Your September Yard Checklist: What to Get Done Around Metro Atlanta This Month

If you’ve lived in Georgia through a few Septembers, you know the drill. The calendar says fall, but the thermometer didn’t get the memo. Here in Marietta and across Metro Atlanta, we’re usually still sweating through 85-degree afternoons well into the month — but don’t let that fool you into thinking your yard can wait. September is quietly one of the most important months on the landscaping calendar here in North Georgia, and if you skip it, you’ll feel it in your lawn and garden come spring.

We talk to customers every day at our Marietta yard who are surprised to learn just how much of the “real work” happens now, while everyone else is still thinking about pumpkin spice. So grab a coffee (or a hose), and let’s walk through what actually needs your attention this month.

1. It’s Prime Time to Overseed Your Fescue Lawn

If you’ve got a tall fescue lawn — which describes a huge chunk of yards in Cobb, Cherokee, and North Fulton counties — September is genuinely the single best window of the entire year to overseed. Fescue is a cool-season grass, and it germinates best when soil temperatures are cooling down but the air is still warm enough to establish strong roots before winter.

A few tips for getting this right:

• Mow shorter than usual right before you seed, and rake out thatch so seed makes good contact with soil.
• Top-dress with a thin layer of quality topsoil or compost to help seed-to-soil contact and retain moisture.
• Water lightly but consistently — think “keep it damp,” not “drown it” — for the first two to three weeks.

If your lawn has thin, bare, or scalped patches from our brutal Georgia summer, this is your chance to fix them before winter dormancy sets in.

Note for Bermuda and zoysia lawns: these warm-season grasses are heading toward dormancy, not growth. Skip the overseeding (unless you’re doing a temporary ryegrass overseed purely for winter color) and instead start tapering off nitrogen fertilizer to help the grass harden off properly for winter.

2. Refresh Mulch Before Leaf Season Hits

Mulch does a lot of quiet work — regulating soil temperature, holding in moisture, and suppressing weeds — and by late summer, most beds around Metro Atlanta are looking pretty tired and sun-bleached. Early-to-mid September is a great time to lay down a fresh two-to-three-inch layer of mulch before leaves start dropping and complicating the job.

Fresh mulch now also helps insulate the root zones of shrubs, perennials, and any new fall plantings against the temperature swings that are coming. Whether you’re a hardwood mulch person, a pine straw loyalist (very popular in these parts), or you’re experimenting with something new, now’s the time to stock up.

3. Start Fall Planting — Trees, Shrubs, and Perennials Love This Window

Here’s something a lot of homeowners don’t realize: fall, not spring, is actually the ideal planting season in the Southeast. Soil is still warm from summer, which encourages root development, while cooler air temperatures mean far less stress on the plant compared to a July planting. September through November gives trees, shrubs, and perennials a full season to settle in before they’re asked to push out new growth next spring.

Good candidates to get in the ground this month include:

• Native trees and shrubs suited to Georgia clay soil
• Perennials that’ll bulk up and be ready to bloom next year
• Cool-season color like pansies, violas, and ornamental cabbage toward the end of the month

If you’re planting in typical red Georgia clay, don’t skip amending your soil — a good topsoil and compost blend makes a real difference in how well roots establish.

4. Divide and Transplant Perennials

If your Daylilies, Hosta’s, or ornamental grasses have gotten overgrown and less floriferous, September is a great time to dig them up, divide them, and either replant or share with a neighbor. Cooler weather means less transplant shock, and the plants have time to root in before dormancy.

5. Get Ahead of Fall Cleanup Before Leaves Really Start Falling

It’s easy to think leaf season is an October or November problem, but a little prep now saves a lot of headache later. Late September is a good time to:

• Clear out summer annuals that are done producing
• Cut back perennials that have finished blooming
• Do a first pass of light pruning on shrubs (save heavy pruning for late winter dormancy)
• Clean out gutters and drainage areas before the leaf drop really ramps up

6. Check Your Irrigation System Before You Shut It Down

As watering needs drop off with cooler temps, take the opportunity to walk your yard and check for broken sprinkler heads, leaks, or coverage issues you may have been ignoring all summer. It’s much easier to spot problems and make repairs now than to discover a busted line when you go to winterize the system later.

7. Test and Amend Your Soil

If you’re planning any fall planting, September is a smart time to test your soil pH and nutrient levels — most Metro Atlanta soil runs acidic and heavy in clay, which isn’t ideal for a lot of ornamentals and turfgrass alike. Based on your results, working in lime, compost, or a soil amendment now gives it time to integrate before spring planting season ramps up.

8. Plant a Fall Vegetable Garden

Georgia’s mild fall means you’re not done gardening just because summer tomatoes are winding down. September is prime time to direct-sow or transplant:

• Collards, kale, and other leafy greens
• Broccoli and cabbage
• Lettuce and spinach
• Garlic (technically planted a bit later, but bed prep starts now)

A fresh layer of compost or garden soil worked into your beds now will set these crops up to thrive through our relatively mild fall and winter.

Stock Up Before the Fall Rush

Every year, the same thing happens: the weather cools off just enough for everyone in Marietta, Kennesaw, Roswell, Smyrna, and beyond to remember all at once that their yard needs work, and suddenly it’s a mad scramble for mulch, topsoil, and pine straw on the first cool weekend in October. Beat the rush by getting your materials now while supply is easy and the lines are short.

Whether you need a few bags or a full truckload of mulch, topsoil, compost, or pine straw, Mountain High Landscape Supply is stocked and ready to help Metro Atlanta homeowners and landscapers tackle their fall to-do list. Stop by our Marietta yard, or give us a call — we’re happy to help you figure out exactly what your yard needs this season.

Mountain High Landscape Supply proudly serves Marietta, Kennesaw, Smyrna, Roswell, and communities throughout Metro Atlanta with bulk mulch, topsoil, compost, pine straw, and landscape supplies.