Say it with me now "OMMMMMMM." Drop the sound into your throat and say, "OMMMMMMMMMMMM." See how good you feel? That's the essential mantra of all human beings, the sound we make when all's right with the world. Perhaps ironically, the mantra for great soil is also OMMMM, in this case, short for Organic Matter.
First things first. Why do this at all? Why spend all that time and energy and often money to add compost, leaf mold, stable shavings, chicken manure, ground bark, or shredded paper to God's own dirt? Doesn't it grow enough plants for you already?
In a word, no, the native soil doesn't suffice for my garden; many of the plants I want to grow cannot be described as clay lovers. But I have more important reasons to amend the soil:
*to nourish and enrich the soil for continued cultivation. Look to history for the consequences of ignoring the importance of this tenet. Avoid the Dust Bowl effect by continually improving the soil you use.
*to compensate for the fact tha tmany suburban lots have no topsoil left. Some developers scrape it off with the trees and then truck in godknowswhat to level the site. As one friend discovered, you cannot grow a garden in asphalt.
*to increase microorganism activity and encourage more worms. The result of more worms is better tilth, the soil quality of balance between air, space, water, and solid materials. Better balance, better roots, better plants.
*to make native nutrients more readily available to plants. Clay is wonderful stuff, with ample levels of phosphorus and potassium as well as a host of minor elements like iron and magnesium essential for healthy plants. Organic matter improves soil chemistry to increase their availability.
*to phsyically rase the height of the planting area. Raised beds amended with organic matter warm up sooner and drain better than native soil beds.
Here's a few things you should know about organic matter: Larger pieces take longer to decompose in the soil, but smaller sizes attach readily to clay, so use a combination. Manures, gin trash, compost, and stable shavings differ in nutrients available to your plants. Bagged products should state their analysis, but generally speaking, fowl manures (chicken, turkey, duck, goose) have higher values than horse or cow manure. Rabbit is preferred by many gardenres, both for its high nutrient content, and the simplicity of keeping a ready supply on hand. Bat guano and fish meal are favorites of organic gardeners because of their high nitrogen levels.
Whatever source you use, compost it first. Ground bark, fresh manures, tree trimmings, gin trash, or stable shavings can burn tender roots. Apply them well before planting time, or pile up for six months before adding to planted beds. Bagged products usually have been aged already.
There's no sadder sight than a healthy six pack of annuals crammed into native dirt that looks like a jackhammer wouldn't dent it. And no sadder gardener that the one who gives up because plants died that would've made it with just a turn of the soil.