If you seed your lawn in early Fall, the seedlings will have 9 to 10 months to develop deeper root systems before they have to experience their first Summer of hot and dry weather. Compare this to 1 or 2 months for a Spring seeding, and the chances of an early Fall seeding surviving to maturity are significantly greater. On top of that, you can still apply your pre-emergent in Spring and keep out the crabgrass and other weeds throughout the season.
As part of a normal lawn care program, pre-emergent is usually applied in the Spring to help prevent crabgrass and many other types of weeds. That is the good part about pre-emergent. The bad part about pre-emergent is, it also prevents good grass seed from germinating. If you put seed down all over your yard and then a pre-emergent is applied over the top of it, chances are, the seed will not germinate, or will experience a very low germination rate.
As with any rule or recommendation, there are always exceptions. For example, you may want to seed in the Spring if you had extensive drought or grub damage during the previous summer or fall. Pre-emergent works best on a thick stand of turf, but it does not work well in areas where there is exposed soil and not much grass. In cases like this, you have to compare the pros and cons. If you have a lot of bare spots, and you wait until Fall to seed, you may end up with a lot more weeds in those bare spots throughout the season. If you skip the pre-emergent and seed the bare areas in the Spring, you will prevent a lot of weeds in those bare areas, but you might experience some crabgrass or other weeds throughout the lawn.
One common question I am asked every Spring is, “Should I seed my lawn in Spring or Fall?” Many homeowners are eager to start thickening up their lawn as soon as they get a glimpse of good weather in early Spring. We sometimes still have a late March snow on the ground when the calls start coming in. My answer to their question is the ever-popular “It depends.” After explaining the pros and cons to many homeowners over the years, I’ve put my recommendation in writing on this page.
Repair prior year damage or bare spots in Spring (month of April)
Seeding your lawn in Spring
Grass plants depend on deep, healthy roots, and a tall, thick stand of grass blades to help it survive the stresses of Summer. Deep roots allow the grass to reach moisture that lies beyond the dried out top layer of soil. A tall and thick stand of grass blades help to shade the soil and prevent weeds from competing with the lawn. When you seed in the Spring, the new grass plants may come up very nicely after a few weeks, but under the soil, the roots will not yet be deep enough to survive Summer without a significant amount of irrigation from a sprinkler system. Unless you keep the seedlings watered all summer long and into early Fall, the chances of their survival is slim to none.
Over-seed the entire lawn in Early Fall (late August through early September)
Warm-season grasses often go dormant and turn brown during winter, leading many southern lawn owners to overseed lawns with a cool-season grass that provides temporary green color through the winter months. Overseeding should take place at least 45 days before your average first fall frost, so new seeds can establish before winter. 2 Fertilize newly overseeded fall lawns with a starter fertilizer such as Pennington UltraGreen Starter Fertilizer 22-23-4, which supports robust root growth and greening of the cool-season grass. Avoid using weed & feed products on newly overseeded lawns, as they may prevent germination of the new grass seed. Consult your local Cooperative Extension Service for current information on limits for lawn fertilizers in your region.
Pennington and Myco Advantage are registered trademarks of Pennington Seed, Inc. Amdro and UltraGreen are registered trademarks of Central Garden & Pet Company.
Feeding Cool-Season Lawn Grasses
Fall’s arrival brings changes in day length, temperature and precipitation, along with important changes in your lawn. Some lawn grasses and weeds begin to slow down and prepare for winter dormancy, but others kick into high gear. Feeding your fall lawn provides helpful nutrients to fight weeds and strengthen lawn grasses for the winter ahead. However, what and when to feed and how to manage weeds depends on your climate and the type of grass you grow.
Warm-season grasses, such as Bermudagrass, bahiagrass, centipede grass and zoysia grass, thrive in southern regions and peak in growth during warm summer months. As fall approaches, their growth slows and dormancy sets in with the season’s first killing frost.
Fertilizing Warm-Season Grasses
In established fall lawns, weed & feed products help prevent cool-season weed seeds from germinating and emerging. In dormant southern lawns, emerged cool-season weeds stand out bright green against brown lawn grasses, which makes spot treatment easy. Effective post-emergent weed treatments, such as IMAGE All-in-One Killer, offers broad-spectrum fall control for difficult sedges, crabgrass and broadleaf weeds. IMAGE Kills Nutsedge, available in concentrate and ready-to-spray formulas, controls winter weeds in warm-season lawns, including Poa annua, also known as annual bluegrass, a troublesome annual weed common in Bermudagrass lawns.
Warm-season grasses, like Bermuda grass and St. Augustine grass, grow rapidly in warm weather. Generally, you will feed warm-season grasses from late spring to early fall. If you fertilize too late in fall, the grass is likely to be less hardy as it enters slow growth during colder weather and is more susceptible to winter injury.
The second number stands for phosphorus, which helps new lawns get established and also helps plants and shrubs root growth. Because of the concern for excess phosphorus in lakes and rivers from fertilizer, many states now restrict or reduce phosphorus content in fertilizers.
Fall is also a good time to kill weeds in your lawn. You may need to simply feed your lawn with fertilizer or apply a fall weed and feed product to kill weeds also. Lowes has two products to help your lawn as the fall season begins; Scotts TurfBuilder Winterguard Fall and Winter Fertilizer and Sta-Green Winterizer Fertilizer. Both are available in regular or weed and feed versions.
Lowe’s exclusive brand of non-phosphorus Sta Green Winterizer has a ratio of 22-0-14.
What Kind and When to Apply Fertilizer in the Fall:
Cool-season grasses, such as bluegrass, perennial ryegrass and tall fescue, grow most vigorously in the spring. They also have a growth spurt during the cooler months of fall but become dormant in winter. Also be aware that some cool season grasses are grown in southern climates. In some areas, such as the deep South and southern California, cool-season grasses can also be grown throughout winter.
So what kind of fertilizer should you apply in the fall and when do you apply it? Follow the same guidelines as you do in the spring. If you have weeds, use a fall weed and feed product. If weeds are not a problem, use a fall fertilizer only.
Remember that the most important nutrient for a fall fertilizer or fall weed and feed is nitrogen. Make sure to use a high-nitrogen fertilizer. Scotts Turf Builder WinterGuard With Plus 2 Weed Control has a ratio o 26-2-12.
Weed and Feed In September and October
You can help your lawn continue to look its best when you apply a fertilizer to your lawn in September or October. Many fall or winterizing fertilizers are higher in potassium than regular fertilizer or lawn food. Potassium is the nutrient that makes grass more winter hardy.
Fall is a very important time to feed cool-season grasses, keeping them growing longer into cool weather and providing the nutrients needed for quick green-up next spring. Fall fertilizer application should be done while the grass is still green and about 3 weeks before the ground is expected to freeze.