That assumption wouldn't be wrong, but I'm going to let you in on a little secret: you can also plant a lot of seeds in the fall and they'll come up even earlier in the spring. Tons of annuals drop their seed in the fall anyway, and the seeds are naturally cold-stratified over the winter.
Fall planting will be much easier, so you should aim for getting your seed down late in the season, but before the ground freezes entirely.
Fall Planting for Spring Harvest
Spring greens such as spinach, leaf lettuce, arugula, mustard greens, and mâche are great for fall planting because they require cooler soil for seed germination and they mature quickly.
September is a great time to plant those fall flowers. There are many varieties that can be planted this fall to start blooming early spring.
For April, May or June blooms, plant seed directly outdoors August-October. For June, July, August and/or September blooms, plant your seed outdoors March-June. Seedlings normally tolerate a light frost.
Mid to late summer is the time to start sowing your fall garden plants if you're looking to bring fresh veggies to your table by the time the cool weather arrives. Crops like broccoli, pictured, can be sown in late summer for a fall harvest.
You can plant grass seed in the fall to get it to grow in the spring through a process called dormant seeding. This type of seeding is done by putting down seed while the ground is not yet frozen but is still cold enough to prevent seed growth until the spring.
Choose your site and best planting time.
Planting should be done AFTER a killing frost in your area, or after you're quite sure the growing season has ended, and your seed won't sprout until spring. In heavy winter areas, that means from late September or October up until the ground freezes.
Tap Down. Wildflower seeds don't need to be planted in holes; however, they should be tapped down to encourage growth. After you've scattered them over the soil, use the back of a shovel, your hand, or your foot to gently press them into the ground.
Although each plant's needs may vary and some will be more winter-hardy than others, in general about a month before the last fall frost is sufficient in giving the plant enough time to establish itself and take root.
Autumn is a great season for annuals, low-maintenance perennials and evergreen shrubs to shine. In fact, some of the most popular flowers, like colorful mums, roses, dahlias, purple pansies and yes, even bright yellow sunflowers, all bloom around September and October.
Up come spring bulbs, such as daffodils and crocus, followed by perennials, such as dianthus and garden phlox. When you plant early (in autumn), your perennials flourish faster in spring and summer.
Yarrow is one of the longest flowering perennials that grows best in full sun with well-drained soil of average fertility; over-fertilizing can cause the stems to flop over. Flower colours can range from soft pastels to rich jewel shades. Deadhead spent flowers by clipping the flower stem back to the main foliage.
It can take from two to four weeks for grasses to grow in October, especially if it is a warm-season grass. Cool-season grasses can still germinate and take root in the cooler temperatures of late fall, though you might not see their full potential until spring.
Benefits of Dormant Seeding
The seeds will germinate in the spring before spring seeding does and therefore will be stronger and better able to survive the heat of summer. Plus, preloading your lawn with some good grass seed to compete with the weeds in the bare spots is a great way to help your lawn look its best.
Fall is the perfect time to plant wildflowers. You'll follow Mother Nature's cycle - flowers naturally drop their seeds in the fall, and they overwinter, then germinate and bloom in spring. Fall planting is an especially good time to plant in areas where you want to conserve water.
Watering Thoroughly, but Not Too Much
Once the seeds have been properly sown and lightly incorporated into the existing soil, water the area thoroughly and leave until next spring. By this time of year, our cool to cold temperatures and short days will help keep the areas moist far longer than in summer.
Spring seeding is an option; just not the best option for maximum seedling establishment and growth. Consider seeding in the Fall. Sure, summer is over and the last thing most of us want is more lawn work! Still, with cool nights, warm days and light fall rains, this is truly the best time to plant seed.
Petunias, poppies and sunflowers have been recognised as some of the fastest growing flowers, taking only a fraction of the time to germinate and bloom compared to some of the more challenging plants.
It takes about two weeks for most seeds to germinate, while other seeds can take much longer. Seeds should sprout growing within a month of planting when sown in the right conditions.
It's never too late. It just matters what you put into that garden. It's too late to grow tomatoes in your Chicago garden in September because you'll be getting cold weather soon, but you could still grow carrots, radishes, and lettuce plants.