A Gardening Checklist for September

It's September, and the season's greatest bounty is mingling with the demise of many plants. Our peppers are ripening to their fullest flavor, pumpkins and winter squash grow fat, and dahlias, tithonia, and morning glories blossom profusely, singing their colorful songs of self-realization. At the same time, death and disease meander through our garden beds freely: tomato vines succumb to various diseases as they move into their later waves of fruit; summer flowers like cosmos, zinnias, and calendula tilt toward seed production and away from bright blooms; and dying outer leaves appear on nearly every crop. This interweaving of life and death energies is ever-present in the garden—dead plants become compost become vibrant young seedlings—but in September it is garishly prolific, as is everything this time of year. Still, there is much to do now that affirms possibilities and sets up future successes—and doing these tasks against the backdrop of September decline fortifies the soul in a way that few other garden tasks do. In the garden as in life, the lesson is the same: keep on sowing!

Sow for Fall Harvests

In northern planting zones, September's cooler temps mean it's time again for sowing Radishes. Leafy greens like Braising Mix, Mesclun Mix, or Salad Savor will thrive, as will Arugula, Mustard Greens, Bok Choy, Tatsoi, Komatsuna (pictured), and Spinach. Plant these crops freely in the early days of the month, but be aware that sowings made from mid-September on will only have the chance to grow to baby-leaf size before the waning light and colder temperatures of October and November diminish their growth rate.

Plant Next Year's Crops

This month, don't forget to order your bulbs! Garlic, Shallots, and many Flower Bulbs will need to be planted in the fall in order to enjoy their bountiful and beautiful rewards the following season. Read all about growing garlic in this blog post. For planning your spring garden, explore our full collection of flowering bulbs here.

Prepare a space in the garden for Poppies, Echinacea, Milkweed and other Fall-Sown Flowers. By keeping a diverse range of annual and perennial flowers growing in the garden, you will invite beneficial insects and have a healthier, better-pollinated garden over all. Order fall-sown flowers now and sow these seeds from October through late winter.

Also sown in September are the few ultra-hardy vegetable crops that we consider "winter annuals." These crops—namely spinach, mache, and wild arugula—can be sown in September and will overwinter as young plants; they will then grow swiftly once spring conditions permit, providing the first fresh green harvests of the season in March, April, and early May.

Give Back to Your Soil

September is the perfect time to sow fall cover crops. Cover crops protect the top layer of soil from erosion, suppress weeds, restore nitrogen, improve tilth, and even feed pollinators. Oats, Field Peas, our Oats & Field Peas Mix,
Austrian Winter Peas, Tillage Radish, and Rye can all be planted in September. For more details on timing and uses for each crop, go to our Fall Cover Crop Planting Chart.

You can further improve the soil by incorporating a late season top dressing of fresh compost. Adding compost will foster better aeration and water retention to benefit plant roots—and for fall-planted crops such as garlic and shallots, it is a necessity.

Protect Your Plants

Want to harvest more from your fall crops? Of course you do. Invest in Row Cover and Hoops to extend your growing season by two to four weeks this year. Read more about season extension here.

Accept the Changes Brought by Fall

The imminent arrival of fall can be challenging for gardeners—especially after this summer, with its smoky June and sodden July. But it is a chance to lean into the softer, quieter energy brought by the darker months—and to remember that plants respond directly to the decreased day length this time of year, as well. They naturally grow more slowly in these shorter days and cooler temperatures. So, keep your expectations in check and take the long view: cultivate healthy soil; plant not just for this season but for the next; protect your crops; and take note of what works for you and your garden.

More Garden Activities for September:

  • On cool and overcast days, divide spring and summer blooming perennials–like daylilies and peonies–and replant. Water in well.
  • Cultivate a section of the garden for fall-sown wildflowers.
  • Browse local nurseries to shop for fall-planted trees and shrubs.
  • Fertilize roses; remove diseased leaves and dead canes.
  • Pot up decorative kale and mums for late-season color.
  • Dig up herbs like Parsley and Chives to bring indoors as potted plants for a sunny windowsill.
  • Dry flowers like Strawflower, Gomphrena, and Love in a Mist to create a pretty fall centerpiece.
  • Read this poem about "September Tomatoes" by Karina Borowicz.