By Susan Martin for Proven Winners
Photographs courtesy of Proven Winners
Rosy flowered sedums are in full bloom in many places across America right now, lighting up landscapes with their prolific blooms that help to sustain pollinators late in the growing season. If you are considering picking up a few for your own garden, now is the best time. Sedum is one of five perennials we’ll share here that actually prefers to be planted in the fall. Let’s take a closer look.
When it comes to perennials, the “Fall is for Planting” slogan certainly applies. We spoke with Laura Robles, Perennial Trials Manager at Walters Gardens which is one of the largest perennial growers in the U.S., to get her take on planting perennials in the fall.
Robles advised, “The weather and soil conditions in fall make it the perfect time for planting perennials. Cooler air temps and more frequent rainfall make for an easier adjustment period, and soil temperatures are warmer in fall than they are in spring, which is more ideal for root growth. Planting in the fall also tends to result in a larger plant in a short amount of time, since plants will reemerge larger in the spring after their winter dormancy.”
Trials conducted at Walters Gardens have shown that planting the following perennials anytime between when the summer heat breaks and a month before the ground freezes can be beneficial: goatsbeard, brunnera, tickseed, daylily, hardy geranium, baby’s breath, perennial sunflower, hosta, tall bearded iris, shasta daisy, ligularia, bee balm, Russian sage, phlox, sedum, spike speedwell, columbine, peony, poppy, primrose, lungwort, salvia and foamflower.
Let’s take a closer look at five popular perennials from this list.
If you can find them in the fall, snap up a few bee balm plants to get settled into the garden this time of year. This hardy perennial needs to be exposed to cold winter temperatures in order to produce flowers the following year (a process called vernalization). You will also find that bee balm nearly doubles in size the following season if you plant it in the fall rather than in the spring. Giving it that extra head start really makes a significant difference.
By planting different types of bee balm, you can have them in bloom all summer long. Choose the early blooming ‘Leading Lady’ varieties to see color from early summer into midsummer. Pair them with the later blooming ‘Pardon My’ varieties to extend the show through late summer.
Phlox is a diverse genus of perennials which includes many species of spring blooming groundcovers and summer blooming upright forms. In our trials, all have benefitted from being planted in late summer or fall.
Generally, most types of spring blooming perennials do very well when planted in the fall. Groundcover phlox like Mountainside™, Sprite and Spring Bling™ is no exception. It will reward you with a broader carpet of color in spring when planted the fall prior. Upright types will also bulk up faster when planted in fall, meaning the clump will re-emerge with more stems the following spring. More stems will result in a splashier floral show in summer.
Garden centers are often fully stocked with fall blooming sedums from late summer on, which is perfect timing for fall planting. If you buy a 1-gallon container of upright sedum, the plant may have five to eight stems comprising the clump. Each stem arises from an “eye” on the crown of the plant. In the spring, these look like tiny green rose buds emerging from the soil.
When planted in the fall, you can expect your sedum to have 30-50% more eyes the following spring because you gave it a head start. By comparison, if you plant that same exact pot of sedum in the spring, it will stay the same size the whole season.
Daylilies that bloomed earlier in the summer may be off your radar come fall, but planting them now will reward you with larger plants that produce more flower scapes next summer. We’re especially fond of the Rainbow Rhythm® collection of unique and reblooming varieties.
Don’t be dismayed at yellowing or drooping daylily foliage when you see them for sale this time of year. The plant is focusing on sending its energy back down into its roots for winter storage. It will re-emerge next spring as a bigger plant with more fans (sets of leaves) and more flowers to enjoy. Fall is also a great time to divide any daylilies you have in your garden already and transplant or give away the extras.
Anyone who has grown hostas knows what incredibly hardy perennials they are. You can plant them almost any time of year without much trouble. However, planting hostas in late summer or fall is beneficial because it helps them form a stronger root system, results in larger, more robust growth the following year, and spurs the development of mature traits like rippled edges or thicker leaves. It can take five years or longer for a hosta to grow to its expected size and show the qualities that make it unique. Planting in fall will help your newly planted hosta reach maturity a bit faster.
No matter which perennials you decide to plant in the fall, it is important to keep them watered until the ground freezes. Remember, their roots are continuing to grow through the fall months while the soil temperature is still relatively warm. Mulch fall planted perennials with a thick layer of shredded leaves or bark. It will help to keep the ground warmer longer, giving the plants’ roots more time to get established before winter. Once your perennials are all tucked in for winter, there’s nothing left to do but dream about how beautiful they will be next spring!