Mid- to late-August is often an excellent time to plant fall flowers, as long as the weather isn't still so hot that the plants will suffer heat stress.
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.
October is the season to plant spring-blooming bulbs, wildflowers, and many standard gardening favorites. The flowers that don't blossom this winter can spend the cold season in the ground, strengthening their root systems in preparation for a springtime bloom.
Gardening in the fall provides a longer period with more 'good' days, as compared to the often tumultuous spring season. Plus, if you plant in fall you'll end up ahead of the game and won't have to rush to get everything done after winter. In fact, a good strategy is to plant perennials when you plant your fall bulbs.
From early fall through most of November is one of the best times of year to plant spring-blooming bulbs, cool-season annuals and vegetables, as well as many trees, shrubs, and perennials.
Grow an Edible Garden With Fall Vegetables
For a cool-weather vegetable harvest, plant lettuce, collards, carrots, Brussel sprouts, spinach, broccoli, radish, and more. The general rule of thumb is to plant fall vegetables from seed 90 days before the first frost.
Plant wallflowers, forget-me-not, Bellis, Primula, Viola (including winter pansies) and other spring bedding plants in prepared ground or pots.
Think about ways to add color and draw beneficial insects to your fall gardens. Consider planting nasturtiums, marigolds, asters, cosmos, mums, and anemones. Plan out your fall pots and planters. Summer blooms are fading, but there are many opportunities to add color and visual interest to your landscape.
It's time for planting fall color, such as mums and asters, as well as sprucing up planter boxes. You also may be surprised to learn that it's the best time of year to plant perennials and shrubs (trees, too!) while plants still have an opportunity to establish their root systems before the ground freezes.
Starting too soon can result in a weak, lanky plant, while starting too late can give you one that is just not ready for the outside world—both will struggle to survive!
"Fall is an excellent time to plant almost any perennial, with the exception of many ornamental grasses, which are better planted in spring," says Erin Schanen, Troy-Bilt's gardening partner, a master gardener volunteer and creator of The Impatient Gardener blog and YouTube channel.
Flowers to plant in September
English marigold (Calendula) has deep orange petals, which are perfect for a hot border or for cutting. It's easy to grow – from an autumn sowing it should flower from May. Sow direct into shallow drills or on the surface of moist peat-free compost, in pots.
Late summer or early fall is an excellent time to plant mums, one of the symbolic flowers of the season. Practically any time in September that strikes your fancy is a good bet, so long as it's at least six weeks before the year's first frost.
Tip. Mid- to late-August is often an excellent time to plant fall flowers, as long as the weather isn't still so hot that the plants will suffer heat stress. But don't wait too late to plant, or you'll have a very short window to enjoy your flowers. Check the growing requirements for each plant.
Plant Flowers and Vegetables
If you live in a frost-free region, October is a great time to plant cool-weather flowers and vegetables in your garden. Crops such as kale, cabbage, collards, lettuce, carrots, mustard, onions, Brussels sprouts, cauliflower, beets, and garlic can all be planted in early to late October.
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.
It's important to cut back foliage in the fall to protect flowering plants from disease and give them a clean start for regrowth as winter starts to turn into spring. However, there are some plants you can keep around through the winter since they benefit wildlife and still offer visual interest for your home.