By Bodie Pennisi
University of Georgia
Here are a few suggestions that will help your annual garden turn into a colorful paradise.
Most annuals grow well in a variety of soil types, as long as the soil holds enough moisture and drains well. Amend heavy soils with sand, perlite or coarse bark to improve drainage.
If you must use a poorly drained area, build raised beds. Do this by digging furrows along the sides of the bed and adding the soil to the bed top. Add topsoil and/or organic matter to further raise the bed. Excess water can seep from the bed into the furrows.
With average garden soil, use a 1 to 2-inch layer of organic matter and a 1-inch layer of coarse, unwashed sand. Use twice as much organic matter and clay if your soil is heavy clay. And don't add any sand to the sandy soil of southern Georgia.
Below-average soilPoor subsoil can be made into good garden soil by adding organic matter and sand each year. Peat moss, pine bark, compost, leaf mold and well-decomposed, stable manure are all good sources of organic matter.
Instead of burning leaves in the fall, turn them into your flowerbed as organic matter.
Have the soil tested. A pH of 6.0 to 6.8 is satisfactory for most annuals. Most Georgia soils are acid, and you have to add lime to raise the pH. In the absence of a soil test, add a complete fertilizer, such as 10-10-10, at 1 pound per 100 square feet.
Annuals seeded in the garden often don't germinate properly because the surface of the soil crusts and cakes, which doesn't allow water to penetrate into the soil.
Planting trickYou can prevent this crusting by sowing seeds in 1.5-inch-deep furrows filled with vermiculite. Make another shallow furrow in the vermiculite and sow the seeds at the rate recommended on the seed package. Cover the seeds with a layer of vermiculite.
At planting, pinch the flowers and existing flower buds to encourage more vigorous vegetative growth. Removing the flowers and/or the tip growth allows the roots to develop faster. In transplanting annuals, plant the seedlings no deeper than they grew originally.
During the growing season, plan to apply 1 inch of water each week when it doesn't rain. When you water, moisten the entire bed thoroughly. Don't water so much, though, that the soil becomes soggy. Allow the soil to become moderately dry before watering again. A soaker hose is an excellent way of water beds.
Don't forget mulchGood mulch materials include pine straw, pine bark and slightly decomposed leaves. You can spread sheets of ground cloth or weed barrier over the soil surface, too, and cover it with organic mulch.
Use only decomposed organic material as a soil amendment and only loose organic matter as a mulch cover.
Fertilize established plants at 1 pound of nitrogen per 1,000 square feet. Plants take up nitrogen actively from April or May until September. Use general-purpose fertilizer, such as 10-10-10 or 16-4-8.
You can use slow-release fertilizer, organic or liquid. During hot weather, use high-nitrate fertilizer such as 15-2-20. During cool weather, use balanced ammoniacal/nitrate fertilizers such as 20-10-20.
(Bodie Pennisi is an Extension Service horticulturist with the University of Georgia College of Agricultural and Environmental Sciences.)