Gardening : White, Spotty Fungus Plagues Crape Myrtle
QUESTION: I have a dwarf crape myrtle that gets a white, spotty fungus on the leaves during summer. What do you suggest I put on it?
ANSWER: As beautiful as they are, some crape myrtle selections are plagued with “powdery mildew,†a fungal disease that distorts and discolors the leaves, covering them with a distinguishing whitish powder.
Early morning watering, thoroughly drenching the leaves, discourages the development of mildew. Following this practice, you can just ignore the little bit of mildew that may show up from time to time, because it is not very serious. Some folks like to apply sulfur to control mildew, but to me the visual appearance of the sulfur is no better than the look of the mildew. It is best to plant mildew-resistant selections and to locate them in full sun where there is good air circulation.
However, if you already have susceptible plants, and the mildew tends to become pronounced or distracting, you might spray every 7 to 10 days during the growing season (before the infection becomes severe) with benomyl (Benlate) at the rate of one-half tablespoon per gallon of water. Although tell-tale signs will remain on older foliage, this will keep the fungus from starting on newer leaves. (These same procedures also work well on roses.)
Thinning Peach Tree Will Enhance Harvest
Q: My peach tree looks like it is loaded with fruit this year. My neighbor says I should thin it, but if I pick off the little fruits, won’t it reduce the harvest?
A: Thinning was a hard concept for me to accept in my youth. When I first actually did it, I felt horrible, because there was literally more fruit on the ground than there was on the tree. I worried and fretted about it for a couple of months--until I saw these wonderful, huge fruits ripening all over the tree.
In spite of the numbers I had eliminated there was still more fruit than I could use, and almost every fruit was big and especially delicious. Without thinning, there were always lots of fruits, but most of them were small and tasteless (and the weight of their numbers often broke branches).
Before the fruits reach the size of the last joint on your little finger, pick off all but about two in every 8 inches. It will make a marvelous difference in the quality of the fruit you harvest this summer.
Nasturtiums Are Easy to Grow and Tasty
Q: What can you tell me about nasturtiums? Someone said you can eat the flowers. It sounds fun, but is it true? Do they grow around here? Do they require any special care?
A: Nasturtiums are very easy to grow, and, yes, the flowers, leaves and unripe seed pods are completely edible. They have a wonderful peppery taste, like watercress; and the two-inch yellow, orange or reddish blooms add character to a salad. (Just be careful, if you wish to eat them, that you do not feed any surrounding plants with a plant food that contains systemic insecticide.)
I have grown Nasturtiums under my rose bushes for several years: They make an attractive high ground cover and space filler. And they bloom throughout the spring, summer and fall, usually dying in the winter. Sometimes they even reseed themselves. We enjoy them.
Seeds are readily available and are inexpensive. They do best in sandy soils and need no special treatment. In fact, they don’t even require any feeding in most soils. As long as they have adequate moisture in a well-drained soil, and full sun or only partial shade, nasturtiums will thrive.
Green Leaves Grow on Purple Leaf Plum Tree
Q: I planted a purple leaf plum tree, and this spring half of the tree has the normal purple leaves, but half has green leaves. Do these trees revert to green after a while, or is there something I can do to get the whole tree purple again?
A: Purple leaf plum trees are quite stable: They do not revert to green from above the graft. However, they are traditionally grafted onto normal green plum roots, and sometimes a “sucker†arises from these roots.
If you look carefully at your tree, I’m sure you’ll find that it has two trunks now. The original purple leaf plum trunk still has the normal purple leaves; but the newer trunk--arising from the roots or somewhere else below the graft--produces green leaves.
It is necessary to remove this green-leaf trunk completely. Dig into the soil to determine where it starts, and with sharp clippers or a hatchet cut it out, being sure not to leave any stub which could sprout new suckers. Watch the tree carefully this summer to see if any new suckers come up; remove them at their point of origin as soon as they appear.
If you allow sucker sprouts to remain on any grafted tree or plant, they will eventually take over, and the grafted part (in this case, the purple leaf plum) will die out.
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LILAC LOVERS: Our lilacs have been glorious this year, just full of those wonderfully fragrant lavender blooms; and because it remained a little cooler during blooming time than we often experience, the flowers lasted for several weeks.
While many lilacs require really cold winters in order to bloom properly, Descanso Gardens of La Canada has developed and introduced a few strains that are perfectly suited to our Southern California valleys. The most popular and most readily available is called “Lavender Lady.â€
Lilacs normally should not be pruned too much--doing so will reduce the quantity of next season’s blooms. But dead and weak branches can be cut out along with spent flower clusters (trimmed just above newly emerging leaf buds) as soon as the old blossoms fade away.
Roses are glorious this spring. For easy-care instructions to help you get great roses with a minimum of trouble, order my special video, “The Care and Pruning of Your Roses.†Send a check or money order for $18.99 (made out to Jack Christensen) to Rose Care Video, P.O. Box 1231, Ontario, Calif. 91762-0231. Allow 2-3 weeks for delivery.
