Sharon Ross, UC Master Gardeners of Placer County
From The Curious Gardener, Fall 2008
Fall is an excellent time to take action to improve the health and beauty of your lawn.
A good place to start is de-thatching. Thatch is a layer of decaying organic matter that occurs between the green matter and the soil. The primary component of thatch is turf- grass stems and roots. It accumulates as these plant parts build up faster than they break down.
Thatch builds up over time to form a thick mat that prevents air, water and nutrients from getting to the roots of the grass. This thick mat also becomes the home to insects and fungal growth.
Ideally, to keep down weeds and reduce evaporation you want to have about one-half inch of thatch. To remove thatch, you need a strong metal bow rake and a strong back. Rake deep into the lawn, using short strokes to pull out the thatch, leaving the desired half- inch. A de-thatching mower is another option.
Soil Compaction
Foot traffic can cause compaction that prevents air and water from getting to the roots. The process of
aeration removes small cores of soil, opening new passages for air and water. There are law-care services with the necessary equipment or you can check out local equipment rentals and do it yourself.
Aeration core removal is more effective than “spiking” holes in the lawn. The frequency needed for a healthy lawn depends on the amount of foot traffic.
Fall Feeding
After aeration and de-thatching, a feeding is recommended. Use a slow-release fertilizer with a NPK (nitrogen, phosphorus, potassium) of 10-5-5. Don’t go overboard on the nitrogen. First, excess nitrogen not taken by your lawn will run off during our first rains. Also, you want to avoid lush fall growth, which is prone to frost and fungal problems.
Other Considerations
Take charge of weeds before they grow. Use a pre-emergent herbicide to keep weed seeds from germinating. As always with any chemical product, follow the manufacturer’s instructions.
If you are planning to start a new lawn or replant an existing lawn, consider downsizing and using alternative plantings.
Lawns consume a great deal of water and chemicals, and require lots of maintenance compared with alternatives such as ground covers, mulches, ornamental grasses and native plants.
References:
“UC Guide to Healthy Lawns,” www.ipm.ucdavis.edu