Fall lawn care involves leaving it somewhat long for winter

Melanie Mathieson
Gardening Guru

Late fall is a fairly quiet time for lawn care. You have probably stopped mowing your lawn in September, because you want to mow and then allow your grass to grow to about 3”-4” before the ground freezes. By keeping your lawn longer before it dies back for the winter allows for a layer of insulation to form over the roots. This layer of insulation is very beneficial for protecting the roots not just during the cold winter months but especially next spring when the snow has melted but the ground thaws and freezes as the early spring temperatures fluctuate. Make sure that you rake all of the fallen leaves off of your lawn in the fall. Fallen leaves can become matted and harbour moulds and disease that can affect your lawn. A clean lawn allows for the grass to continue to store carbohydrates (food) right up until the frost forces the grass into dormancy and after our hot dry summer your lawn needs the extra help. Making sure that the ground is fully saturated before freeze-up will also ensure your lawn remains healthy over the winter.
Fall is a great time for some extra lawn maintenance. Consider aerating to help the soil under your lawn. Even a thorough raking of leaves can provide your lawn with some surface aeration. Or you can rent an aerating machine from your local rental centre that punctures the surface of the soil and pulls plugs out to allow for better drainage of moisture and nutrients and prevents compaction of your lawn and the root zone of the lawn.
It is currently too late for seeding a lawn at this time of year. Even if the seeds germinate in the cooler weather the grass seedlings most likely will not harden off for winter and die once they are nipped with frost. Some people will lay sod this time of year, as the literature states that you can lay sod right up until the ground freezes but I like to recommend laying the sod while the temperature is still warm enough for the roots to continue growing so that the sod adheres to the ground before winter. Nonetheless if you have planted sod this time of year make sure you adequately water it right up until the ground freezes.
Many people in this region do not realize the benefits of fall fertilization of your lawn. Fall fertilizing is best done as the growth rate of the grass is starting to taper off usually in late September if the weather isn’t too warm. Fall fertilizing can take place right into late October. A very important tip is that fall lawn fertilizer is a special blend of nutrients. Never use the leftover fertilizer that you applied in the spring. A spring fertilizer is high in Nitrogen (N). Fall fertilizer contains high amounts of Potassium (K) which is vital for root development. This means that the last number on the bag will be the highest. In the fall, grass roots remain active until the soil starts to freeze as a result, the lawn continues to benefit from the nutrients in the fertilizer, especially from the Potassium, well into the fall. If you applied a fertilizer meant for spring the nitrogen would promote leaf (blade) growth and cause your grass to grow fast in furious in the warm fall weather, once frost hits the grass it will kill it because of its tender growth. So as I always recommend, purchase a high quality fertilizer (approximately 400m2 of coverage per bag). You can also purchase a ‘weed-n-feed’ mixture at this time of year as well. Apply the fertilizer exactly according to the directions and at the recommended coverage. You may not see the benefits of this fertilizer in the remainder of this growing season but you will sure notice a difference come spring. The fertilizer will have strengthened the roots allowing for more transportation of nutrients making for a stronger and greener grass earlier in the spring. If you use a fertilizer/weed control formula you will notice a reduction in the weeds in your lawn in the early spring. When the neighbours are sporting weeds in their lawn yours will be virtually weed free.
A few simple lawn care tips and chores in the fall will help to ensure that your lawn stays healthy under the snow and gets a jump start in the spring.