Summer fun may be a memory but that doesn’t mean we forget about our lawn. Fall is the most important time of the year to fertilize, aerate, over-seed and control broadleaf weeds. As a matter of fact, if you were only going to fertilizer your lawn once per year, Labor Day would be the best time of year for that application. For higher quality lawns, we recommend a September fertilization followed by a late fall fertilization in early November. Fall nitrogen promotes root development, enhances storage of energy reserves, and extends color retention in cool-season lawns. Most of the benefits from late fall nitrogen will be seen next spring and summer with earlier green-up, improved turf density, and improved tolerance to spring diseases.
Using an aerator removes small cores of compacted soil and dirt from the soil. The holes, about 2-3 inches deep and usually no more than 4 inches apart, allow the soil to breathe and help the ground act as a sponge that absorbs everything it is given. Aeration also breaks up thatch to prevent soil compaction and hardening, making it easier for fertilizer to reach the grass seed at its roots. Core aeration is a particularly important part of the fall-scheduled maintenance.
How aeration helps turf with compacted soil grow healthier, deeper roots.
Although there are many different fertilizer sources both organic and synthetic, which every way you go, these products work very well in the fall. Your September application should contain a higher nitrogen percentage and have a slow release. This application will help the lawn recover from summer stress quickly, improve color and overall appearance. The timing of the September application is to apply once the daily temperatures have cooled from the summer heat. The target application rate for this fertilization should be 1 lb. of nitrogen per 1000 square feet.
Your late-fall or November application timing should be near or shortly after the last mowing of the year, while lawn is still green. Typically, there may be a month or more between your last mowing and the time the grass turns brown or goes under snow cover. Generally, the first few weeks of November are when to apply. Purdue University research suggests that the nitrogen must be taken-up by the plant before winter to be most effective. Therefore, a quick-release (or soluble nitrogen source) such as urea, ammonium nitrate, calcium nitrate, or ammonium sulfate is most effective. The target application rate for this November fertilization should be .5 to 1 lb. of nitrogen per 1000 square feet.
In the fall, weeds prepare for winter by pulling nutrients and starches from their leaves into their roots.
If you are looking to seed bare spots or thin areas, September is the perfect time to do this. Cooler night temperatures, along with lower humidity and warm days, keep the soil at an ideally warm temperature for grass seed germination. Be cautious however, because if you wait too long into the fall to plant grass seed, an early winter could cause the young grass to die. That is why we like September for this. It gives you plenty of time for your young grass to mature before the cold hits.
September is also the best time to apply herbicides to control dandelions and other broadleaf weeds that will pop-up in the spring. In the fall, weeds prepare for winter by pulling nutrients and starches from their leaves into their roots. By doing this they will also draw herbicides into their root systems thus killing the weed more efficiently. This will allow actively growing grass to fill in the bare spots created after the weeds die.
Following these basic steps now will greatly help to diminish or even prevent any problems and are key to keeping your turf looking great.
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