As your September garden bursts with late-season color from Sedum, Aster, Sunflowers, Zinnias, and more, hopefully you feel a sense of accomplishment for everything you were able to grow this past season. But even as you sit and pause to think about the spring and summer season, as always there is more work to do in the garden!
September is a big month for cold and warm regions alike; regardless of where you are, this month brings an abundance of cutting back, cleaning up, and planting. We call fall the “second season of planting” for a reason! We’ll outline September gardening chores for all regions and highlight tasks specific to hardiness zone.
September Gardening Tasks: All Regions
Weeding. Spend 1-2 hours per week keeping up with weeding in your garden. Diligent weeding helps prevent weeds from going to seed and also prevents disease in next season’s garden.
Stop pruning and fertilizing. At this point in the season, pruning and fertilizing only promotes new growth that most likely will not make it through the winter.
Repot houseplants if necessary and bring indoors. Place them by a sunny window that has good airflow and make sure to check for pests.
If you want annuals to self-seed, stop deadheading in September. Annual Poppies, Zinnias, Sunflowers, and more will drop their seeds and (most likely) come back next year.
Leave Echinacea, Sedum, Grasses, and Clematis alone to provide habitat and food for birds over the winter months. These blooms also add texture and interest to the winter garden.
Write in your garden journal. Take note of what grew well, dividing your gardens up into sections as it makes sense (containers, vegetable garden, annuals, perennials). This will be a big help when you are planning your garden over the winter months.
Start cleaning up plants as they fade. Cut back any perennial that is diseased or that has started to turn yellow, including Daylilies, Iris, Peonies, Bee Balm, and more.
Dig up/divide Daylilies, Iris, Hostas, and more in September if they have become overcrowded or outgrown the space.
As you cut plants back and continue to weed, top up mulch in all of your garden beds to provide a nice layer of protection for the winter months.
Plant cover crops. As you finish harvesting tomatoes, beans, zucchini and more, build your vegetable garden soil for next year by adding quick-growing cover crops. Plant Clover,Vetch, and Austrian Winter Pea as “green manures” to help build nutrients and get the soil ready for next spring’s planting.
Add perennials and spring-blooming bulbs to your garden in September. Perennials planted in the fall offer up bigger growth and often bloom in the first season. Bulbs like Tulips, Daffodils, Allium, and more need the overwintering period in order to bloom in the spring.
'Breaking Point' Reblooming Bearded Iris features a striking broken color pattern, bringing excitement to the mid-to-late-spring garden. Crisp white standards have a hint of warmth near the gold beards, and royal purple falls have showy silvery-white streaks. Each stem produces up to nine gently ruffled flowers, reblooming in mid-fall. Blooms are surrounded by upright sword-shaped foliage. (Iris germanica)
'Society Page' Bearded Iris will be the talk of the neighborhood with ruffled lacy pink blooms. Flowering from early to late spring, its delicate pink petals have faint green veining, complemented by strapping upright foliage. This award-winning Bearded Iris is easy to grow in sunny beds and borders, offer delicate beauty in a low maintenance perennial that will brighten you spring garden for years to come. (Iris germanica)
'On Deck' Reblooming Bearded Iris stands out with vividly contrasting blooms. Ruffled white standards are accented with hints of gold, and falls streaked with cobalt blue. This reblooming variety opens in late spring, with a repeat performance 'On Deck' in late summer or fall. A low maintenance beauty with upright lancelike foliage for added texture after flowers fade. (Iris germanica)
Tall, dark, and handsome, 'Señor Jinx' Bearded Iris will enchant you with velvety black blooms. Emerging in mid-spring, upper petals show just a hint of purple above the opulent coal-black falls. 'Señor Jinx' holds up to seven ruffled flowers per stem, each with a bright yellow beard to draw your eye into the ruffles. Upright lancelike foliage adds texture to beds and borders for low-maintenance beauty. (Iris germanica)
Direct-seed spinach, lettuce, beets, and carrots for a last round of winter crops.
Order spring-blooming bulbs like Tulips, Daffodils, and more. Refrigerate bulbs for 6-8 weeks to “force” the wintering over period they need in order to bloom. Plant outdoors (or in a sunny spot indoors) in the early winter.
September Gardening Tasks: More Work Now, Less You’ll Have To Do In Spring
The more you accomplish in the September garden means less for the early spring when you’re busy with the long list of to-dos to wake your garden up for the season. If you’re thinking of adding a pollinator garden to your landscape, try to prep the area and get as much planted as you can this fall. Come spring, the plants will be much larger and that area will be primed and ready to add in annuals and other varieties. The more weeding and mulching you do in September, the less weeds you’ll have to deal with in the spring. Take advantage of the gorgeous weather that September brings most of the country and get yourself in a great position to start next season off running!
Saffron is worth its weight in gold, so it pays to grow your own! These beautiful purple crocus flower in fall and offer you pure, prized edible saffron on each flower's stigmas. Easy to grow and exceptional in containers. (Crocus sativus)
Glistening pure-white crocus flowers sparked with orange and yellow anthers catch everyone's attention against the deep-blue skies of autumn. As welcome in fall as the famous white crocus is in springtime. (Crocus kotschyanus)