Every summer, blueberry lovers everywhere await the arrival of this sweet Georgia crop.Some of them, willing to pay a little extra, don’t wait that long.”Southern highbush blueberries ripen in April and May,” said Gerard Krewer, ahorticulturist with the University of Georgia Extension Service.Rabbiteye blueberries, the type grown most in Georgia, mature mostly in June and July.Georgia has around 4,000 acres of blueberries — more than any other Southern state.But only about 5 percent are the highbush type. So the blueberry supply is slim inApril and May. That makes prices high, on both domestic and export markets. It also makesthe lure of growing highbush berries strong.But Southern highbush blueberries don’t grow just anywhere.”They usually grow well only on certain soils that are high in organic matter buthave a well-drained topsoil,” Krewer said. “There’s only a very limited acreageof this type of soil in Georgia.”Growers with the more common soil types have found two options. One is to plant them insoil highly amended with peat moss or milled pine bark and mulched with four inches ofpine bark nuggets.The other method calls for planting directly into beds of four to six inches of milledpine bark. This high-density system is “very promising,” Krewer said.”Both methods work well,” he said, “but the plants have grown best whengrown directly in milled pine bark.”The high-density system calls for beds 30 feet wide with 10-foot aisles between them.The bushes are planted in rows across the beds, like the rungs of a ladder. Growers canspray down the rows of bushes from the aisles.Begun in Florida three years ago, the system requires daily watering. And since pinebark doesn’t hold nutrients well, growers must fertilize the beds every three to fourweeks during the growing season.The plants’ roots stay in the pine bark, Krewer said. But they don’t seem to blow downany worse than plants in soil. That’s apparently because they grow such dense mats ofintermingled roots.Southern highbush blueberry plants won’t do well if they’re too wet or too dry, hesaid. The pine bark system works well because there’s so much pine bark per plant — atnormal spacings, nearly 40 gallons per plant.”You can grow a mighty big plant in a 40-gallon pot,” Krewer said.Because the system is so much like a nursery, growers can plant even rooted cuttings inthe beds. And the plants grow fast.One grower near Valdosta, with just over an acre of high-density beds, grew plants fromrooted cuttings to bushes three to four feet high in about six months.The daily watering and narrow spacing present problems for southern highbush plants,since they’re susceptible to disease. Growers must use a regular program of fungicidesprays to keep the bushes healthy.Krewer said a small number of Georgia growers planted about nine acres of high-densityblueberries this year.It’s a costly system to put in — $10,000 per acre or more. But the returns comequicker than with other blueberry systems. Growers should begin harvesting berries inApril of the second year. They should get full harvests in the third year or fourth year.And they should get premium prices for their early-season harvests. The growing numberof people able to buy those early berries will figure it money well spent.