Tidewater Gardening - July 2008

Colors in July

by

K. Marc Teffeau

   It seems that we moved right from a cool, wet spring into the hot, humid summer with the 100+ degree temperatures in June. As we are in the middle of summer, I hope that this will not be one of those oppressive summers that we can get.
    By this time the annuals in the landscape need a little work. If you haven’t done so already, make sure that you dead head most annuals to keep them flowering. You don’t want the plant putting nutrients into seed production. If some of the annuals that you planted earlier in the season seem a little worse for wear, a little liquid fertilization will perk them up.
    Although we usually depend on annuals and summer flowering perennials to give us July color, there are a number of summer flowering shrubs that make a nice addition to the landscape. One of the most showy flowering shrub/small trees is the Crape Myrtle (Lagerstroemia indica). As one of the most drought and heat tolerant deciduous flowering shrubs, flower color can be white, pink, red, burgundy, lavender or purple and all shades in between. It flowers from July through September and plant size can range from 18 inches to 20 feet.
    The U.S. National Arboretum has released over 30 cultivars of this plant over the course of its breeding program. They have all been named after native American tribes and provide a wide range of colors and forms.
    When Crape Myrtles are mentioned, the most common image is one of an upright tall shrub or small tree. The National Arboretum introduced two neat miniature Crape Myrtles a few years ago under the cultivar names of “Pocomoke” and “Chicksaw”. These dwarf Crape Myrtles are excellent when used as small foundation or border plants, mass planting in beds, specimens in rock gardens or terraces, and even as container plants on the patio or deck.
For more information on these Crape Myrtles check out the National Arboretum website www.usna.usda.gov.
    Shrub Roses (Rosa species and hybrids) have become very popular in the last few years among gardeners. They are a carefree deciduous shrub that offers glorious color and are more disease and insect resistant than the hybrid tea roses. Colors available include many shades of white, pink, red, orange, yellow, burgundy, lavender and purple, as well as multi-colored flowers throughout the summer. Most shrub roses are 4-6 feet tall and wide.
    A family of shrub roses that have made a splash on the landscaping scene are Knock Out® Rose and Double Knock Out® rose series from Conard – Pyle. They are excellent shrubs to use as borders in the landscape. Colors include cherry red, pink, coral pink and white. Check out this group of rose selections at your local independent garden center or on the Web at http://www.theknockoutrose.com/index.cfm.
    A traditional summer flowering shrub that seems to have come back into favor is the Glossy Abelia (Abelia grandiflora). This is a great 5-6 foot tall and wide evergreen shrub with crème-colored, trumpet-shaped flowers all summer. Older cultivars have glossy, deep green leaves. ‘Sunrise’, a new hybrid, has variegated leaves that are a mix of bright gold and green.
    Althea or Rose-of-Sharon (Hibiscus syriacus) is a shrub in older gardens. I remember my grandmother having a row of them along the back yard garage. This plant is not one of my favorites but some gardeners like its rapid, upright growth that will reach 10-12 feet in height and 6 feet in width. Flower color is white with a burgundy eye, blue-purple, shades of purple or rose pink with a red eye. Blooming begins in June and continues until October.
    An excellent shrub if you have the room along a fence to let it get big is the Butterfly Bush (Buddleia davidii). It seems that there are more cultivars of this shrub than Carter has liver pills but a lot of people like it. It is an extremely carefree 8-10 foot tall and wide deciduous shrub that is perfect for providing a more naturalistic look. It can be easily sheared to a smaller size. Flowers are borne on long panicles in various shades of pink and purple from June through September. There is one pure white variety, ‘White Profusion’, and a new hybrid with yellow flower petals and an orange eye called ‘Sungold’.
    Look for some of the new dwarf cultivars of the butterfly bush. According to Spring Meadow Nursery in Michigan, the best dwarf plants come from a series called “The English Butterfly Series.” Developed by Elizabeth Keep from England, these plants are about half the size of a typical butterfly bush and very dense but have large flowers. Cultivars include Peacock, which is a nice lavender pink; Purple Emperor is a dark purple and Adonis Blue, is a rich dark blue. Another newly introduced series of miniature Butterfly bushes is the “Lo & Behold” series. The first release is Lo & Behold ‘Blue Chip’
    Vitex or Chaste Tree (Vitex angus-castus) is another deciduous shrub that grows well in our area. This 15-20 foot tall and wide shrub can be trimmed lower or limbed up into a small tree. It has a palmate, medium green leaf and delicate lilac and dark blue flowers in 5 to 7-inch long panicles. The flowers bloom in July and August.
    We tend to think of Spirea as a late spring flowering shrub with white flowers. Goldflame Spirea (Spiraea x bumalda ‘Goldflame’) is a 3 foot tall and wide deciduous shrub with changing colors throughout the season. It’s hard to believe most of its landscape color comes not from its prominent dark pink-purple June flowers, but from its red-bronze and yellow foliage in the spring and fall.
    Moving from ornamentals to vegetables - planning and planting the fall garden should be done now. Most folks consider vegetable gardening a spring and summer activity. With a little bit of attention and care, an excellent fall garden is possible in this area. In fact, many of our cool season crops such as broccoli, cauliflower and cabbage do better as a fall rather than a spring crop on the Eastern Shore.
    Start your broccoli, cabbage and cauliflower seeds now so you can set them out as fall transplants in August. It is difficult to locate fall vegetable transplants in this area as most greenhouse growers are oriented to the spring season. Mid to late July is a good time to direct seed lettuce, spinach, beets, carrots and turnips into the garden. They may be a little slow in germinating because of the high temperatures. Try lowering the soil temperatures by covering the seed bed with a floating row cover like “re-may” or some other shading material. Successive plantings of green beans can go in until the first of August. Wait until August for the fall planting of peas.
    July is the time when your bearded iris should be divided and replanted. Dig them up carefully and throw out the diseased and borer infested rhizomes. Separate the rhizomes and dust the cut ends with sulfur to reduce potential rot problems. Plant the iris with the top of the rhizome barely showing above the ground.
    Because the flower garden is in full bloom in mid-summer, July is a good time to evaluate its layout and note any changes that you might want to make for next year. You may want to combine colors or textures differently, change the location of some plants, or substitute different species. Get out the camera and take a few pictures of the plantings. Have the photographs available this fall or winter when you sit down to order new plants from the catalogues or plant next year’s flower display. Don’t forget that now is the time to order any spring flowering bulbs that you plan to plant this fall. Get your order in early to get the best selection and freshest bulbs for fall planting.
    July is the time when many independent retail garden outlets use a mid-summer clearance sale to empty their yards of plants left over from the spring season. In properly managed sales yards, when plants have been watered and fertilized and where insects and diseases have been controlled, plants are still in good condition. They will tolerate transplanting at this time of the year providing they are balled and burlapped or container grown. Do not attempt to transplant bare-root plant material now.
    Be careful about buying clearance plants at retail outlets where the sale of plants is a side income source and treated like a commodity like paper towels. Most of the time, little attention has been paid to the proper care of this material while on the lot. When selecting sale plants under these conditions, make certain that the plants are alive. Regardless of what the sales clerk tells you, horticultural scientists have not yet discovered a method of reviving dead plants.

   Happy Gardening!!