|Our property has two areas of question: one concerning mosquito prevention, i.e. citronella plants what they look like and planting times; and two, the incorporation of winter color to our landscape (we've already ordered varigated red stem dogwood.) Your suggestions are welcome.|
|Most of the so-called mosquito plants look like and are treated like scented geraniums. These plants are long lived in warm climates but do not withstand cold winters, so you do have to bring it inside for the winter. Some gardeners opt to treat them like annuals and leave them outside where they freeze to death along with the traditional annuals such as petunias and marigolds. When planted in the ground for the summer these plants tend to grow larger and lusher than they would in a pot. Knowing this, some gardeners will plant them in the ground each spring, then in late summer take cutting or two to be wintered over in a pot and then use that as the replacement outdoors the following spring.
There are many shrubs that add winter interest to the landscape. Climbing hydrangea (Hydrangea anomala) is a vigorous, woody vine with beautiful exfoliating bark and an interesting shape. Another vine, sweet autumn clematis (Clematis terniflora), blooms in late summer and has flower parts that persist through winter. Kerria (Kerria japonica) is a little-used shrub that maintains its green twigs all winter, adding a little color to the landscape. Winter jasmine (Jasminum nudiflorum) is a shrub many people mistake for forsythia (Forsythia x intermedia) in the late winter landscape. From a distance, its yellow flowers are very similar. Bright green twigs and low, trailing growth habit are its greatest assets. The native witch hazel (Hamamelis virginiana) is a fall bloomer. I have always loved the understated beauty of its spidery, pale yellow flowers. This plant has been hybridized and many cultivars are available, adding to its appeal. The vernal witch hazel (H. vernalis) has many cultivars, as does H. x intermedia, a cross between the Chinese and Japanese varieties. These plants bloom in late January through March and display clear yellow to copper-colored flowers. This plant is very effective in a naturalized setting with native redbuds (Cercis canadensis) and flowering dogwood (Cornus florida). There are a large number of shrubs with berries that persist into the winter. The ones that come to mind quickly are the hollies. While not all hollies have berries, the blue hollies or Meserve hybrids (I. X meserveae) berry up nicely and are very popular. Chinese holly (I. cornuta) needs protection in the colder parts of the state and includes the popular cultivar ?Dwarf Burford?. Tree forms of holly include the cultivars Foster holly (I. X attenuata ?Fosteri?) and ?Nellie R. Stevens?. There is even a deciduous holly (I. verticillata) called winterberry for its bright red fruit that persist as long as the birds will allow. It is quite striking in the winter landscape. Other plants with berries that persist through the winter include northern bayberry (Myrica pensylvanica), a deciduous to semi-evergreen shrub with gray, waxy berries popular with migrating tree swallows, warblers and Baltimore orioles in the early spring. Pyracantha, or scarlet firethorn (Pyracantha coccinea), is a popular climber that is effective on buildings or arbors. The orange or red berries are profuse and persistent through the winter. Not all winter-interest shrubs have berries. The dogwood family has several species widely planted for their twig color. Tatarian dogwood (Cornus alba) and Red Osier dogwood (C. sericea) are effective in the winter landscape as their newest growth has a bright red color. There is even a yellow variety (C. sericea ?Flaviramea?). All of these plants should have one-third of their oldest twigs pruned out each spring for best twig color. Virginia is a diverse state and an amazing array of trees and shrubs can be grown here. Your local landscape company or garden center probably receives the annual ?Guide to Virginia Growers?, published by the Virginia Nursery and Landscape Association (VNLA). The 2006 guide is out and all the plants mentioned in this article are in it. Encourage your favorite nursery to buy from this guide and support Virginia agriculture.