As the weather is cooling off, we’re spending a lot of time pulling in the harvest, saving seeds, and sneaking in a few last-minute fall crops. It’s also an ideal time to divide perennials. Fall’s cooler temperatures and the plants’ natural transition into winter dormancy help to put less stress on your plants.

Why Divide Perennials

One of the main reasons we divide our perennials is to help them thrive. When we divide perennials, we provide more space for the roots to grow. When they’re less crowded, they can absorb more nutrients and water.

Sometimes, we divide perennials when they get out of hand in a particular space. Vigorous plants like Rudbeckia can fill a garden bed and start leaning into pathways and other beds. Dividing them is an excellent way to manage them.

Lastly, dividing perennials means we get more plants! We can share our divisions with friends and neighbors or add them to our gardens. In ornamental gardens, repetition is often a key design element, and dividing perennials is an affordable way to achieve this look. Divisions for medicinal herbs and food crops mean you’ll have larger harvests in the future.

Perennials You Can Divide in Autumn

Not all perennials can be divided, and of those that can, not all of them like to be divided in autumn. Certain perennials, like the fall-blooming chrysanthemums and asters, do best when divided in early spring. These are a few of our favorites to split this season, but we recommend researching what’s best for your plants.

• Rudbeckia (Black-eyed Susans)
• Peonies
• Chives
• Salvia
• Daylilies
• Coreopsis
• Yarrow
• Feverfew
• Butterfly Weed
• Echinacea (Coneflowers)
• Mint
• Lemon Balm
• Skullcap
• Horseradish

It’s also important to remember that dividing your plants will look different depending on the species. Some perennials have traditional roots or fibrous clumps of roots, while others have tubers, rhizomes, or long, tough taproots. 

Tools to Divide Perennials

At a minimum, it’s best to have a sharp spade to divide perennials. Other tools that can be helpful include a garden knife, shears, trowel, a 5-gallon bucket or large nursery pot to carry plants, and a tarp to contain soil if you’re working in a pathway or lawn.

How to Divide Perennials

Use your knife or shears to prune stems and foliage about 6 inches above the ground. This helps to decrease moisture loss.

For plants with traditional or fibrous roots, dig up the plant, getting as much of the roots as you can. If it’s a large patch, you may need to dig just sections at a time, using a sharp spade to cut a section. Once your plant is out, you can divide it with a garden knife or spade. Plants with fibrous roots can be very tough to cut.

When dividing plants like horseradish with long taproots, try to dig as much as possible and include decently sized roots in each clump. For example, horseradish roots should be pencil-sized or thicker to support the plant going into winter. 

Dividing plants with rhizomes is similar. Dig them up, damaging as little of the rhizome as possible. You’ll often be able to pull the rhizomes apart by hand. 

Peonies tend to be fussier than other perennials. While they rarely need dividing, you can split large plants, though the divisions may take two to three years to bloom again. Cut peony roots into sections with at least three eyes.

How to Replant Perennials

Dig a hole 1 1/2 to 2 times its size to give your new perennial the best start. Try to replant your divisions so that the soil is at the same level as it was previously. Peony roots should only be plants about 2 inches below the surface.

Fill in around the roots with a mixture of soil and good-quality finished compost. Pat the soil around the roots gently but firmly. Water your plant deeply and keep up with consistent watering for several weeks, especially if you’re having a dry fall.

If you’re not replanting your perennials immediately, don’t let them dry out! You can keep them for a few days while you decide where to put them or transport them to a friend’s as long as they’re well watered.

Fall isn’t all about the harvest! We’re already dreaming of the summer garden to come. This fall, You can divide perennials to rejuvenate your flowers, share with friends, and get a few more plants growing in your garden. Follow this simple guide to have success dividing your perennials this season.

Fall can feel like a welcome respite after a busy summer season full of vegetables, flowers, and herbs. Even so, some of us can’t help but try to keep the garden bursting with life for just a little longer. Here are some simple fall gardening tasks you can do this season and in future seasons to help your garden stay gorgeous and productive a little longer each autumn.

What Can I Do Right Now?

It may be getting late in the year, but you can still do a few things to make a big difference right now. Give these fall gardening tips a shot this September.

Deadhead Your Flowers

Many flowers will continue blooming until the frost kills them, especially when they’re frequently deadheaded. Keep up with deadheading your cosmos, zinnias, marigolds, chrysanthemums, coreopsis, salvia, and other flowers to keep them blooming and looking fresh.

Sneak in a Few Last-Minute Vegetables

Depending on your location, you may still have a chance to sneak in some last-minute vegetables. Here in Virginia (zone 7), we’re still tucking in radishes, turnips, spinach, and mustards this week. We’ll soon be planting garlic, shallots, perennial onions, and bulb onions. Farther south, folks still have a long list of crops they can grow.

When determining appropriate fall planting times, we recommend that folks use the days to maturity and calculate back from your average first fall frost date. Then, add 14 days to the listed days to maturity for your variety to account for the “fall effect” of shortening days and cooler temperatures. 

Apply Mulch to Insulate the Soil

Applying mulch in the fall will help keep your soil warmer for longer. Around perennials and overwintered greens, mulch will help insulate roots through the winter. For annual root crops like beets and carrots, it can also allow you to leave them in the ground much longer. In some southern areas, leaving them in the ground to harvest them through the entire winter may even be possible.

Invest in Row Cover or Coldframes

Not everyone has the space, time, or money to put up a high tunnel or greenhouse, but don’t let this stop you from adding some season extenders to your garden. Season extenders can completely change your fall gardening game!

Ordering row cover and some wire hoops is a fast way to give your plants a few degrees of protection from cold and frost. Cold frames also provide protection from winter weather, and many people can DIY these with a few cheap supplies like old windows and hay bales. 

Even after September, these are still valuable additions to the garden. We sow very late crops like bulb onions and spinach in cold frames to overwinter and get a quick start in early spring. This gives us larger onions and extra early greens.

Reduce Wind Exposure

In the fall, plants are fighting a battle against dwindling daylight and colder temperatures. Adding winds to the mix means your plants use all their energy to survive. You won’t see them grow and flourish unless you add wind protection. 

Adding windbreak netting or some sort of windbreak can help your plants thrive. You don’t need to stop all the wind; focus on reducing wind speed.

In future seasons, you can improve wind protection by planting windbreaks of trees and shrubs or building fences. 

Fall Gardening Tips to Implement in the Future

If you’d like to do more, there are a few steps you can take before next season that will help your fall garden be even more beautiful and productive. Here are a few things to think about.

Create a Fall Gardening Succession Plan

Great fall gardening starts well in advance! When you’re planning your garden and purchasing seeds, bulbs, and plants, make sure you think about succession planting. For vegetable patches, this means that when one crop finishes, you start a new one to ensure your beds are always full and there’s always something fresh on the table. For example, you might grow a fall pea crop after your corn comes in for the season or plant lettuce once your tomatoes are done.

In a flower garden, the focus is to have some blooming all through the season, including into autumn. Look at average bloom times for bulbs and perennials. Read seed packets for days to maturity on annual flowers. Add this information to a calendar and see how you can fill the gaps. To help extend blooms into fall, plant multiple successions of annuals. For example, continue sowing cosmos and zinnias late into the summer.

Add Larger Perennials, Shrubs, and Trees

If you’re working on an ornamental garden, one thing you can do to keep it attractive year-round is to vary the height and textures. These help add interest when little is blooming. Native trees and shrubs with berries or evergreen foliage can provide interest even into the winter and are excellent habitats for songbirds and wildlife. Shrubs like rhododendron, bayberry, and mountain laurel are good choices, as are trees like magnolia, cedar, and holly. You may also consider some wood ferns and other evergreen or semi-evergreen perennials.

Despite all the hard work that comes with a garden, it can be hard to say goodbye to the fresh food and beautiful flowers when the leaves start to drop. Whether you have a large vegetable garden, herbal medicine garden, cut flower garden, ornamental garden, or a combination, these tips will help you keep growing into autumn and winter.