The Right Soil For The Raised Bed
Garden tip from The Ground Up by Sal Gilbertie and Larry Sheehan
$19.99, paper, 256 pagesTen Speed Press
If you have a few yards of soil, a sheltered patio or even a sunny windowsill, Herb Gardening From The Ground Up will show you how to design, seed and nurture everyone’s favorite herbs from rosemary, parsley and cilantro to popular newcomers like lemongrass, plus new basils, garlics, sages and more.
Creating the right soil mix in the raised bed — soil, compost and peat moss in equal amounts, plus some perlite — means spending a little money at the garden center, feed store or nursery, but it will be worth the investment. For under $200, you can fill an 8-foot-by-8-foot area to a depth of 12 inches to 20 inches with the following plant-friendly ingredients:
- Topsoil (30 percent) as the basic growing medium for the herbs.
- Compost (30 percent) to provide the “breakfast of champions” nutrients for the herbs and to engender good tilth (or texture) in the soil.
- Peat moss (30 percent) to condition the mix by loosening the soil and blending with it. (You could use sphagnum moss instead of peat moss, but it is more expensive in some areas, and its coarser character makes it a bit harder to incorporate into the soil mix.)
- Perlite, crushed volcanic matter, or pumice (10 percent) to lighten the soil. (You could use vermiculite instead of perlite, but this cork-like matter derived from mica tens to retain moisture, which is not so good for most herbs, so I definitely favor the perlite.)
You may buy these materials if your soil is poor or claylike or if you’re constructing the garden on top of an existing lawn area. In the latter case, you should also be sure to break up the sod with a grub ax or spade and turn it grass-side down before filling in the area with topsoil, compost, peat moss and perlite.
Once these ingredients have been thoroughly blended with a spade fork, the soil should be tested for its degree of acidity or alkalanity.
Generally, most herbs do best in very slightly acid soil with a 6.0 to 6.5 pH reading. Dill, basil and parsley benefit in a slightly sweeter soil, but it’s not essential to add lime in those spots to get a decent crop.
Your Cooperative Extension Service will analyze a sample of your soil for a small fee.