5 Things to Do in the Garden This September for a Better Spring

September doesn’t feel like planting season. The tomatoes are winding down, the mower is getting a break, and it’s tempting to call the yard “done” until spring.

But according to university extension offices across the country, September is actually one of the most important months for setting next year’s garden up for success. A handful of tasks done now, while the soil is still warm and workable, pay off big once spring arrives.

Here are five expert-backed garden projects worth tackling this month.

Related: 10 Best Plants for Rain Gardens to Combat Runoff and Erosion

If you want daffodils, tulips, or hyacinths blooming in spring, start planning in September.

According to the University of Minnesota Extension, gardeners should order spring-flowering bulbs and garlic this month, with actual planting timed carefully around local frost dates. The extension advises waiting until the end of September to plant bulbs in northern regions, and until midway through October further south. The reasoning comes down to root development. “Bulbs need to establish their roots before the ground freezes to grow well the following spring,” according to UMN Extension.

Skipping this step, or planting too late, can mean weaker blooms or a delayed start the following year, since bulbs rely on that fall root-establishment period to store the energy they’ll need once temperatures warm back up.

Garlic is one of the few crops that actually wants to go into the ground in fall rather than spring, and September is right in that window for much of the country.

According to the University of Maryland Extension, plant garlic in late September through early November, depending on the region, for a harvest in late June or early July. The extension’s guidance is specific: plant the cloves root end down, pointy end up, spaced four to six inches apart, and covered with one to two inches of soil. Mulching the bed with fallen leaves afterward helps protect the cloves through the winter months ahead.

This timing isn’t arbitrary. Garlic needs a period of cool weather to develop properly before it starts producing leaves and eventually forming bulbs, which is why extension offices consistently list it as a fall, not spring, planting task.

If your spring-blooming perennials, think peonies, irises, or daylilies, have gotten dense and crowded over the summer, September is a good time to thin them out.

Utah State University Extension’s fall garden checklist specifically recommends gardeners “divide crowded, spring-blooming perennials” during this window. Dividing overgrown clumps now gives the newly separated plants time to reestablish their root systems before the ground freezes, which typically means stronger, more vigorous blooms when spring rolls back around.

This task also solves a practical problem: perennials that get too crowded tend to produce fewer and smaller blooms over time, since they’re competing with each other for nutrients, water, and space. Splitting them up in fall resets that competition before it becomes a bigger issue.