Here are six critical organic lawn-care strategies for doing exactly that, courtesy of Paul J. Tukey, author of The Organic Lawn Care Manual (Storey Publishing, 2007).
#1: Mow lower
With the days growing cooler, it’s safe to lower your mower blade from about 3 or more inches to 2½ inches. While a key organic lawn-care tactic is to keep the blade high so the grass will produce more nutrients, that's not as important in the winter, when grass is dormant. Drop the blade to 2 inches for your final mowing, which is usually in early November for most parts of the country. “If you leave the grass too high heading into winter,” says Tukey, “you may be creating a nice haven for field mice, which can damage the lawn.”
#2: Fill in any thin spots
Planting new grass seed to thicken thin areas is a fall lawn-care chore, says Tukey. In the spring, the soil tends to heat up too fast, drying out the roots before they get a chance to develop. To ensure excellent seed-to-soil contact, be sure to scratch the soil with a bamboo rake or mechanical machine known as a dethatcher before you scatter the seed. Cover with a light layer of compost or healthy soil to increase the germination rate. Then water the area frequently to keep the new seed moist while it germinates.
Just because your lawn has stopped growing doesn’t mean you should stop feeding it. “The goal in autumn isn’t to push out loads of growth above the soil,” says Tukey, “it’s to establish healthy roots that can make it through winter and allow the grass to green-up faster in the spring." A healthy root system is key for organic lawn care, since it makes it easier for the grass to resist pests and weeds. "An early-autumn fertilizer should have potassium, phosphorus, and calcium in abundance, with less emphasis on nitrogen.” Alfalfa-based fertilizers are perfect this time of year, he adds. Plus, late in the fall, an application of corn gluten meal can work well.
#4: Test your soil
Grass grows best in soil with a neutral pH (around 6.5 or 7). If your soil has a pH under 6.5, it’s too acidic (a common problem in highly populated areas with acidic rainfall), and you’ll need to add ground limestone (a perfect autumn job) to bring it back into balance. If the pH is over 7.5, your soil is too alkaline and in need of soil sulfur. To find out what your lawn needs, you need to find out its pH first. You can purchase a soil test kit from a local nursery or extension office, and follow the instructions on the package. Or, as Tukey suggests, you can send soil samples to the Soil Foodweb New York Laboratory (www.soilfoodwebnewyork.com) for more expensive but more comprehensive testing.
# 5: Pull the weeds
Since common weeds like crabgrass, plantain, and chickweed go to seed in the fall, lawn care during this time of the year should include some serious weeding. “If you look closely at any of these plants, you’ll see the seeds beginning to form at the tops of the plants right about now,” says Tukey. “If those seeds dry out and hit the ground, you’ll have even more of the weeds next year—which means you’ve got to prevent them from doing so.” Do some weeding now to spare the temptation to kill weeds with unhealthy synthetic chemicals in the spring. You can either pull them (they’re large and easy to grab now) or mow them with a bagging attachment, so the seeds don’t have a chance to hit the soil. Or, you can spray them with a vinegar solution, a classic weapon in the organic lawn-care arsenal. “Look for at least 10 percent vinegar in the solution,” says Tukey. You can mix your own vinegar and water, or buy a commercial product. Tukey suggests trying products by Perfectly Natural.
#6: Rake regularly
Raking up leaves isn't just cosmetic; it's an important piece of fall lawn care. Not only will your lawn look neater, post raking, but keeping excess leaves off the lawn prevents dead patches the following spring, says Tukey. A heavy layer of autumn leaves can mat the lawn and smother it. Organic lawn-care tip: Shred those raked-up leaves and toss them in your compost pile, or use them as mulch in your spring garden.