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Monday, November 20, 2017

Normal for Vertical Limbs to Become Horizontal

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.

Sunday, November 19, 2017

Best Time to Plant Trees and Shrubs Is for the Fall

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.

Let's Get Ready to Prune Fruit Trees!

Q. Can I prune fruit trees now or do I need to wait until they are dormant in January?  Will you be giving fruit tree pruning classes again this year?
A. Prune fruit trees lightly with a hand pruner any time there is a problem at any time during the year. Heavy pruning that requires a saw or loppers should be done during winter months after leaves have dropped.
Hand pruner or hand shears for making cuts less than 1 inch in diameter
            Removal of limbs with loppers or a saw is easier after leaf drop when you can see the arrangement of limbs and branches and where to cut. Avoid using loppers or a saw during summer months because of sunburn and damage to the trees by our intense sunlight.
Loppers used for large cuts greater than 1 inch. The maximum size for a lopper depends on the lopper and how well it's maintained and the person doing the pruning. Some people are not physically capable of making some larger cuts. Once cleaned and sanitized, they should never be placed on the ground because of sanitation.
            The majority of pruning cuts for fruit trees will remove entire limbs and not leaving “stubs” where branches are cut off. Many of the desirable pruning cuts remove vertical growth, upward or downward, which produce little to no fruit and interfere with light entering the canopy.
One of my favorite tools for cutting large limbs is a Sawzall with the appropriate pruning blade.
            I will offer pruning classes of fruit trees on Saturdays beginning in mid-December. Watch the newspaper or my blog for exact dates and locations.

Fertilizers: Pay for Convenience or Do-It-Yourself?

Q. What are the year-long fertilizer requirements for landscape plants ranging from acid loving to desert lovers such as cacti, palms and other plants to beautify home landscapes.
Many cactus lovers swear byproducts such as cactus juice but most cacti do quite well with a variety of different types of fertilizers
A. Desert gardening and horticulture is more difficult to practice than traditional horticulture talked about on most blogs, information sheets, YouTube videos, books and other places. Most information in the media is derived from “traditional horticulture” and these practices may or may not work in the desert.
This powdered fertilizer meant for dry or liquid applications has combined fertilizers that create more acidity than some other types. But it has other fertilizers in it as well good for acid loving plants.
            When applying fertilizers to landscapes in desert climates and soils, consider soil improvement and irrigation beforehand. Soil improvement, where and when needed, solves many fertilizer issues.
A good citrus fertilizer that can be mimicked by combining other fertilizers less expensive. But it's convenience and knowledge that make the sale for most homeowners.
            The biggest mistake made by desert horticulturists and gardeners is a lack of soil improvement to desert soils when and where needed. Desert soil improvement solves 90% of the fertilizer and irrigation issues in residential landscapes. Because the majority of plants grown in desert landscapes are NOT desert plants.
Compost is a great all around fertilizer for most plants. It contains dozens of different minerals and elements not found in commercial fertilizers. Besides that, good compost is biologically active and help stimulate microorganisms better than commercial fertilizers.
            Spend more money and effort on improving the soil than buying and applying specialty fertilizers. Improving the soil and using organic surface mulches around non-desert plants reduces the need for chemical soil amendments, fertilizer applications and pesticides.
Called a starter fertilizer because it is high in phosphorus, the middle number. Excellent fertilizer when planting for the first time or seeding in the garden. You can mimic this fertilizer and save a little bit of money but is it worth it?
            With proper soil improvement, here are my recommendations for fertilizer applications, either conventional or organic:
·        nitrogen and potassium is needed by all plants on a regular basis
·        apply phosphorous fertilizers when planting: seed, transplants from containers or bare root, rhizomes, bulbs or any plant just getting started
·        plants grown for their flowers or fruit require at least one fertilizer application of nitrogen plus phosphorus during the growing season and applied 2 weeks before flowering and fruiting
·        fertilize vegetables and annual flowers monthly; lawns every 8 weeks
·        fertilize prized landscape plants more often than “ordinary” landscape plants
·        use specialty fertilizers on rare occasions for very specific reasons

Are Pears with Corky Spot Edible?

Q. I was reading your blog about the brown spots in the flesh of pears. Is fruit with these spots edible?
Keiffer pear with outside evidence of Corky spot With the small green dimple in the center of the fruit
A. Corky spot in pears appears as brown areas, about the size of a small marble or smaller, in the flesh of the fruit. These spots are surrounded by healthy flesh. On the outside skin it is hard to see but often it is slightly sunken and frequently some green remains after the fruit ripens.
            The flesh is not rotten. The cells in the flesh do not have enough calcium for good development and they die and are brown. These spots do not taste good and are usually dry. But if you eat them it’s not a problem and will not harm you.
Corky spot on the interior flesh of Keiffer pear.
            My experience with this “disease” is that it develops on pears grown on older trees, usually over ten years of age. I theorize that the roots of the tree have exhausted the calcium in the soil surrounding them. The soil is full of calcium, but it cannot release it fast enough as the fruit develop.
Corky spot on Comice pear growing in the Mojave Desert

            What to do? Applications of calcium to the soil are not 100% effective. It is recommended that the fruit on the tree is sprayed with a liquid calcium solution as the fruit is enlarging. The most effective sprays are made with 5% calcium chloride dissolved in water. The calcium chloride should be food grade.
5% solution of Foodgrade calcium chloride will work as a foliar spray. This foodgrade calcium chloride is for homebrewing
            These spray applications are made five times, at least a week apart, as the fruit enlarges. Direct the sprays mostly at the fruit. Leaf sprays are less important.
            Not all pears are affected equally. Some pears appear to handle low soil calcium levels better than others. The problem may also vary with different types of soils. Watch for it on older pear trees.
            By the way, this disorder also affects some apples. When it does, it is no longer called “Corky Spot” but “Bitter Pit” instead.

Mojave Desert Six Pines Available

Q. I want to plant pine trees like I saw at the Hughes Center near Sands and Paradise. They have foliage near the ends of the branches and have a round shape rather than conical or a Christmas tree shape but I don’t know what they are.
Elderica or Mondel pine With its Christmas tree like shape
A. They might be attractive when they’re small, but most pine trees are large when mature, don’t fit in small to medium-sized landscapes and are not compatible (design-wise) with one to two-story homes. They might be fine for commercial landscapes and parks but not around homes on small residential lots in the desert.
Aleppo pine in its youth
            I think the trees you saw were still relatively young, 20 years or less, planted too close together and not given enough water. This is why they were round in shape with needles only at the ends of the branches.
            Pine tree availability at nurseries is somewhat limited compared to other parts of the country. I believe the pine tree you saw that interests you is an older Mondel or Afghan pine which becomes rounded as it matures and attains a height of 40+ feet.
Aleppo pine at maturity near parking lot
            Another commonly sold pine here is Aleppo which resembles Mondel pine in its youth. Both trees when younger are pyramidal or Christmas tree-like in shape. Mondel becomes more rounded with age and Aleppo pine becomes “gangly” and informal in shape. Aleppo pine can reach heights of 60 to 70 feet.
Japanese black pine with its very distinctive silhouette
            A third large pine planted here in the 1980s and making a comeback now is Chir or long-needled pine. It is a very graceful, pyramidal pine less tolerant of cold winter temperatures. All three of these large pine trees should not be used in small residential landscapes particularly with single-story homes.
Chir pine Which used to be called Pinus longifolia and you can see why because of its long needles. This pine tree fell out of disfavor during extremely cold winter where many of them were severely damaged or outright killed. It's making a comeback and a beautiful distinctive pine.
            So-called “smaller pines” may not actually be smaller when mature. Italian stone pine, a pine tree with a rounded shape all through its life, is a slow growing pine that may be acceptable in smaller residential landscapes for a number of years. However, it can reach 50 feet when mature. It can also provide edible pine nuts, the chef’s pignoli.

            Our state tree, single leaf pinion pine, would be a good choice for desert landscapes if you could find it. But it to can be large as well, 50 feet or more, when irrigated and given time. It also produces edible pine nuts.

            A pine tree popular with landscapers and architects over the years is the very distinctive Japanese black pine. It has been touted to be tolerant of alkaline soil but is a “specimen” pine with a unique shape that makes it popular in “designer landscapes”.
            However, I have never seen a Japanese black pine perform well here in our climate and soils. You see it used further north in arid states. further north in aired states You don’t find many older ones around town which may speak volumes about how well it is suited for our location.

Fruit Tree Leaves Okay on the Ground, Fruit Not

Q. We have fruit trees planted in an area we have covered with wood mulch. We always clean up the fallen fruit. Can we leave the fallen leaves on the ground or do they need to be cleaned up?

Western Box Elder bug ready to feed on dried apple still hanging on the tree, pecked by a bird. This insect feeds on decaying plant material but if it can get inside an old fruit through a bird peck, it will.
A. It is always a good idea to clean up fallen fruit because of pest problems. It is also very important to remove dead fruit from trees after harvesting.    
            I like to see fruit picked up from the orchard floor at least weekly. If you don't, it can lead to numerous insect and vertebrate pest problems. If you are composting this fruit, either bury it in the compost pile or put it in a sealed containers where pests can’t get to them.
This is a picture of the confused sap beetle on the University of California IPM website. Very common pest found in orchards where the old fruit is left on the ground or hanging on the trees. The simple control measure? Pick up fallen fruit from the orchard floor and dispose of it right away. http://ipm.ucanr.edu/PMG/r261300111.html
            One common insect problem with nearly all soft fruit when it’s ripe are fruit beetles. They get into decaying fruit on the orchard floor where their populations multiply rapidly. These beetles then infest soft mature fruit hanging on the tree waiting to become “tree ripened” or disposed fruit laying on top of the compost pile.
Picture of a pest of old fruit left on the ground or not removed from the trees, the dried fruit beetle. How to get them under control? Sanitation. Pick up fallen fruit and remove old fruit from trees. Fig fruit in particular is a big source of this problem. http://ipm.ucanr.edu/PMG/r261300111.html
            If this is a problem with your fruit trees, improve orchard sanitation by picking up fallen fruit and remove old and damaged fruit hanging from the trees.
An entry point for dried fruit beetle inside figs is the "eye" or hole at the bottom. Some figs have closed "eyes" and others are open. These rascals like the open ones so they can climb inside and cause havoc.
            Leaves from most fruit trees are not a problem if left on the ground to decompose. That's not true however in the vegetable garden and possibly other parts of the landscape. Leaves and stems will decompose much faster if they are chopped or shredded first.
            If it were me, I would shred leaves and stems and leave them on the orchard floor to decompose but not the fruit.

Think Twice Before Purchasing Timber Bamboo for a Residence

Q. A local nursery has timber bamboo available-for-sale. How far from a brick wall should they be? How far apart should they be? Should they go on a planter box? Do I need a barrier for the roots?

Timber bamboo at a residence kept under control

A. I have giant timber bamboo growing on our family farm in the Philippines. They grow close to a small stream of water bordering our large farm property.

            In the tropics, they are quite useful for construction. I am less enthusiastic about them for smaller residential properties. I am even less enthusiastic about them for the desert. Put them in parks or large commercial properties where water is cheap.
Bamboo is probably the most utilized plant for different construction purposes in the world. It is highly versatile.

            You need lots of room to grow timber bamboo. Bamboo is in two basic categories; clumping and running. Most of the cold weather bamboo are running which means they spread underground several feet before they pop out.

            Clumping bamboo has very short underground rhizomes so they pop out very close to the mother plant. Clumping bamboo is preferred for residential properties. Timber bamboo is clumping. But hold on.

            Timber bamboo is massive and extremely powerful. It will heave walls, driveways, patios easily. They require very large amounts of water that’s why ours grows next to a small stream.

Timber bamboo planted in Las Vegas Nevada near the back wall of an apartment property. I took this shot several years ago. It is probably gone because of destruction to the wall and the parking lot. It should not be planted in small spaces.
            Timber bamboo comes in several species and there are some very cold hardy ones that can easily handle our winter temperatures. That is not what I’m concerned about. I am concerned about how aggressive they are.

            In the tropics they can grow to seventy or 80 feet tall. In the desert they will be considerably shorter because of the low humidity, high temperatures and lack of available water unless you are flooding them.
            These plants will become a nuisance in about 3 to 4 years after planting. You will have to stay on top of them and remove suckers and keep the underground rhizomes in check. I would not use them in the desert.

             If you decide to plant them, I would give at least a 5 foot “no grow” area surrounding them. This means you should remove “suckers” coming from the rhizomes that pop up in this area. That will help to control it spread somewhat.
Close-up of the same plant and you can see how it spreading underground by short rhizomes producing "culms" or suckers.
            I would plant them no closer than 15 feet apart and expect them to grow to 40 feet in height. The clumps will grow larger in diameter over the years.
Sometimes called heavenly bamboo, it is not even closely related to bamboo. This is Nandina domestica poorly managed.
           You will not control them with shallow root barriers. Use root barriers are at least 2 feet deep. Their roots and rhizomes are shallow but a 1 foot deep root barrier will not be enough to keep them contained. Install root barriers after three or four years. An option is to trench around the clump every 2 to 3 years, cut the rhizomes and remove them.
           Expect to increase your budget for water.If given enough water, they are extremely fast growers.