Lawns languish in the heat of summer unless showered with water. But don’t worry, the grass is not dead. Come fall when the rains start again, grass greens up quickly, says Alec Kowalewski, turf specialist for Oregon State University’s Extension Service.
While letting your lawn go dormant in summer isn’t bad, lack of irrigation allows pesky weeds to gain a foothold. Regular wear and tear can cause compaction within a lawn, which leads to brown or bare spots.
Now is a good time to whip your lawn back into shape, but starting over usually isn’t necessary.
“Try renovation before putting in a new lawn, because it’s difficult to get a stand of grass established,” Alec says. “If you have something to begin with, go with renovating.”
What you start with can vary from addressing a few brown spots to a desert of weeds to hardpan soil. Assess your lawn’s level of neediness, then proceed with a regular renovation or a no-holds-barred one. Most often, a regular tuneup is all that is needed.
Once your lawn is established, follow Alec’s three steps to a healthy lawn that will outcompete those weeds: water, fertilize and mow properly.
Water 1 inch a week, but don’t do it all at once.
“If you look at the roots, the majority are in the top 1 inch of the soil,” Alec says. “The deeper you go, the fewer roots there are, so watering more than a quarter-inch at a time is a waste. Irrigate more frequently with less amounts when it’s not raining.”
Fertilize four times a year. Apply on Memorial Day, Fourth of July, Labor Day and Thanksgiving.
When mowing, never remove more than one-third of the grass at one time. That means if the lawn is 3 inches long, cut only 1 inch. Cutting more than one-third weakens the lawn, leaving it vulnerable to weeds and diseases.
“Increase the height of the grass as tall as you can stand it,” Alec says. “If you mow it to an inch, you’re decreasing rooting depth and stress tolerance.”
Mow once a week in spring and fall, less often during summer and winter. Consider leaving clippings where they fall. They break down quickly and resupply much-needed nitrogen. The more often you mow, the easier this is to do. Don’t, however, leave clumps of clippings sitting on the lawn.
Steps to Renovate a Lawn
For regular renovation:
- Do a pH test. Either take a sample and send it to a soil lab, or buy a test kit at a nursery. If the pH is below 6.0, add lime.
- Remove weeds by hand or with a broad- spectrum herbicide.
- Aerate lawn with a machine available at rental shops. Pay attention to bare spots or compacted areas. Rake off plugs of soil removed by the aerator.
- Fertilize with a product that has plenty of nitrogen, low or no phosphorus, and a medium level of potassium. Check the fertilizer label and choose something with a high first number (N), low second number (P) and medium third number (K)—such as 20-2-6.
- Overseed at the recommended rate, going a little thicker on bare spots. Use a drop seeder for even distribution.
- Water daily unless it rains.
For major renovation, do the steps above and add the following:
- Mow lawn as short as possible before starting.
- Before aerating, dethatch the lawn with a dethatching machine or power rake to expose as much soil as possible. Run the machine across the lawn twice, in opposite directions. Remove loosened thatch before changing direction.
- After seeding, mulch with a thin layer of sawdust, bark dust or compost. A quarter inch is enough; don’t overdo it or seed will have a tough time germinating.