North Mississippi Gardening Tips
June 2008
FLOWERS
Have you ever thought about selecting perennials for your garden based on their ability to attract beneficial insects? I bet you, like most gardeners, select these plants based on their flowers. Well, believe it or not, you can have pretty flowers and attract those beneficial insects, too. The “good” insects such as lady beetles, lacewings, syrphid flies, and tachinid flies prey on the “bad” insects including aphids, caterpillars, and mites. Usually the larvae feed on insects and mites while the adults feed on nectar and pollen; either exclusively or to supplement their diet when insects or mites are in short supply.
Some perennials that, according to research, will attract beneficials are Achillea filipendulina (fernleaf yarrow), Aurinia saxatilis (Basket of Gold), Tanacetum parthenium (feverfew), Sedum kamtschaticum (stonecrop), Solidago ‘Peter Pan’ (Peter Pan goldenrod), and Veronica spicata (spike speedwell).
Because the adults can feed on nectar and pollen your plan should be to have flowering perennials in bloom all season to keep the beneficials around. Of course, having blooming flowers all season is a goal of many gardeners anyway!
ROSES
This summer, when you go on vacation, I know visiting some gardens is probably on your wish list. Every gardener knows some of the best ideas we get come from “stealing” them from other gardens—some of us may be tempted to do more than “steal” ideas! I’m sure you are not one of them though. Public rose gardens in June can be gorgeous. Visiting one of these would be a great way to see roses that you have only glimpsed in catalogs and magazines. It is also a great way to see how particular varieties perform in our region. Mississippi has many, many private rose gardens and we also have a nice selection of public rose gardens as well. One of the newest is the Veterans Memorial Rose Garden on the campus of Mississippi State University in Starkville. Another is the rose garden at the Mississippi Agriculture Museum in Jackson.
If you happen to find a rose that you like in your local nursery. Go ahead and buy it, but you need to remember a few important things if you plant it this month. Even though container grown roses can be transplanted now, you really need to pay careful attention to watering and mulching. Newly transplanted roses do not have developed root systems in the existing soil so are more prone to drought and other stress conditions. These new additions to your landscape can be easily forgotten or overlooked as the summer wears on and you wear out! If you tend to be a neglectful gardener, it may be better to keep it in the pot and close by. Then plant your rose in the fall when weather becomes more favorable.
VEGETABLES AND HERBS
You can sow another round of sweet basil seeds for late summer if you enjoy using this herb in your cooking and you first crop has bloomed and become less productive. It is a great herb to use in any dish that contains tomatoes or a product from tomatoes—like catsup, tomato sauce, picante or spaghetti sauce. You can also sow seeds of summer crops such as beans, cucumbers, okra, pumpkins, southern peas, and squash for an early fall harvest. If you can find them you can set out transplants of pepper, tomatoes and sweet potato slips for a good fall harvest. To harvest basil you just snip off the leaves that you need. Don’t get over zealous and harvest more than one-third of the foliage at a time. If you can keep up with it, it is best to harvest beans, cucumbers, okra and squash every couple of days to keep plants producing. Pick most okra varieties when 2 to 4 inches long, yellow squash when 4 to 6 inches long, zucchini when 6-8 inches long, patty pan when 3 to 5 inches wide. Pick eggplant when the fruit is 3 to 5 inches long and the skin is still glossy. If the skin is dull the fruit is overripe. Dig onions when about one-half the top beings to turn yellow and flop over.
SHRUBS
June and July are ideal months to take semi-hardwood cuttings. Semi-hardwood is green growth than has begun to harden and turn brown. If you snap a twig the bark often clings to the stem. Some plants that can be propagated by semi-hardwood cuttings are camellia, banana shrub (Michelia figo) azalea, osmanthus, magnolia, nandina, coniferous evergreens like Japanese plum yew (Cephalotaxus spp.). For more information on this technique and other propagation methods call your county Extension office and ask for the Extension publication, “Propagating Plants for the Home Landscape,” Information Sheet 207.
For blue flowers on your French hydrangeas, maintain a soil pH between 5 and 5.5. Apply aluminum sulfate or sulfur to reduce the pH to this ideal range. Pink flowers occur on French or lacecap hydrangeas with a soil pH between 6 and 6.5. In this pH range, aluminum becomes tied up or unavailable in the soil and so is absent from the flowers. Use lime to increase the soil pH to this desirable range. If you want cultivars that tend to hold their color without being so persnickety about pH choose ‘All Summer Beauty,’ ‘Blue Wave,’ or ‘Nikko Blue’ for the blue flowers and ‘Forever Pink’ or ‘Pia’ for the pink flowers.
Lelia Scott Kelly, Ph.D., writes North Mississippi Gardening Tips monthly and is a Horticulture Specialist with the Mississippi State University Extension Service. Her office is in the North Mississippi Research & Extension Center, Verona.