Question: How can I inexpensively amend clay soil?
Answer: All soils can be prepared the same way. First, scrape away any existing weeds and grass, and toss that material into a compost pile or replant the sod elsewhere. Always remove the grass before tilling — otherwise, you’ll drive the reproductive parts into the ground to be weed problems forever. Organic herbicides can be used in summer, but physical removal is best.
Raise the beds. Walls aren’t essential, but the top of the beds should be flat and higher than the surrounding grades, with sloped edges for drainage. This lifting will happen naturally if proper amounts of amendments are added to the existing soil.
Add amendments. Use compost (4 to 6 inches), organic fertilizer (2 pounds per 100 square feet), lava sand (10 pounds per 100 square feet), greensand or other rock minerals (4 pounds per 100 square feet), and whole ground cornmeal (2 pounds per 100 square feet). Rototill or fork amendments to a total depth of 8 inches.
Moisten beds before planting. Dry soil will dehydrate young roots as they grow.
Plant high. Remove excess soil to make sure plant flares are uncovered. Set plants high, with the top of the rootballs slightly higher than the surrounding soil, and flares dramatically high and visible. This is especially critical for woody plants. Setting plants too low can cause poor growth or drowning.
Mulch beds. Add 2 to 3 inches of organic mulch after planting. Use shredded native tree trimmings for large plants and a thinner layer of compost for annuals and perennials. Never pile mulch onto the stems of plants.
-Howard Garrett, AKA “The Dirt Doctor”
If you’d like to present a question for our expert panel to answer in print, email your question to Letters@HeirloomGardener.com with the subject line “sage advice.”