Updated in 2025

After summer’s heat, drought, fires, bad air and occasional dumps of rain, September can be a challenging time for many northern gardeners. However, by month’s end it can also be one of the best months in the garden. The frenetic activity of early summer to get things started and the heat of July and August are behind us. But that doesn’t mean there aren’t things to do.

Here are 10 September garden tasks to tackle.

Purchase and plant bulbs

This is a top fall chore that makes spring so much more pleasant. Think about where you wanted some color last April or May and put a few clumps of bulbs there. Some of our favorites are a combination of daffodils and crocus, which emerge earlier than most.

Clean up spent/diseased vegetables

If your tomato plants have blight or septoria leaf spot and production is diminishing, it might be time to pull them. Don’t compost diseased plant material unless you have a compost pile that gets really hot. Pull the plants and throw out the debris.

Plant something fast-growing

If you have a hole in your garden, you might want to plant a quick-growing lettuce, arugula or radish. Some vegetables can take a bit of frost and grow fast enough to give you a crop before the end of October.

Plant a cover crop

You may want to even plant a cover crop to nourish your soil for next year’s garden. These crops are planted late and then turned over in spring. The University of Minnesota has some great advice on cover crops.

Plant a tree

Fall is the best time to plant a tree in your yard. It’s easy on the tree and you may get some great deals at the nursery. Two things to remember when planting trees: don’t go too deep—you want to see the root flare above ground—and make sure to water it (probably daily) for at least six weeks.

Your nursery or garden center will probably have a guide for you to follow. Here are some recommendations for trees that will do well over the next few decades (yes, think decades!) in Minnesota.

Plant perennials

It’s not too late to divide or even plant perennials, too. Don’t give them too much fertilizer, but make sure they are adequately watered through the fall.

Add a fall container

A fun activity to put on your September garden chore list is adding a fall container. Mums, decorative pumpkins, ornamental kale—whatever you like to add something fresh to your front porch or stoop.

Start garden clean up

I try to leave up as many plants as I can for pollinators through the winter, but some parts of the garden need cleaning up. Deadhead. Pick your weeds. Remove dead vegetable matter. You’ll be glad you did once next spring arrives.

Start transitioning houseplants indoors

One important September garden chore is to start transitioning any houseplants that may have spent the summer outside back into the house. You’ll want to clean plants and the pot and make sure there are no bugs on it before bringing them indoors. Our friend Amy from GetBusyGardening.com has a great post on how to clean and debug your pots.

Take care of your lawn

Early fall is a great time to fertilize, spread seed or patch your lawn, apply broadleaf weed control, thatch or aerate, if any of those are on your agenda. The University of Minnesota has great information on when and what to do in the lawn.