Fertilizing your lawn properly is the most important step you can take during Fall lawn care season. Fall is the best time of year to fertilize your lawn. The cooler temperatures and increased rainfall help the nutrients in the fertilizer to be absorbed more deeply into the soil, where they can be stored for use by the grass roots during the winter and early spring.
Fertilizing in the fall also helps to strengthen the grass roots and make them more resistant to winter damage and stress. This can lead to a healthier, greener lawn in the spring and summer.
What Type Of Fertilizer To Use In The Fall
There are many types of fertilizers available, some marketed to sell in the Fall. Regardless of the fertilizer name and what it claims to do, you should get a fertilizer that is high in Nitrogen. Nitrogen is what makes the grass green and promotes growth.
A good rule of thumb is to choose a fertilizer with an N-P-K ratio of 20-10-10 or 24-8-12. This means that the fertilizer contains 20% nitrogen, 10% phosphorus, and 10% potassium. If you really want to push your lawn to produce a dark green color though, do what I do and apply a fast release fertilizer.
I apply straight Urea, 46-0-0. This is essentially all Nitrogen, and because there’s a lot of it, you need to be careful to not over apply. Know your lawn dimensions to determine how much to put down.
Also, there is much less risk of burning your lawn with this fertilizer as the temperatures are cooler. Urea fertilizer should only be applied in the Fall. You will burn your lawn if you apply it during the warmer months. Urea isn’t sold at big box stores but you can find it at some local feed stores.
When To Fertilize Your Lawn
In the northeast, the best time to fertilize your lawn in the fall is between 6 and 8 weeks before the first frost. This will give the grass roots enough time to absorb the nutrients and store them for use in the winter and early spring. This means that you can begin to fertilize in the beginning of September. Make sure that you are prepared to water the lawn after applying fertilizer, especially if you are applying Urea.
How To Fertilize Your Lawn In The Fall
The idea with using Urea is to spoon-feed the lawn giving it small amounts of fertilizer but more often. And because it’s quick release, the lawn gets those nutrients much faster, however, it also means that the fertilizer doesn’t last as long. This is why I feed the lawn biweekly in the Fall, with just enough Urea fertilizer so that the lawn gets .5 lbs of Nitrogen each time. I will keep doing this until the first frost which usually results in a total of about 2 lbs of Nitrogen. If overseeding, wait until the grass has been mowed a couple of times before beginning this biweekly fertilization schedule.
What To Do After The First Frost Date
After the first frost, the lawn will begin to slow its growth. This is a sign to also stop fertilizing it. You don’t want to push growth when the plant is naturally slowing down for the winter months. There is however one last time that you can fertilize your lawn to give it a boost for a quick green up the following Spring. This is what’s referred to as winterizing your lawn. If you choose to do this, it has to be timed correctly.
When you notice the grass has stopped growing but the ground is not yet frozen, this is the right time to winterize your lawn. It’s about a 3 week window and it usually falls around the 3rd week of November here in the northeast, when the soil temperature is between 45-50 °F. DO NOT apply if the ground is already frozen!
At this time, I will apply Urea at a rate of 1 lb. per 1,000 sqft. This will give the lawn about 1 lb. of Nitrogen. It does not need to be watered in and can wait until it rains or snows. It won’t push top growth because the soil temperatures are in the 40’s which is too cold for the grass to grow. Instead, the grass will store the nitrogen over the winter for a boost next Spring.
Tips For Fall Lawn Care
- Water your lawn deeply twice a week or more often if necessary (about 1 inch or more per week including rain).
- Apply enough fertilizer to yield about 1 lb (per 1000 sqft) of nitrogen per month (September – November).
- Mow your lawn regularly, but don’t mow it too short. The last mowing of the season should be 1 or 2 notches shorter than the previous mowings.
- Remove any leaves or debris from your lawn. This will help to prevent pests and diseases from overwintering in your lawn. Leaves can be mulched, benefiting the soil.
- An optional step is to apply a pre-emergent herbicide in the fall to prevent weeds from germinating in the spring.
By following these tips, you can help to ensure that your lawn comes out of the winter looking its best.
