When you buy a container shrub and plant it in your yard, you think it's suddenly a landscape plant. But it's not.
"It's still a container plant for the first few weeks," said University of Georgia horticulturist Jim Midcap. "Or at least you have to treat it as one."
Midcap, an Extension Service specialist with the UGA College of Agricultural and Environmental Sciences, said you have to remember how that plant has spent the first part of its life.
"Container plants are grown in nurseries in a mixture of bark and sand," he said. "That's because those mixtures drain so well."
The fast-draining mixtures help nurseries avoid the root rot problems they might have if they used potting soils that hold moisture better.
The only problem is that the bark-sand mixtures also dry out quickly. "And once the mixture gets really dry, the bark is hard to get wet again," Midcap said.
With many yards already dry, that could prove disastrous if long-range forecasts of a dry spring and summer are borne out.
Dry Root Ball Hard to Rewet
"If you let the root ball dry out," Midcap said, "you may think you're watering enough, but because the bark is so hard to rewet, the plant really isn't getting enough moisture to survive."
For the first four to six weeks, he said, all of the plants' roots are still in that original potting mixture. "That's what you need to water as if it were still in the container," Midcap said.
Most people know to water newly planted shrubs often. But they don't realize how critical it is.
Bark Dries Fast
"On very warm or windy days, the original bark mixture can dry out thoroughly in 24 to 48 hours, even though the backfill soil around it stays wet," Midcap said.
If you buy a container plant and delay planting it, be sure to water it several times a week, he said. Water it two to three straight times before planting. Make sure the root ball is thoroughly soaked.
If the root ball still feels dry, he said, soak it in a bucket for a while just before planting. Don't plant it if the root ball is dry.
Keep Potting Mix Exposed
When you plant a container shrub in a clay soil, Midcap said, keep the top of the potting mix exposed.
"If you cover it with a clay soil, it can seal it up. So moisture can't get into that sand-bark mixture," he said.
Keep watering it two to three times a week for the first four to six weeks. Until the roots grow into the surrounding soil, the plant still depends for moisture on the bark-sand mixture in the root ball.
In sandy, well-draining soils, it's hard to water too much. But be careful not to overwater in clay soils and other areas that don't drain well, Midcap said. Overwatering in clay soils can kill plants just as surely as not watering at all.
Water often, he said, and direct the water to the root ball. Keep rewetting the sand-bark mixture without overwetting the surrounding clay soil.
Dry, windy weather can dry out sand-bark potting mixtures fast and send your plants into a quick decline.
Don't Give Up on Plants
"Most plants start wilting first," Midcap said. But some -- hollies, for instance -- don't reveal moisture stress until their older, inside leaves begin yellowing.
If that happens, he said, don't give up on your plants.
"Get that root ball wet again and keep it watered properly," he said. "What happens when it dries out is that the root system shuts down, and then a little later the top begins showing stress.
"Give it enough water to make sure you get the root ball wet again," he said. "The plant will start regenerating absorbing roots to take up the water."
(Dan Rahn is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)