By Paul A. Thomas
University of Georgia
Your colorful flower bed can use the barest minimum of water and still be the envy of the neighborhood. However, you'll have to upgrade the way you've been gardening a bit.
Step 1. There is no downside to adding organic matter to native soils. Try tilling in 4 to 6 inches of it and leveling the soil without compacting it. This will help the soil hold water without getting mushy in wet weather.
Step 2. Start with plants that don't require a lot of water. You'll save water. And you'll save yourself a lot of time in the garden.
Lantana, Celosia, Tithonia, Melampodium, Gomphrena, Dusty Miller, Vinca and old-timey petunias are some of the many annuals that, once established, require much less water than most. Avoid New Guinea impatiens, hybrid petunias, salvias, torenias, ageratums and marigolds.
Plant as early as you can, too, after the last chance of frost. The more cool weather annuals have to develop roots, the better they can withstand dry times.
Step 3. Use drip irrigation. With water dripping slowly rather than spraying out all over the place, the water savings are significant. It's efficient, because you put the water only where it's needed, and very little is lost to evaporation, assuming you cover the drip line with mulch. Compared to automated sprinkler systems, it's cheap, too.
It's not that hard to install, either. You need only some drip tape, several "y" adapters to take off drip lines from the main garden hose and the patience to spread the tape out just after you transplant your bedding plants. Most hardware stores, garden centers or irrigation supply dealers will have the hardware and will probably explain how to do this.
Step 4. Add more pine straw than you may have used in past years. If you hand-place the straw between the bedding plants so as not to cover them up, a 4- to 5-inch layer will greatly lower your water use. That much pine straw does two vital things.
First, it cuts down on the heat from the sun, allowing the soil to be several degrees cooler. This, in turn, lets the plants use less sugars at night, saving that food for more flowers and growth.
Second, it keeps the wind from pulling moisture out of the soil. Less heat and less wind means less evaporation. So the water you apply with drip irrigation lasts longer.
Step 5. Let the annuals dry out just a bit before watering. Don't water every day, or even every day you can during water restrictions. Let the plants work for their water by growing roots deeper in the ground.
Each time you water, irrigate long enough to saturate the soil thoroughly. Then let the entire bed go dry. Let the plants get to the point that the new growth begins to flag or droop in the afternoon.
As the plants get older and more established, this slight wilting will take many more days to happen than newly planted annuals. The bottom line is that you'll be watering less often, even as summer heat chugs on.
This procedure has worked well for commercial landscapers in Atlanta for the past 15 years. It has been proven to reduce water loss by as much as 30 percent.
It may take another hour to set up. But the reward is having beautiful flowers in dry, hot weather without spending your evenings after work watering your flower beds or sadly watching them perish in the heat.
(Paul Thomas is an Extension Service horticulturist with the University of Georgia College of Agricultural and Environmental Sciences.)