I consider fall lawn care tasks such as fertilizing, core aeration, over-seeding and thatch control to be very important to growing a thick, healthy lawn.
The planting and growing season for cool-season grasses really starts in early fall--not the spring--the warm days and cool nights create ideal conditions for building strong, deep root systems that will help your lawn survive the summer stress from heat and drought.
Fall is the best time to repair lawns, plant new grass and control weeds.
Common cool-season grasses used in lawns include:
This graph illustrates annual root and shoot growth and development. Note the shoot growth and root development that takes place in the fall.
The goal of a healthy lawn maintenance program is to encourage a strong, deep root system to prepare for hot and dry weather.
Fall fertilizer applications are very beneficial. The growing conditions are perfect for improving grass density, increasing carbohydrate storage and root development.Two or three fertilizer applications of 1/2 to 1 pound of nitrogen per 1000 ft2 spaced out 4 to 6 weeks is highly recommended and much more beneficial than heavy spring applications.
Remember the acronym SOD (September, October, December). The 1st fertilizer application should be in early September. Then October when the weather starts to cool and shoot growth is not as heavy. The final application of a "winterizing" fertilizer should be late November or early December while the grass is still green. The supplemental potassium in winterizing fertilizer is very effective in improving winter hardiness.
More fall fertilizer tips:
Fall is the best time to aerate lawns. Lawns growing in heavy clay soils or areas that get a lot of traffic should be core aerated once a year. I recommend aerating every lawn once a year because it is one of the most neglected but most beneficial fall lawn care tasks.
The best time to kill weeds with broadleaf herbicides is when they are actively growing - this is usually in late spring and early fall.
Click here for more information on weed identification and control: How to Kill Weeds.
There are a few natural/organic options available; however, they are non-selective - meaning they kill both grass and weeds - and not as effective as conventional herbicides.
Read more about Organic Weed Control.
Thatch is a build-up of partially decomposed plant material - usually creeping rhizomes and "stemmy" shoots. A little bit of thatch is normal but too much can cause decline of a turf stand. Thatch build-up of more than 1/2 inch needs to be removed by power raking.
The main reason it is best to dethatch in the fall is because power raking is hard on grass plants and often exposes soil to weed invasion. The ideal fall growing conditions also allow the turfgrass stand to recover quickly.
Read more - How and When to Dethatch a Lawn
Fall Hydroseeding - New Lawn
Results After 2 Weeks
Late summer through early fall is the best time to plant new cool-season grasses. The cool nights and warm days are ideal for starting new seed or laying sod.
A perfect time to over-seed thin lawns or repair bare spots
is right after aerating or power raking - these practices create a good
planting bed in established lawns by exposing soil the seeds need to
The Grass Stitcher makes repairing lawns easy. This handy tool preps bare and thin areas for seeding.
Prepare your equipment for winter storage.
How to Winterize a Home Sprinkler System using the "blow out" method.
Improve the reliability of your equipment by preparing your
mowers, leaf blowers, string timmers, chain saws for winter storage.
How to Winterize Your Outdoor Power Equipment.
Question: In the fall I always aerate, over-seed, fertilize and lime. is this right?
Answer: Yes, fall is the best time to aerate, over-seed and fertilize cool season grasses. Lime should only be added if you have had your soil tested and it is recommended by the results. The reason for adding lime is to increase soil pH. The only way to know how much to apply - or if you even need lime - is by having your soil tested.
More Q & A: