Fall and spring are best times to plant

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?

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.

The second-best time for planting is 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.

Make sure 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 won’t have a problem.

During planting, make sure to water the amended soil around the roots during the time you are planting. After planting, water by hand for three consecutive days to make sure air pockets were removed around roots.

Construct a basin around the plants and hand-water them for the first two weeks before turning them over to drip irrigation.

Q: I was reading your blog about brown spots in the flesh of pears. Is fruit with these spots edible?

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’s hard to see, but the surface is slightly sunken over these areas 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 turn brown. These spots do not taste good and dry. But eating the fruit is not a problem and will not harm you.

It seems to me this disease develops on pears growing on older trees, usually more than 10 years of age. I theorize the roots have exhausted the calcium in the soil surrounding them. The soil is full of calcium but cannot release it fast enough as the fruit develops.

What to do? Applications of calcium to the soil are not 100 percent effective. The best alternative is to spray the tree with a liquid calcium solution as the fruit is enlarging.

The most effective spray is calcium chloride dissolved in water to make a 5 percent solution. The calcium chloride should be food-grade.

The tree is sprayed five times, at least a week apart, as its fruit enlarges. Sprays should be directed mostly at the fruit.

Not all pears are affected equally. Some pear varieties appear to handle low soil calcium levels better than others. The problem also varies with different types of soils. Watch for it on pear trees that produced fruit for several years.

By the way, this disorder also affects some types of apples. When it does, it is no longer called “corky spot” but “bitter pit” instead.

Q: What if I can’t make five consecutive weekly sprays to control brown spots on pear fruit? My problem pear is at a second home, and I am not there for five weeks at a time.

A: Five sprays, at least one week apart as the fruit is enlarging, is recommended. Apply it as many times on as you can as the fruit is enlarging and hope for the best.

If you can’t be there when fruit is enlarging, then expect a problem. You cannot spray the fruit only after it is large or very small and correct the problem.

Try substituting calcium fertilizers, such as calcium nitrate, during early spring applications of fertilizer. Try applying gypsum to the soil in early spring since it also contains calcium.

Organic approaches would be to apply organic-labeled gypsum, shells, dolomite or marl. These sources of calcium must be very finely ground, like flour, to be effective the same year it’s applied. Apply these to the soil two to three months before the fruit needs it.

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

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

In the tropics, timber bamboo is useful for construction and many other things. I am less enthusiastic about it planted in small residential properties. I am even less enthusiastic about it planted in the desert. Put timber bamboo in parks or large commercial properties if water is not expensive.

Lots of room is needed to grow timber bamboo. Bamboo comes in two basic categories: clumping and running types. Most cold-weather bamboo is the running type, which means stems grow underground several feet before they emerge from the ground.

Clumping bamboo has very short underground rhizomes, so they pop up very close to the mother plant. Clumping bamboo is preferred for residential properties. Timber bamboo is clumping.

But timber bamboo is massive and extremely powerful. It heaves walls, driveways and patios easily if planted too close to them. It requires very large amounts of water.

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 grow to 70 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 flood them on a regular basis.

These plants will become a nuisance in about three to four years after planting. Stay on top of them and remove suckers and keep the underground rhizomes in check. I would not use them in the desert because of their high water requirement.

If you decide to plant them, 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 their spread somewhat.

Plant them no closer than 15 feet apart and expect them to grow to at least 40 feet in height. You will not control them with shallow root barriers. Place root barriers at least 2 feet deep.

Q: My Seville orange tree has been growing in my yard for more than 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?

A: The reason upright limbs of fruit trees with large fruit become horizontal is from the weight of the fruit. The fruit tree that demonstrates this best is pomegranate.

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.

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, 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.

Bob Morris is a horticulture expert and professor emeritus at the University of Nevada, Las Vegas. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.