Non-fruiting cherry trees
How you should pronounce Fuchsia
How diseases affect the Garden
Planting near water-lines
Sun-fried Sambucus nigra 'Black Lace'
Question: My sweet cherry tree has produced no fruit the last two years, though it had a few tasty cherries the year I planted it. Is there some special fertilizer I should be using? Could the ants I've seen on it be causing a problem?
Answer: The ants are not your problem. If anything, your problem may be a shortage of insects. Cherries depend on insects for pollination. An assortment of bees, both the introduced honeybee and a range of native ones, some of them solitary, typically perform this vital work. In recent years the populations of these bees have been declining. The improper application of pesticides during bloom time can make this bad situation even worse.
In addition, your tree may require cross-pollination. Sour cherries are self-fertile, but most sweet cherries require another cultivar nearby for cross-pollination. This cannot be just any cultivar, but one specifically selected for compatibility and time of bloom. You can find good compatibility charts on the Web sites of Penn State http://ssfruit.cas.psu.edu/215.htm and Michigan State extension http://www.maes.msu.edu/mwmihort/bloomchart01.pdf. You will also see on those pages that there are some varieties of sweet cherries that are self-fertile and will not require a pollinator, and these self-fertile varieties might also serve as pollenizers for your tree.
Finally, bad weather may also be responsible, especially with sweet cherry, which blooms earlier than sour cherry and can be hurt by freezing temperatures. Rainy weather can also reduce fruit set.
Fertilizer recommendations vary with soil types, age of tree, and other factors. It is best to get a soil test but generally you would be safe to apply 5-10-10 fertilizer, a half pound for each year of the tree's age. (For example, you would give a four-year-old tree two pounds.) Less is better than more, since over-fertilization can damage roots and promote too much vegetative growth at the expense of fruit production. Never fertilize any fruit tree the year you plant it.
Question: All my life I have pronounced Fuchsia as FYOO-shah, as has everyone else I know. Recently, the pronunciation guide in Horticulture stated that FOOK-see-ah is the preferred pronunciation. Why?
Answer: Tom Fischer, who writes the pronunciation guide for Horticulture (see page 78) is entirely correct. Fuchsia is actually named after 16th-century German botanist Leonhart Fuchs, and the word should be pronounced as one would pronounce his last name. However, this is one of those cases where the incorrect pronunciation has gained such wide acceptance that if you were to say "FOOK-see-ah" in all but the most erudite gardening circles, listeners would think you were some sort of novice.
There are multiple examples of this in botanical nomenclature. Each spring, the bright yellow blooms of forsythia brighten the landscape. You'd raise eyebrows if you pronounced it properly. It was named for William Forsyth and should be spoken with a long i (as in ice).
Heuchera, named after Johann Heinrich Heucher, is properly pronounced "HOY-ker-uh." We mastered Kniphofia, the red hot poker named for J. H. Kniphof, as "Nih-FO-fee-ah," but it should keep its hard k and be spoken "kuh-nip-HOFF-ee-ah." How do you like them alphabets?
In one sense, it's a shame that the plant names meant to honor these individuals have lost their original flavor, but it is difficult to explain to those puzzled faces why you insist on pronouncing the name differently than everyone else. When you stop to do it, you are paying homage to these plant pioneers. Still, most of the time it's just easier to go along with the widely accepted version, which Tom Fischer has begun to note in our guide.
Question: There seems to be some sort of disease in the upper part of my garden. I see whole branches of my groundcover junipers dying, followed by the whole plant. There are spots and sometimes whole brown leaves on my iris. The kousa dogwoods also dropped leaves and one of them died. Is this going to spread and kill all my plants?
Answer: It is easy to assume that a single infectious organism is the cause when many plants in a particular area are having problems. However, diseases and insects typically attack a specific group of plants, such as the members of one family. When you see a group of unrelated plants declining, it is unlikely that you are dealing with any one disease.
More likely your plants are declining because of an environmental factor. If yours is a newly established landscape your plants may have been planted improperly. Perhaps they were overfertilized at planting, or they are being watered incorrectly. Is the soil poorly drained? The symptoms described could all be linked to saturated ground. Diseases may be the culprit, but they are likely to be a variety of different ones that find the environmental conditions, such as too much shade or too much moisture, to their liking.
Plant health diagnosis is detective work. It may require professional assistance. Most county extension offices are now set up to do long-distance diagnostics-meaning that digital photographs can be sent by e-mail to a pathologist who in turn can provide answers and advice over the phone or in a reply e-mail.
Question: I want to plant a Japanese maple and assorted shrubs where the water lines for my pool are buried. They are two to three feet underground. Are the plants' roots going to invade or rupture these lines?
Answer: Water lines, when properly jointed and watertight, will not be invaded by plant roots. Note the qualification "when properly jointed and watertight." Even if they are intact now, they may not be sometime in the future. For instance, drought may cause the soil to shrink, creating breaks and leaks in the lines. Clay-based soils are very prone to this, whereas sand-based ones are less so.
Common sense dictates that there will probably come a day when you will need to dig up those pipes anyway. If you can plant in such a way that the tree and shrubs do not sit directly over the lines, so that you could dig down to the pipes without disturbing the plants, you should do so. If you think your pipes may spring leaks, you probably shouldn't plant close to them at all.
Information and maps of soil types state by state can be obtained through the Natural Resource Conservation Agency
Question: I fell for the frilly black foliage of Sambucus nigra 'Black Lace', and purchased two of these elderberry shrubs last year. They went from frilly to fried by the end of the summer, though they did begin to put leaves out in the fall. What did I do wrong?
Answer: The new elderberries on the market are very seductive. Reading about them makes one drool, as do the fabulous photographs. Information on their foibles is less visible.
There are several species of elderberry. The cultivar 'Black Lace' is Sambucus nigra, of European origin, and best suited to cooler regions. Our Native American elder, S. Canadensis, tolerates even hot summers.
Proper siting is especially important with these plants. In the wild, elderberries are usually found at the edge of streams or in rich bottomland and often grow in partial shade. Though the plant tag may claim that this cultivar can be grown in full sun and will tolerate drought once established, such conditions are less than ideal-especially in your climate. Elderberries dislike the dry, windy sites and poor soils with which many Oklahoma gardeners must contend. For best performance, give them moist, humus-rich sites and even some afternoon shade. Too much shade, however, will cause a loss of the purple leaf color.
Sambucus nigra also has a different growth habit than our American elder, which is a multistemmed suckering shrub. In S. nigra, plants are usually single stemmed. They may need repeated pinching in the first year to develop into a fuller shrub.
You also may wish to check the leaves closely if you see them beginning to lose vigor in the future. According to gardeners at the Missouri Botanical Garden in St. Louis, this plant can suffer from both spider mite and powdery mildew. An early diagnosis and prompt treatment may save your black frills.
For spider mites, you can use Floramite, Forbid, Avid, horticultural oil, or insecticidal soap. A cooler site and plentiful water may prevent spider mites from getting established. It also helps if you wash the dust off the plants periodically during hot, dry periods.
For powdery mildew, neem oil or horticultural oil can provide relief, as can sulfur during cool weather. Or turn to the fungicide myclobutanil (Immunox) or chlorothalonil. Better light and air circulation will reduce the incidence of powdery mildew. Since this European elderberry dislikes excess sun and wind, you may discover that it is a challenge finding the perfect location.