Caring homeowners always seem anxious to fertilize their lawns, perhaps hoping that will help turf recover or overcome some seasonal struggles. Appropriate fertility is just as important to the lawn as things like proper mowing height, consistent watering and weed prevention. They all work together!

But fertilizing at the wrong time may do more harm than good! Plants, and grass included, always make best use of food and nutrients when they’re actively growing. If warm season lawns are still dormant, their roots aren’t going to uptake that fertilizer quite yet, but the existing weeds sure will. Considering a cool season lawn like fescue, one last application of fertilizer could be applied between March and early April.

Another thing that could get homeowners a bit caught up is choosing between preemergence herbicides (ie: weed preventers) and seeding. I recently received this question from a listener: “I planted fescue in the fall, though there are some shallow areas I’d like to re-seed in spring. Lawn calendars suggest March is best for re-seeding, fertilizing AND pre-emergence. How do I prioritize?”

This is a great question. There isn’t really a safe window, within the season, to apply preemergence AND seed, because the herbicide will counteract grass seeds trying to grow. In fact, it will inhibit them.

And which combination of the tasks to do really depends on how many weeds are present. The healthier and more lush the lawn, the better chance of choking out weeds. If there aren’t typically a lot of summer weeds, I’d just stick with reseeding. Fertilize fescue once the new blades are coming up. But, if the fescue looks unhealthy over the summer and there are too many weeds, put down a preemergence by mid-March and forgo any seeding. Wait until fall to aerate and seed in that case.

Here are tips for feeding your lawn from NG Turf.

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