Why is fall best for planting?

Jason Holmes, center, 

advises customers about plant selection

at last year's Fall Plant Sale

By Jason Holmes

Ahh, the season of fall is almost upon us, and we gardeners are coming out of summer semi-hibernation, during which we emerged only to water the plants we planted in early spring, hoping they made it through those hot, dry summer months.

Many of us know that fall is the best time to plant shrubs and trees. We hear it all the time. But let’s face it, we see plants we love, with those nice big flowers or that beautiful combination we just have to have, and that sage advice sometimes gets forgotten. For me, buying plants in spring is often an impulse, and I spend much of my time watering those plants on 90- to 100-degree afternoons.

People often ask, “Why is fall the best time to plant?” The answer is simple: As the plants go dormant above ground, roots will continue to grow underground until the ground temperatures fall below 40 degrees Fahrenheit.  So for most of the country, this statement is true from mid-September through mid-December.

Here is an example: if you plant a tree in the spring, it must acclimate to the new site, producing new growth like leaves, flowers and sometimes fruits. It must also produce roots as well! This means you will need to water more often while your tree acclimates to its new situation before the summer heat and often dry weather arrives. Now, plant the same tree during the fall, and soon after the plant will begin to go dormant above ground, but the roots will still have several months to continue growing underground. This is giving the plant a “head start” for the next spring as it produces strong new growth.

Annuals and perennials are great to plant during the spring and fall. As long as they are watered until they are established, they fare very well. I love to plant perennials in the spring, as they are waking up from winter dormancy, because they grow to fill in a space quickly. Perennials are often faster to grow into a space as opposed to trees and shrubs, and this gives us a chance to plant these in both seasons. So it is simple: anyone can plant anytime they want. I just hope I’ve explained well enough why fall is so ideal.

To help prepare you for your fall planting blitz, Sarah P. Duke Gardens will have its Fall Plant Sale on Saturday, Sept. 29, from 9 a.m. to noon. We will have a great variety of bulbs that bloom in late winter to early summer, fantastic perennials, useful herbs for cooking, and many unusual shrubs and trees, too. Many of these plants are propagated from Duke Gardens by dedicated staff and volunteers, who will be there to answer any questions you may have about gardening or plants in general.

If you want first dibs on all the plants, consider joining Friends of Duke Gardens, so you can attend the member pre-sale at 8 a.m. Non-members can join on site. Or call 919-668-1711 to join in advance. We hope to see you there.

Sarah P. Duke Gardens creates and nurtures an environment in the heart of Duke University for learning, inspiration and enjoyment through excellence in horticulture. The Gardens is at 420 Anderson St.

Columnist Jason Holmes is curator of the Doris Duke Center Gardens at Sarah P. Duke Gardens. This column first appeared in the Durham Herald-Sun.

Spring Plant Sale Preview

Plants from Duke Gardens are always
popular at the Spring Plant Sale

By Kate Blakely

Springtime is a lovely mix of old and new. Old favorite bulbs are sprouting. And gardeners begin scouting out new possibilities for that extra special spot in the garden. Whether you’ve made a tradition of it or it’s your first time visiting us, the Duke Gardens Spring Plant Sale is always a wonderful opportunity to celebrate spring.

Every year Duke Gardens gathers a great variety of plants to offer for sale. This year, the sale will be Saturday, March 31, 8 a.m. to noon, with a preview sale for Gardens members Friday, March 30, from 5 to 7 p.m. (you can join on site).

Many of the featured plants have been propagated by volunteers on the Gardens’ propagation team. Gardens staff members, volunteers and members of the Durham Master Gardeners will be on hand and love to answer questions and provide advice for all your gardening needs.

Here’s a preview of some of the new and old favorites you’ll be able to find at the sale this year.

Purple-leaved smoke bush (Cotinus coggygria 'Royal Purple'): This is an unusual plant of Chinese origin, and it sells out almost every year. The multi-stem shrub can grow up to 12 feet high. Its new growth and foliage provides a splash of purple or burgundy color in the garden.

“They produce flowers in a large panicle that’s open and fluffy,” says Jason Holmes, curator of the Doris Duke Center Gardens. “That’s what gives them the appearance of smoke in the distance. It’s a real unique oddity that would fit well into a woodland landscape.”

Hostas: Hostas always generate interest in the garden, and you’ll see some new varieties at the sale, including ‘Autumn Frost’ and ‘Heat Wave’.

“ ‘Autumn Frost’ is a uniquely blue-foliaged hosta with an awesome variegation through the mid-vein,” says Holmes.

‘Heat Wave’ is certainly the best way to describe our southern summers. During the spring, this hosta has chartreuse centers with blue margins; then in summer the center brightens to gold and the edges turn blue-green.

“If deer are a problem and you love hostas,” Holmes says, “I would try them in a container on your deck or close to the house.”

Roses: If you’re looking for a hardy rose, don’t miss the Rosa chinensis ‘Mutabilis.’ This no-spray rose is a very heat-tolerant cultivar, said Holmes. It also stands up very well against insects and doesn’t appear to get diseases. It will bloom from the beginning of May through November, and you won’t even have to deadhead it. The Rosa chinensis will respond well to a little pruning during the winter months. All in all, it’s an easy-care favorite.

The sale will also feature a wonderful variety of herbs and vegetables, including squash, zucchini, fennel, dill and peppers, as well as heirloom tomatoes. It won’t include craft vendors, but it will feature additional plant vendors, with diverse offerings and areas of expertise. (See more info on our plant sale page.)

At the sale, plants will be marked with signs noting whether they’re drought- or deer-resistant. The Duke Gardens-propagated plants will also be marked; you may want to head there first, as people love bringing a little piece of Duke Gardens home to their own gardens.

A final thing to keep in mind is that because the sale is earlier this year than previous years, you should refrain from heading home and planting right away. Keep your new plants indoors until the last frost date, April 15.

For more information about the plant sale, Gardens membership or other Duke Gardens classes and public events, please go to gardens.duke.edu. To join Friends of Duke Gardens in order to attend the preview sale, please call 668-1711.

Sarah P. Duke Gardens creates and nurtures an environment in the heart of Duke University for learning, inspiration and enjoyment through excellence in horticulture. The Gardens is at 420 Anderson St.

Kate Blakely is a graduate student at Duke Divinity School and a work-study assistant at Duke Gardens. This column first appeared in the March 17 Durham Herald-Sun.