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.
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.
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.
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.
Perennials can be planted any time of year.
By planting them in the fall, plants will have a long time to establish a strong root system before the hot, dry summer months. In fact, the roots are likely to continue to grow as long as the soil temperature is over 50 degrees Farenheit.
It's common to think that everything should be chopped down to the ground in the fall, but some perennials actually need their foliage to protect new shoots through the winter. Other varieties offer up important habitat for local wildlife and some perennials provide height and interest through the winter months.
The newly emerged growth of most perennials can tolerate temperatures in the low 30s and upper 20s Fahrenheit. Freeze damage may occur if temperatures drop into the lower 20s or teens. Most well-established perennials that have been damaged by freezing temperatures should survive.
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.
Fall is a great time to plant another crop of spring greens such as spinach, leaf lettuce, arugula, mustard greens, and mâche because they require cooler soil for seed germination and they mature quickly.
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.
Divide fall blooming perennials in the spring because
New growth is emerging and it is easier to see what you are doing. Smaller leaves and shoots will not suffer as much damage as full-grown leaves and stems. Plants have stored up energy in their roots that will aid in their recovery.
Transplant perennials when the weather is cool, even a little rainy, if possible. Early spring and fall care are best times for transplanting. Then the weather is cooler and the plants are not using as much water. “However, don't move or transplant perennials while they are in bloom,” he says.
Perennials are slow growers at first: They take the first one to three years to establish deep roots and dense foliage. However, once established, they thrive with little maintenance to give your yard beautiful new growth year after year.
Also, do not cut back hardy perennials like garden mums (Chrysanthemum spp.), anise hyssop (Agastache foeniculum), red-hot poker (Kniphofia uvaria), and Montauk daisy (Nipponanthemum nipponicum). Leave the foliage. It's important to protect the root crowns over winter.
Some Hardy Perennials Need Winter Protection in the North and Midwest, and Tender Perennials Require Special Protection Methods. Many perennials hardy for your zone make it through winter just fine with no special attention.
Many gardeners cut back their perennials much too soon. There are nuances specific to certain perennials that dictate whether it is better to cut them back in fall or spring, but the general rule I like to follow is to only cut back perennials that start looking bad in fall.
By dividing the plant when it is not flowering, all the plant's energy can go to root and leaf growth. Fall division should take place between early September in the uppermost Piedmont and mid- to late October on the coast. Allow at least four to six weeks before the ground freezes for the plants to become established.
Answer: Late summer (late August to mid-September) is an excellent time to plant many perennials.
'Autumn Joy' is a perennial flower that blooms all year and that can be grown in zones 3-9 across the variety of climates that can be found in these zones. This sturdy sedum provides the landscape with reddish-pink flowers in late summer.
Prepare Soil
Add as much organic matter to your planting area as you can. Use things like compost, old leaves, mushroom compost, shredded bark mulch, bark fines or composted manure. Perennials live in the same spot for many years. Adding lots of organic matter creates a base that helps plants thrive.