We don’t live in Florida, so cooler temperatures aren’t far away. That means you’ll want to get your fall yard projects done before winter sets in. With Washington, D.C,’s average low temperatures in the 20s in winter, the cold can do a number on your Washington, D.C., area home and yard … unless you prepare for the following spring growing season.
A Checklist of Chores
- One final mowing. Grass blades should be left a couple of inches long.
- Rake leaves and remove any thatch and dead grass.
- Test the soil pH before adding any chemicals or fertilizers.
- Fertilize with synthetic or organic products.
- Apply pre-emergent herbicide for weed control.
- Reseed brown and bare spots.
- Water and aerate.
Your lawn may contain one or more types of cool-season grasses such as Kentucky bluegrass, perennial ryegrass, or fescues. But Bermuda, a warm-season grass, is the most popular type for lawns in the Washington D.C. area and can handle the heat and humidity of summer and the cold winters. In fact, you can overseed with Bermuda grass for a thick-growing lawn come springtime.
Your lawn needs one last sharp cut before winter sets in. Lower the mower blades if necessary — the grass should be 2 inches high. Do not remove grass clippings: They will act as a natural fertilizer. This also gives you a chance to mulch some of the leaves, which also serves as a fertilizer. Add pre-emergent herbicide to help control weeds that pop up as soon as warmer temperatures arrive.
For more information about mowing your DC lawn, check out this guide by Wikilawn.
Deciduous trees mean that leaf-raking is unavoidable While a few leaves on the ground won’t hurt the lawn — in fact, they’ll help it — leaving a heavy layer of leaves will.
If you have a lot of trees on your property, rake or blow every couple of days so you won’t have to do it all at once. Wet leaves stick together and create vegetative mats that suffocate the grass, breed fungi, and attract insects.
Soil Testing and Fertilization
To determine pH balance, always test the soil in the turf before adding fertilizer. A soil’s pH is a measurement of hydrogen ion concentration — the more ions present, the more acidic the soil is. The pH scale is 1 to 14; levels below 7.0 are acidic. Above 7.0 is alkaline.
Washington D.C., soils are very diverse, but many tend to be overly acidic. A pH reading of 5.5 or below may be great for growing rhododendrons, azaleas, and camellia plants but it’s nearly toxic for turfgrass.
The pH for growing healthy sod in D.C. should be between 6.2 and 6.8. Adding the appropriate amount of lime to the soil every six weeks raises the pH about a half-point every few months.
When it comes to fertilizing, you must choose a product best suited for the lawn’s pH balance. Natural products such as bone matter, plant-based, or compost are preferable because they’re better for the environment. But you can also use chemical fertilizers with the right amounts of NPK; nitrogen, phosphorus, and potassium.
When it comes to weeds, you cannot eliminate them from your lawn, garden, or flower beds. But in autumn, you can treat the lawn to help prevent weeds from appearing in spring. Weeds are the result of poor mowing practices, overwatering, inappropriate fertilizing, compacted soil, and bare spots.
Seeds germinate in later summer throughout the fall and then sprout up in early spring. Apply herbicide in the fall and spring. Treating the grass in fall keeps chickweed, henbit, and deadnettle at bay. If you treat for weeds in fall, you will still see those pesky and abundant dandelions in spring — but not nearly as many.
The most important thing to know about overseeding a lawn in the fall is timing. Overseeding too late in the season means plants will germinate and then not survive in colder temperatures of winter. That goes for fertilizing as well because the grass roots cannot absorb nutrients.
Spring is generally the best time for reseeding Bermuda grass, but if you do it in autumn, do NOT plant anything later than 90 days before the first expected frost. Mid-August is your best bet for healthy growth the following spring.
Water and Aeration
It may seem silly to water when it’s so cold outside, but turfgrass needs about an inch of water per week during the fall and winter. Snow and rainfall help with this. Washington, D.C., receives 2 to 3 inches per month during December, January, and February.
Keep an eye on the weather forecast and for any signs of unexpected winter drought. Core aeration — the process of punching holes in and removing cores from the sod — helps grass roots absorb moisture, oxygen, and nutrients.
If your yard is small, you can aerate by hand, but it’s less time consuming and labor-intensive to buy (or rent) an aerator. Better yet, hire a pro to handle all the dirty work, especially if your lawn is larger than an acre.
If you want that sweet green carpet of thick, green grass, prepping the lawn for its winter chill will mean less work in the spring. Having a checklist will help you organize your fall home maintenance projects.
Guest poster and lawn expert Bill Campbell is a landscaper and gardener who’s been mowing lawns since he was 14. He prides himself on being eco-friendly and maintains a green lawn without using chemicals.