The First Key to Success with Lawns: Good Soil
When I hear people complain that their lawn is full of weeds, turns yellow, suffers from dead patches, is infested with insects and diseases, etc., I know the reason right away. Someone decided, perhaps a long time ago, to save cash by installing sod without taking a crucial step: putting down a good layer of quality top soil first.
I’m not necessarily blaming the current owner. You may have bought your home second-hand. And even if it is a new dwelling, it may well have been the builder who installed the turf and, as is so often the case, decided to cut corners by laying sod directly on crappy landfill.
And what a mess a lawn becomes when it planted on poor soil! Of all the things you grow, only the vegetables depend more on good soil than a lawn. Yet, at first, the problem is not too obvious. Sod covers a lot of defects and at first the lawn may well seem fine, even it was placed directly on clay, sand or construction waste. But in most climates, the only sod grass sold in rolls is Kentucky bluegrass (Poa pratensis) and it is the most demanding of all the lawn grasses. This grass will often live on its reserves for a year or two, actually looking quite nice and giving the impression that the installation was successful, but it begins to fall apart over time. And when it weakens, weeds, insects and diseases move right in.
You simply cannot grow a good lawn on poor quality soil. It takes at least a 6-inch (15 cm) layer of good soil (8 inches/20 cm is even better!). Ideally this will be a soil mix especially designed for lawns, structurally more stable than, say, a blend for vegetable gardens, as it has to put up with foot traffic. It should be free of weeds and contain no “black earth” (black earth, as sold in garden centers, is not actually earth at all, but a peat waste product: it’s not something you’ll ever want to use in a garden). Also make sure that the top soil you buy is free of weeds.
With good soil at its base, you’ll have no trouble keeping your lawn in excellent condition!