Some homeowners find it impossible to grow shrubs one year to the next. The stumbling block is summer. Up to Memorial Day, shrubs look superb, but then the roof caves in. By late July, the first signs of leaf or needle browning appear, and things go downhill from there. By Halloween, homeowners are digging up dead plants and swearing never to do it again. However, next April, new shrubs will be planted to try and break the hex.
If this scenario seems familiar, you may want to go out and celebrate the end of your bad luck skein. Buy a few of the discounted shrubs at the garden shop, make sure you're bringing home healthy stock, plant them according to the directions in this column two weeks' ago, then watch them survive in perfect health. The reason: Mites won't get to first base this summer.
The list of shrubs attacked by mites is long. The popular plants include arborvitae, azalea, boxwood, camelia, cotoneaster, euonymus, forsythia, hemlock, holly, honeysuckle, hydrangea, juniper, lantana, lilac, pieris japonica, pine, privet, pyracantha, rose, Russian olive, spirea, spruce, viburnum and yew.
In terms of host trees, they include all citrus plants, fig tree, fir, all flowering and fruiting fruit trees (flowering cherry, Bradford pear, flowering plum, almond, crab apple, quince and such), maple, mountain ash, oak, walnut and willow. Even English ivy and pachysandra are targets as are ageratum, aster, bamboo, begonia, carnation, clematis, cockscomb, coleus, columbine, cosmos, croton, dahlia, delphinium, fuchsia, gardenia and cape jasmine, gerbera, gladiola, gloxinia, heliotrope, iris, marigold, pansy, petunia, phlox, poinsettia, primrose, snapdragon, sunflower, sweetpea, verbena, violet and zinnia. House plants summering outdoors often are victimized by mites, including the rubber plant, schefflera, weeping fig and dracaena.
While there almost are a hundred species of mites, you need only be concerned with a handful, most of which have similar behavior patterns. The major ones are the broad mite (perennials and some indoor plants), cyclamen mite (attacking annuals/perennials), European red mite (fruit trees, roses and trees), spruce spider mite, and the two-spotted spider mite (the red mite). Seldom detected with the naked eye, mites are found easily with the aid of a quality magnifying glass.
Because mites rob sugar from leaves and needles, it is important to keep them under control. In cool, wet weather, mite populations usually are minimal. However, with the arrival of hot, dry conditions, the mite population grows to record levels. Most mites reproduce every 14 to 17 days, so a small infestation usually becomes all-out war over the month. By the time you see the damage, the plant is ready for the trash can.
If you have only a few shrubs, hosing down the plants with a fierce stream of water is sometimes enough to wash away the mites. However, you don't always succeed because most eggs are laid on the underside of leaves, and the hose can't reach them.
Your best hope is a methodical spray program beginning now and continuing through mid-September. Any chemical spray must be used in the early morning or evening when the temperature is below 80 degrees, and when there is no rain forecast for 24 hours. If you prefer spraying every 20 days, rely on Orthene at 1 1/2 tablespoons per gallon of water, but remember not to use it on crab apple, blue spruce, red or sugar maple. If you don't mind spraying every 10 days, choose from Kelthane (1 1/2 tablespoons per gallon), Spectracide (2 teaspoons) or liquid Dursban (1 teaspoon). Plants should be sprayed thoroughly for maximum protection.
Incidentally, symptoms of mite attacks vary. Most shrubs imply turn pale green, then brown. Often you find minuscule scratches on the leaves before they discolor. Bedding plant foliage turns silver before leaves drop.
A week early, the first brood of lacebugs has been reported on azaleas. Major pests up and down the coast, lacebugs are fully capable of decimating these shrubs before the summer is over. Eggs are laid in leaf tissue, after which foliage turns from green to gray. In advanced stages, you always will find pencil-size brown dots on the underside of leaves. For control, spray with liquid Cygon (2 teaspoons/gallon) now, again July 25 through Aug. 1, and a final spray between Sept. 5 and 10. Spray in the evening when temperatures dip under 80; azaleas should be dripping wet when you put the sprayer away. Leaves of rhododendron also are attacked by lacebug, so spray now and in late July.
While the roses last, save the good petals and remains of buds to make your own potpourri. Leaves must be in the peak of condition and dry, so gather in the afternoon. Petals from other flowers should be added, mostly verbena, pinks, gardenia and violets. Fragrance is the object, so add what you like. Dry indoors on paper towels or on a foil-covered cookie sheet in an upper oven where heat from the lower range will dry the petals in a week. Once bone dry, petals may be used for making potpourri. If you have a special recipe, send the full details to us at The Washington Post and we may include it in a future column.
If you've kept your fingernails from pruning the fuchsia since Mother's Day, look for the first flowers to be in place next week. Normally, your last pruning occurs May 10, after which flower buds develop and open five-plus weeks later. Hanging basket fuchsias thrive in morning sun, but shade from noon on. Pinch off flowers as they wither, keep soil lightly moist, and fertilize bi-weekly with 15-15-15 or 20-20-20; halt feeding at Labor Day since last buds will be in place before Sept. 20 (equal lengths of day and night), after which no buds will develop. Fuchsia can be kept indoors during the winter after the last petals fall.
If you have an overgrown rhododendron that needs trimming, here's how:
Decide approximate height you want canes cut back, then fold your fingers around the cane at that point and try to "feel" where there is or was a swelling on the cane. If canes are young, the swelling is visible, but on older canes, the swelling may have "grown over," making it difficult to detect but for the touch. Once you find the point of swelling, go a quarter-inch beyond the top of the swelling and cut through the cane with a saw. Repeat to other canes; Pruned-away parts cannot be rooted as cuttings, so discard; Fertilize rhody immediately with MiracleGro, RapidGro or Miracid, repeating about July 15 through 20 to promote new growth on which dormant buds will set in early September.