onditions which will increase transpiration or wilting. Do not place flowers in direct sun or drafts, or near hot radiators or electric lights. The use of flower preservatives in the water will extend the life of cut flowers. These materials contain sugars to provide nutrients, acids to prevent bacterial growth, and a fungicide to reduce the possibility of disease. The addition of aspirin or alum to the water will not help, and the use of salt may be harmful. Mashing woody stems will not increase water intake but may make it easier to insert such stems on a pinpoint. Square cut stems of herbaceous materials may be easier to hold on a pinpoint than those with a long slanting cut. Viburnums for Year Round Interest The next time additions are in order for the home landscape consider the benefits provided by viburnums. These plants are dependable and have interesting ornamental value for all seasons of the year. The special characteristics of many viburnums include fragrant white flowers in the spring, glossy green leaves during the summer, attractive autumn foliage and bright-colored fruits in late summer and fall. Viburnums are sturdy shrubs, which are easy to grow and most varieties are hardy in all parts of Virginia. Many viburnums are virtually pest free, though some of the snowball viburnums are occasionally attacked by aphids. Viburnums can be used as specimen shrubs, or in border plantings. Be sure to select an appropriate size for the location. Because of the many varieties of viburnums available ranging from very large to small, choose only those that fit space limitations. A large viburnum shrub, constantly pruned to fit a small space will never provide the expected effect. If properly located, the shrub should need only moderate pruning to retain a desirable form. Viburnums can also be used to attract wildlife such as birds and small mammals because of the abundance of fruit produced on each bush. Provide a well drained, fertile soil for viburnums. A mulch of wood chips or other organic material extending several feet from the base will conserve soil moisture and help suppress weed growth. On good soils, viburnums will make sufficient growth without fertilizer. If the growth is somewhat weak, or the foliage is light green, apply one cupful of 5-10-5 fertilizer around each medium size shrub. Use half this amount on small shrubs, and twice as much on large shrubs. Remember, use fertilizer only on weak growing shrubs planted on infertile soils. Consider some of the following species for planting in the home landscape. The Doublefile viburnum (V. plicatum tomentosum) is truly the most spectacular of the viburnum family. In mid May, large white non-fragrant flowers are produced in flat clusters, along horizontal branches somewhat like a dogwood. It grows eight feet tall with a slightly larger spread. In the fall the foliage changes to a bright red and is accompanied by attractive red fruit which gradually turn black. The dwarf doublefile cultivars, 'Mariesii' and 'Shasta,' which grow to about six feet, can give an effect equal to the larger species. The Korean Spice viburnum (V. carlesii) is a favorite because of its fragrant spring flowers. The white flowers emerge in late April to early May followed by red to black fruit from August to September. This dense shrub is usually rounded with stiff, upright spreading branches. It normally reaches a height of four to five feet with an equal to greater spread. The Wright virbunum (V. wrightii) is a medium size plant about eight feet tall. It has attractive flowers in the spring and an abundant crop of bright red berries from August until October. During October and November, the foliage turns crimson. The Witherod viburnum (V. cassinoides) reaches a height of six feet. This shrub produces an abundance of blooms in late June to early July followed by fruits which gradually change color from green to pink, then red to blue before becoming black in September. This characteristic makes witherod viburnum a good selection for high visibility gardens. The Tea viburnum (V. setigerum) is unusual because of its bright orange-colored fruits. It grows to a height of ten to twelve feet and has attractive white flowers in flat clusters in late May. Though the fruit is outstanding, the plant does tend to become leggy, and is best combined with other plants in the shrub border to hide bare bottom branches. A large tree-like viburnum to use as a specimen or in a mass planting is the Black haw (V. prunifolium). It grows fifteen feet tall and has attractive white flower clusters in mid May. In the fall shiny red leaves contrast with blue-black fruit. Low growing forms of viburnum are now available. The compact European Cranberry bush (V. opulus 'Compactum') grows only five feet tall, with good flower and fruit production even when young. A dwarf cultivar, (V. opulus 'Nanum'), seldom exceeds two feet and does not produce flowers or fruit. These low species are useful as hedge plants. There are many more varieties of viburnum. Visit a nursery or arboretum to find out about the viburnums that will perform well in your area. Shade Plants On the coldest days of winter our memories of gardening center on the sunniest spots. But as summer approaches we become interested in a shady garden for July and August. Fortunately, there are a number of plants that will not merely tolerate, but actually welcome, the cool dampness of a shady location. Coleus does well in a semi-shady location. The foliage of these popular plants can brighten the darker corners of your landscape with color. Easy-to-grow coleus can be started from cuttings or seed, so they make an excellent plant to share with friends. Another colorful foliage plant for shady locations is the caladium. Caladiums have very few pests and grow well in rich soil in semi-shade. Grown from bulbs, these plants are expensive but can add a variety of color to an otherwise uninteresting area. The variegated foliage may be crimson, scarlet, rose, yellow, white, or green. Wide variety makes them worth the investment for the right location. The best of the flowering annual shade lovers are the fibrous rooted begonias and impatiens. The selection of both of these plants has increased in recent years. Many of the most successful new hybrids have uniform growth habits such as flower size and plant height but have been bred in a wide range of colors so that you can select or blend colors to suit a particular theme. Additional plants for areas of partial shade are: Perennials: Tuberous Begonias (if bulbs are dug each year), Lobelia cardinalis, Primula (evening primrose) Biennials: Myosotis (forget-me-nots), Digitalis (foxglove), Bellis (English daisy), Dianthus (sweet william) Annuals: Malcomia (Virginian stock), Eschscholzia (California poppy), Lobularia (sweet alyssum), Nicotiana ( flowering tobacco), Viola (pansy), Vinca (periwinkle), Torenia, Balsam, Godetia, Mimulus (monkey flower), Nemophila, Wax Begonia Many of these shade plants have the added benefit of doing as well in containers as in the ground; so if you don't have a place for a shade garden, try a few plants in pots on the patio or even in a window box on the northeast side of the house. Siberian Iris Siberian or Beardless iris are among the easiest iris to grow. They have graceful foliage and dainty flowers, and bloom for about three to five weeks after the tall bearded irises in early to mid-summer. The blooms range in size from miniature to five inches in diameter on standard varieties. The leaves have a grass-like appearance and stay attractive all summer. Height varies from 20 to 48 inches with the average in the 30 to 36 inch range. The seed pods are also attractive and useful in dried flower arrangements. The color range of Siberian irises includes many shades of white, blue, violet, rose, yellow and bicolors. Among the recommended varieties of Siberian iris are Snow Crest, Blue Brilliant, Caesar's Brother, and Eric the Red. The Siberian iris has excellent value as a landscape plant. Virtually pest and disease free, they can be important as specimen plants as well as in massed plantings. Very tolerant of cold temperatures, Siberian irises can be grown in all parts of Virginia. These plants thrive in well-moistened areas and achieve their full height and good stem characteristics when grown in high moisture areas like those found near ponds. They prefer fertile soil that is adequately moist yet well drained. Fertilization should take place in early spring and after flowering. These iris have also been found to tolerate lime and heavy clay soils. Siberian iris flowers are ideal for arranging because they are so long lasting. Thriving in sun or shade, the plants are easily propagated by root division, either in early spring or in early fall. When dividing large clumps, separate them into groups of five or more leafing rhizomes or fans. Recent experience shows that the plants can be successfully transplanted in the spring and also after blooming season if adequate moisture is given until they are established. Before planting the divisions, make sure that the holes in which you will be putting them are large enough to spread out the fibrous roots for proper establishment. Adequate moisture is the key to growing Siberian irises well, whether in the field, garden or container. Spider Mites Spider mites are not insects; they are closely related to spiders, harvestmen (daddy longlegs), and ticks. Unlike insects which have six legs and three body parts, spider mites have eight legs and a one-piece body. They also lack wings, antennae, and compound eyes. Individual spider mites are almost microscopic, yet when they occur in large numbers, they can cause serious damage. Dozens of species attack shade trees, shrubs, and herbaceous plants. The two-spotted mite overwinters as an adult in the soil; the honeylocust mite overwinters as an adult in the bark crevices on the trunk and branches. Most other common species on trees and shrubs overwinter as tiny round eggs on leaves or bark. These eggs hatch in March or April. First-stage larvae have only six legs, but after molting, they become eight-legged nymphs. Both larvae and nymphs resemble the adults. Development time from egg to adult varies from 5 to 21 days depending on the species of mite and the weather. Many generations occur each year. Under optimal conditions, populations can build up very rapidly. Spider mites on conifers and broadleaved evergreens are cool weather pests. They feed heavily and reproduce quickly in spring and fall. Activity is low during the hot part of summer, although damage is often at a maximum and becomes easier to see when other plants are green and growing normally. Spider mites on honeylocust, linden, elm, willow, and oak are destructive in the summer. The two-spotted mite thrives whenever conditions are favorable for plant growth. Spider mites lack chewing or piercing sucking mouthparts. Instead they have a pair of needle-like structures called stylets which are used to rupture leaf cells. A feeding spider mite pushes its mouth into the torn tissue and draws up cell sap. Small patches of cells are killed, resulting in a stippling or fine flecking on the upper surface of leaves. On heavily infested plants, the foliage appears bronzed, bleached, yellow, or grey. Untreated, such plants lose vigor, become progressively weaker, and may eventually die. Spider mite damage to foliage is similar on all host plants: fine stippling which progresses to an overall bronzing of the leaves. With a hand lens, egg shells and cast skins are usually visible on the underside of damaged leaves. Mites can be observed by shaking infested leaves over a white piece of paper. The mites are about the size of the period at the end of this sentence. Spruce Mites are found only on conifers, hemlock, arborvitae, spruce, fir, juniper, and occasionally pine. A fine webbing which collects dust and dirt is produced on the foliage where they feed. Infested plants lose their color and the foliage becomes thin, because severly damaged needles drop prematurely. Most insecticides are not effective on mites and some result in increased mite damage by killing their natural enemies. Use a recommended miticide as listed in Virginia Tech's Pest Control Recommendations, call your local county or city Extension Agent. Always read the label before applying any pesticide. (Information provided by Eric Day, Manager of the Insect ID Lab, adapted from Insect Identification Laboratory Factsheet Number 5, by Daniel J. Hilburn, Department of Entomology, Virginia Tech.) -End- -Title- VA TECH HORT FACTS -State- Virginia, Va -Region- Southern, S -Doc- VA TECH HORT FACTS June 1987 The Virginia Gardener Question Box