Answer #1 ·
Gardenality.com's Answer · Hi Clancey - I can definitely identify with the red clay soil drainage issue. Have been dealing with it for years here in the Atlanta area in my own landscapes and in our clients landscapes. Depending on what you are planting, there are different ways to go about planting in or on heavy clay soil and for improving drainage.
If it's very dense and "icky" clay soil, sometimes it's very difficult to condition it properly to plant vegetables, flowers, shrubs trees or a lawn because it's so hard to bust up into smaller pieces or particles that roots have these plants can penetrate. That being said, when the clay is drier, a layer of 3 to 6 inches top soil or soil conditioner can be tilled in with a roto-tiller to a depth of 6 to 12 inches to condition the clay. Sounds like you might have already done this? Even then, if the lay of the land is such that lower-lying areas in the landscape are not draining well, no amount of good organic matter or soil tilled into the clay soil will do what might be required to improve the overall drainage. In this case the land may have to be graded in a way to improve drainage. Or, if regrading is impossible, some type of drainage system might need to be installed.
Another option is to build raised beds or raised mounds. Some folks call them "berms." These work especially well for shrubs, perennials, annual flowerbeds and vegetable gardens. Creating these is just a matter of bringing in a good topsoil or "woods dirt" and mounding it on top of the clay soil to a height from 1 foot to several feet in height. Many plants grow better in raised/mounded beds because there's always good drainage. Just make sure when your doing raised beds to order good screened top soil and not "fill dirt." Also make sure that the contractor you hire can guarantee good drainage around the mounded areas. I would never hire grading contractor to do work for for me unless they used a laser transit to insure proper grade for good drainage.
Let us know if you need more details or if you have any other questions.
Brent)