To Seed or Not to Seed: Fall Lawn Care

By Allyn Hane - "The Lawn Care Nut"
September 14, 2019

We are well into September now and that means you folks with cool-season lawns: Kentucky Bluegrass, perennial rye and turf-type tall fescue will be thinking about throwing down some grass seed in thin areas. Others of you may be considering full-on aeration with overseeding across your entire lawn.

But what if you didn’t seed this year?

What if you took on a different strategy; one that encourages your lawn to pack on the root mass this fall while you also protect it from fall germinating annual broadleaf and grassy weeds? I bet you could see some good results that way for sure.

Dormant Lawn with Bittercress

Photo: Bittercress in a dormant lawn in spring

For a good portion of the country, September and early October’s mild temperatures and added moisture are going to trigger your cool-season turf types to put in roots in preparation for the winter ahead. The days are getting shorter but these months still provide quite a bit of daily sun as compared to the shortest days later in winter. Let’s take advantage of that sunlight while we still have it!

This is the time to do 2 things: Push and Protect.


If your lawn has thinned out in summer either from the excessive heat and lack of water or from disease or insects, now is the time to give it a boost and you do that in two ways: frequent mowing and frequent, spoon-feeding of nutrients.

I’ve mentioned before, the more you mow, the healthier your lawn will grow. Frequent mowing stimulates grass plants to fatten up and push more roots. Since it’s fall and your turf is doing this naturally anyway, frequent mowing (every 3-4 days if you can) will add an additional nudge in the right direction. Push it!

Additionally, all this growth is going to require nutrient support in the soil so every 4 weeks during fall, spoon-feed in light doses of Milorganite. An easy 10lbs/1000 will keep things moving nicely. You can feed with Milo all the way up until the lawn pretty much stops growing for the season and call that final application a “winterizer.” The idea is to push it, and pack on the pounds.


Now while we are working to push our turf,  let’s also consider protecting it from nasty invaders like chickweed, henbit, hairy bittercress and poa annua (annual bluegrass). These are fall germinating annuals that will live over winter and rage in your lawn next spring. Best to keep them out.

Henbit Germinating in Fall

Photo: Henbit a fall germinating weed

This is done by applying pre-emergent herbicides in fall time to prevent them. Two of the active ingredients you may find online or in stores are dithiopyr and prodiamine. These are both labeled to prevent these pesky weeds listed here and can also be used the following spring to prevent crabgrass, a spring germinating invader.

Preventing these weeds now can actually reduce your future herbicide usage as well. Much easier to prevent weeds before they appear than to try and spray them out later in spring when rains and warm temps are pushing them to expand and drop seeds.

Keep in mind, this strategy is for you if you are not going to apply grass seed to the lawn.

We are at that time where you can make great strides in the lawn again. I know several of you have struggled to keep your gains through this brutal summer. Fall is the time to recover, push and also protect.