Above, proof of the adage that you grow the soil not the plants. On the left a vigorous eggplant growing in high-end potting soil in a self-watering container. On the right a spindly, nitrogen starved specimen of the same variety of eggplant, planted at the same time, in our parkway garden. The container eggplant on the left is larger, has greener leaves and is obviously more healthy. The stunted eggplant on the right is the victim of depleted soil.
There’s some irony here. With our book release and press folks coming around to see things we’ve been doing too much planting and not paying enough attention to soil quality. Here’s two options we should have taken to help out that sickly eggplant in the raised bed (other than the expensive route of new potting soil):
1. Sheet Mulch
A concept from the permacultural toolbox, sheet mulching involves making a soil boosting lasagna consisting of a layer of compost or manure, newspaper to hold in moisture, and a thick application of mulch consisting of hay, stable bedding, or other bulk materials. Full instructions here via Agroforestry.net. See Toby Hemenway’s introductory permaculture guide Gaia’s Garden for a similar sheet mulching technique.
2. Cover Crop
An alternate soil building method would have been to simply give the beds a rest for a season and plant a nutrient-building and soil-busting mix of clovers and legumes. Peaceful Valley Farm and Garden Supply has a nice selection of annual cover crops here. We used their dryland mix to deal with the bad soil in our front yard and we’ll re-sow it again this fall. Cover crops send down roots that break up soil, with the legumes used to fix nitrogen–it’s a great way to amend a large area with almost no work involved.
Here at Homegrown Evolution we don’t believe in tilling soil. Tilling soil disrupts the natural balance of soil microbes and minerals and requires hard physical labor, thus interfering with other important activities such as cocktail hours and general laying about. It’s better to let nature do the work for you. Both sheet mulching and cover crops mimic the way forests and chaparral ecosystems take care of themselves. In natural settings, leaves fall and stay in place (no ‘mow and blow’ guys in the forest!) and weeds do the tilling.