunk” or soil. The poison moves into the pads from the point of application. Spray as soon as you see the cotton balls start to form.

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Pine Tree Recovery from the Heat

Leave a Comment / drought, heat, irrigation of trees and shrubs, pine, Super Thrive, vitamins, watering /

Q. I have fifteen-year-old, 20 to 30 foot pines on a half-acre. They suffered during the heat this past summer. After your advice, I am doubling the amount of water and hosing off the needles once a week. How long is the recovery time using vitamins?    Too much water? Probably not. But they don’t need it as often as a lawn does. When you look at the amount of water that pine trees need, the total amount of water is not far from what an efficient lawn would need. The difference is in frequency of application. Trees, this includes pine trees, should be watered much less often than a shallow rooted lawn. A. I am not a big fan of applying vitamins like Super Thrive. Some people swear by them, It can be cheap insurance though if you’re not sure. Your call on that one. Who can argue with success? The research doesn’t support it but the use of products like these (and other “me too” products) are not supported by research. However, some landscape professionals and homeowners disagree. In the long run, it’s cheap insurance to use it.             Washing the needles of pines is not necessary. It is true of Italian cypress because they tend to get spider mites. Pines do not.             They might need more water than 15 gallons. Play that by ear by watching the new growth next spring and early summer. You should get at least 12 inches of new growth every year and not experience severe needle drop during the hot months. Those are indicators the tree is not getting enough water. When you see this in a pine tree growing in the desert, it usually means a lack of water. The amount of water pine trees need is grossly underestimated by most homeowners and landscape professionals. They need a lot of water all at once but they don’t need it that often.             Once you find the right amount of water (minutes and gallons), keep it consistent through the year. The amount of water they are given should not change much throughout the year. It’s like filling a gas tank. Instead, change how often they receive the water. Summer months water more often. Winter months, water less often. One of the best ways to irrigate large trees is to “basin irrigate”. This is a modification of an irrigation technique called “flooding”. Rather than drip irrigation, a landscape bubbler (not a drip bubbler) is used to fill a flat basin. The basin around the tree, doughnut if you will or moat, must be flat! This basin is increased in size every few years to accommodate a larger tree. The bubbler emits water at one or 2 gallons per minute. The basin is full in 10 to 15 minutes.             As plants get bigger, they require more applied water, not watering more often. Watering frequently with small amounts of water produces shallow roots and trees that blow over in strong winds.             You should see an improvement in the first half of next year. Nothing this year.

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Normal for Vertical Limbs to Become Horizontal

Leave a Comment / Citrus growth, pruning /

Q.  My Seville orange tree has been growing in my yard for 20+ years. About a month ago, I noticed one of the branches that grew straight up is now parallel to the ground. Any idea what caused this?   Pomegranate growth is a little different from citrus growth. But there are similarities. According to the owner of this tree, it has not yet flowered and fruited. Its branches are vertical. After it begins fruiting the weight of the fruit will pull the branches to a horizontal position. A. The reason upright limbs of fruit trees with large fruit become horizontal is from the weight of the fruit. The fruit tree which demonstrates this the best is pomegranate. This orange tree has not yet produced fruit. Its major branches are vertical.             The upright shoots of pomegranate bend nearly horizontal after they flower and bear fruit. The weight of the fruit bends the branches downward. To a lesser degree we see this in ornamental trees and nut trees as well as they get older. This fifteen-year-old pomegranate tree has produced an abundance of heavy fruit. The fruit has waited the branches and open the canopy. Opening the canopy allows more sunlight to enter it and the tree produces more fruit. Relate this back to natural selection and evolution.             In these cases, the weight of the branch as it gets longer and heavier begins to bend the branch into a more horizontal position. Often times young trees are described as being “upright or semi upright” while the mature forms of the tree may be called vase shaped or even round.

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Best Time to Plant Trees and Shrubs Is for the Fall

Leave a Comment / planting, Planting trees and shrubs, transplanting trees and shrubs /

Proper method for planting large trees: hole is at least three times the width of the root ball, stakes are pounded into the solid soil at the bottom, tree trunk is allowed to flex without moving the roots. Q. My son and I are thinking of landscaping his front yard in December.  Will plants and trees survive when planted that time of year?   This Orchard planting the holes were dug and the soil amended before the trees arrived. The hole was much wider than the roots but not much deeper. Soil was amended with compost. Basins were constructed around each tree for hand watering over the next two weeks. A. Plant all through the winter. Is it the best time to plant? No. The best times to plant are reserved for the fall and spring months. In the Las Vegas climate it is best from late September to mid-November. Good advice!             The second-best time for planting is during the spring months of mid-February to the end of April. The absolute worst time to plant is just before and during the hot summer months. In our climate this is from May through the early part of September. Add water to the planting hole at the same time you backfill around the roots of the tree or shrub. This helps to remove air pockets and secures the plant roots in the soil. Sometimes staking is not needed when this is done correctly.             Make sure that the holes for planting are at least three times the diameter of the container and not much deeper than this unless there are drainage problems. In a few soils that have layers of caliche there are. But if your neighbors have landscape plants that are doing well then you probably don’t have a problem.             During planting make sure you are watering the amended soil around the roots WHILE you are planting. After planting water these plants by hand for three consecutive days to make sure you have removed air pockets around the roots.             Construct a basin around the plants and hand water them for the first two weeks before turning them over to drip irrigation.

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