Late summer and fall are ideal times to plant perennials that flower in spring and early summer. When you plant in the fall, early-season bloomers have a chance to built root systems and establish vigor -- which will show up in the following year's bloom.
Some Plants Are Especially Cold Hardy
Many cold hardy perennials, shrubs and trees are excellent candidates for fall planting. In general, plants with USDA cold hardiness ratings of 3, 4 and 5, are the best candidates for fall transplanting in cold winter climates.
Plants like chrysanthemums, nasturtiums and asters are wonderful choices for seasonal planting arrangements. While perennials that will survive the winter are great choices, autumn is also a great time to explore new ideas will short-season annuals too.
Asters. These beautiful fall-flowering perennials are a lovely companion planting to chrysanthemums, the other stars of the autumn garden. Give asters full sun, and water to get them established (but don't overdo it; they don't like soggy feet).
For this Blooming Period, we're highlighting some late summer/fall favorites: callas; China asters; lisianthus; perennial sunflowers; and zinnias.
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.
Violas and Pansies
These hardy little flowers not only have gorgeous blooms but can survive almost anything winter has to dish out. Violas and pansies grow best in partial shade but need a minimum of four hours of sunlight a day.
Spring-blooming perennials, especially in the bare root form, are best planted early in the fall. Planting in the fall while the soil is still warm will give the roots enough time establish properly. This allows the plants to emerge from well established roots, with a stronger start, the following spring. 4.
Planting. Most perennials should be planted in the fall or early spring. Fall planting gives the plant more time to become established before the start of active growth in the spring. Fall-planted perennials are usually well-established before hot weather.
And some of the annuals that are normally considered spring flowers will flourish in the cooler fall weather, if only for a short time. Mums, specifically florists' or garden mums, have become the go-to plants for a fall garden.
There are a few bulbs that are winter blooming flowers. Dainty and delicate, snowdrops (Galanthus) are true spring harbingers. No bigger than a dandelion, they bravely push through snow and even ice to grace the garden with their dangling white bell blooms.
You can transplant perennials anytime until the ground freezes in the fall, or wait to transplant them in the spring. Fall is an excellent time to transplant herbaceous perennials because your plants will then have three seasons to establish a good root system before hot summer weather sets in next year.
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.
For starters, spring-blooming bulbs should be planted in fall. Trust us: You'll be glad you planned ahead when you see them pop up after a long, dark winter! Get them in the ground any time before the ground freezes, which is from October to mid-December, depending on where you live.
Answer: Late summer (late August to mid-September) is an excellent time to plant many perennials.
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.