Sustainability is the new catchword in gardening. When it comes to lawns, it is about proper care and maintenance that allows the lawn to thrive and look good while doing less work and damage to the environment.
Lawns are a permanent crop; once it is growing it is rarely removed.
Unlike other crops, the soil is never worked and amended. In fact the soil stays the same year after year with little thought given to what is below the green surface. Fertilizer is added regularly to keep the grass growing but little, if anything, is done to improve soil structure.
As with any plant, the soil structure is very important. When the soil becomes hard and compacted, the roots have trouble penetrating the soil making it harder for the plants to obtain nutrients.
A few simple steps can rectify the problem. Start by aerating the lawn when the soil is damp but not wet. Use a machine that removes plugs of soil. Just poking holes in the lawn intensifies the problem. Once the plugs are removed the soil will shift slightly, filling in the holes.
As a result the soil will be looser allowing roots to penetrate easily. A better root system increases the plant’s ability to obtain nutrients resulting in a better lawn with less fertilizer.
Plugs that are removed with a roto-rake can be left on the lawn to break down or they can be removed with a sweeper and composted.
Thatch, last year’s dead grass, has been traditionally removed from the lawn in the belief that the grass has trouble growing thatch, resulting in sparse grass. True, lawns usually green up faster if they are raked but unraked lawns are not far behind. Lawns that are over fertilized or not mowed regularly are more likely to have a large build up of thatch that needs to be removed as compared to lawns that are well-maintained. Before de-thatching a lawn, take the time to see how much thatch has built up. A one-half-inch (one- cm) of thatch is ideal.
Lawns are often planted on less than ideal soil which in turn affects the plants growth. Taking the time to top-dress the lawn with compost, well rotted manure or a topsoil rich in humus will improve the soil and ultimately improve the lawn. To top-dress, spread a thin layer (one-half-inch) of organic mater over the top of the existing lawn. Nutrients from this soil will leach down to the grass roots providing easily available nutrients. Grass roots will spread into the new soil. By the end of May, all signs of the top-dressing will have vanished. Repeating the procedure each spring, will build up the soil structure; improving the lawn’s health.
If there are problem areas where grass does not grow, spread grass seed over the top dressing. Most pre-mixed grass seed contains a large mixture of bluegrass seed and will blend into existing lawns. For the hard-to-grow areas — wet, shady or hot and dry — purchase seed mixtures designed for those specific conditions. These mixes are not found in the average big box or hardware store. Independent garden centres should have a number of specialty mixes on hand but for the best variety look to seed companies that specialize in land reclamation or pasture seed. They will be able to put together a mixture of seeds that will suit your needs.
Try aerating and top-dressing the lawn this year. It might appear to be extra work this spring but it should cut down on the need to water and fertilize later in the year.
Linda Tomlinson is a horticulturalist and educator living in Rocky Mountain House. You can contact her at firstname.lastname@example.org