I have a confession to make: I like weeding. In the late afternoon cool of a summer day, I'll grab my iPod and saunter out to the garden with my favorite crescent-shaped hoe. Slicing with the hoe along the edge of a bed, I beat back the quackgrass, pausing to bend over and pull out the long, stringy roots. Sometimes I don't even take a hoe, just kneel along a row of carrots and work with my fingers, thinning the carrots and scuffling the small weeds hiding there.
It's slow work and quiet, and it gets me down close to the ground where I can see and feel what's going on around and under my plants. There are always bits of corn cobs or plant stalks in the dirt from compost that has been added; big fat ground beetles trundling around; earthworms galore. The crumbly consistency of soil in the long-established garden beds is very different from the washed out, grainy soil along the edges that I cut into with my hoe. The same weeds that I whisk out with my fingers from under the spreading leaves of a bean plant might as well be cased in cement when I attempt to pry them out of unworked ground.
What makes the garden beds so plush, and the grassy paths so tough? The difference is in structural characteristics of the soil. Garden soil is well structured - it clumps together loosely and contains pores of many sizes that allow air and water to permeate. Unimproved soil has little structure, falling apart easily into individual grains if it has a lot of sand, sticking together in a hard mass if it's clayey. Garden plants grow poorly in these kinds of soils, allowing scrappy weeds with their sharp roots to take over.
How soils develop good structure is complicated, and a little mysterious. The underlying substrate is a factor. Here in the Adirondacks the soils are naturally thin and nutrient poor, with little natural structure. Chemical weathering, like the freeze/thaw cycles of late winter or prolonged drying in the summer breaks down structure. The interconnected world of bacteria, fungus and microbes play a part in creating clumps that hold together. And that darling of the garden, the earthworm, works magic in the dirt, tunneling through bits of hard minerals and leaving behind a wake of enriched soil.
Fortunately, almost every soil can be coaxed to improve structure with a few simple steps. First, stay out of the beds! The light porous texture of good soil is compressed by repeatedly walking up and down the rows. Make sure your beds are narrow enough that you can reach into the middle of them, maintain good garden paths and keep your feet in them.
Second, reduce or eliminate tilling. Rototillers tear up the aggregate clumps and break down organic matter, making the soil full of smaller, dusty particles. Try raking with a steel rake or turning gently with a digging fork. If you need to till for weed control, do it less frequently.
Third and most important, add organic matter whenever you can. As well as containing plant nutrients, decaying organic matter feeds the microbes and earthworms that do the work of building the soil. There are many ways to add organic matter. You can dig in compost when you plant, mulch with hay or straw around transplants, top dress with well-rottedmanure, or grow a cover crop over the winter. Feed your soil and it will feed you.