Fall is the Best Time to Plant Perennials
Did you know that fall is the best time to plant perennials? Although you can plant perennials at any time of the year, by planting them in the fall they will have time to establish a strong root system (roots will continue to grow as long as the soil temperature is 50 degrees and above) before the cold weather arrives and will come up earlier and stronger in the spring. Plus the cooler air temperatures of fall means that plants will need less water to become well established (although it’s still important to follow a watering schedule for one month).
Most perennials put all their energy into a spectacular flower display over a few weeks in spring, summer or fall. These are great plants and should be included in your garden, but to keep your garden in constant flower with these plants takes a lot of planning (and sometimes supplementing with annuals). I find it’s easier to choose perennials that bloom from spring through fall, giving the garden non-stop color with very little effort. Once these are planted, fill in with the other perennials that you love.
These are my favorites:
Tickseed (Coreopsis spp.) varieties range from super low growing ‘Tweety’ (12” tall and wide) to mid-height ‘Gold Nugget’ (24-36” tall and wide) and the stately ‘Rising Sun’ (4’ tall and 2’ wide). Planted in full sun they will fill the border with cheerful yellow daisy-like flowers from spring to fall.
Blackfoot Daisy (Melampodium) has such cute white and yellow daisy flowers that you’ll be amazed at how rugged and drought tolerant it is. It slowly grows to 12-18” tall and wide and blooms non-stop from spring to fall. The only caution with this plant is to avoid overwatering so that it doesn’t rot.
The gray-green foliage of ‘Walkers Low’ Catmint (Nepeta) emerges in early April in neat, tidy mounds and by May the plant is nearly covered with a haze of lavender-blue flowers. Even after it stops blooming in late fall, the colorful calyces are attractive. Grow it in full sun in a well-drained part of the garden. It will grow to 2’ tall and wide.
Salvias (Salvia spp.) are a must in the perennial garden. My current favorite ‘Mystic Spires Blue’ grows more upright than most (24-30” tall x 18-24” wide) with soft mid-green foliage and clear blue flowers. ‘May Night’ is the second runner up with purple-blue flowers that rise above low-growing foliage (6-10” tall and wide). Both need to be planted in full to part sun for best flower production.
While Autumn Sage is also a Salvia (Salvia greggii), it’s different than most in this genus. It is a woody perennial that is available in a wide range of colors, very drought tolerant and accepting of most soil types. They typically grow 2’ x 2’, but don’t allow them to. If not trimmed on a regular basis, they will become woody and gnarled – and unattractive. They look best and flower more prolifically if cut them back to 6” in February and then again by a third in August.
Pincushion Plant (Scabiosa spp.) is a low growing (1’ x 1’) perennial that will tolerate part shade and average soil conditions. The butterflies love it and it will bloom non-stop from spring until frost if it is regularly deadheaded.
Okay, so Yarrow (Achillea) doesn’t bloom until early June, but it is spectacular throughout the heat and humidity of summer and if deadheaded will bloom until frost. The cheerful flat-umbel flowers are a landing pad for butterflies, and the stiff stems stand tall as long as they are planted in full sun. The new ‘Song Series’ come in a delicious variety of colors and have an abundance of foliage that forms a lovely vase shape.
It’s easy to forget about groundcovers, but they are important in the garden to weave everything together and to cover the soil (keeping it cooler and weed-free). If you need a good ground cover in a partly sunny place in your garden, consider inter-planting Creeping Veronica (Veronica repens) and Dwarf Plumbago (Ceratostiama plumbaginoides). Each low-growing plant (6-12” tall) sports sweet, small true-blue flowers. The Creeping Veronica blooms in early spring and fall until frost, while the Dwarf Plumbago blooms through the early summer to early fall – so you will have continuous bloom spring to fall if you plant them together.
I hope you’re inspired to get out in the garden and plant a few of these perennials!