Spring is the ideal time to divide many of your perennial plants. As the weather warms up and daylight hours increase, your plants will enter their rapid-growing phases. Dividing at this time can make a big difference in how well they re-acclimate and whether they thrive in the long term. 

When plants enter their active growth stage, we see those lovely new leaves and branches start to form. Underground, the roots are doing the same thing. Dividing them now means they will have all of that active growth time to establish roots before they face dormancy in the fall. 

Hosta

These big leafy beauties thrive where the sun takes a break.

Hostas are beautiful foliage plants that work excellently in the shadier parts of the garden. They’re easy to care for and make a statement with their large, tropical-looking leaves. Dividing them is best in the spring as they first begin to put out new growth. Don’t dig them up too soon; wait until you see some new leaves. 

Dig up the entire plant gently, and shake the dirt off so you can see the roots clearly. Look for points where new growth appears. Use a knife to divide sections of the root system, making sure that each cutting has some of these points. Then plant them again and enjoy even more lovely leaves this summer. 

Yarrow

It’s wild how fast it spreads if you let it.

Yarrow is the same in that you want to wait until you see some new leaves appear before you set to work. This perennial is tough and multiplies, so it’s good to spread them out in the spring. Every two to three years is ideal to keep them healthy and vigorous. 

Yarrow can handle division quite well. Dig up your roots, and use a sharp knife. A larger, heavier tool is not necessary. Identify the individual clumps of plants and use your knife to cut any roots that you can’t untangle by hand. You can put some of your divisions in pots to get larger or put them right in the ground. 

Blazing Star

They’re surprisingly easygoing once you get them in the ground.

Blazing star is an excellent perennial for pollinator gardens. Bees and butterflies love their fuzzy purple flower spikes. They look spectacular in a grouping with their blooms and textural foliage. As soon as you see those bits of leaves start to peek out of the soil, the time is right. 

Liatris, or blazing stars, grow from tuberous roots. You may also hear them referred to as corms. Sometimes, they produce offsets, which you can easily break away from the central corm. If there are tight clusters, you may need to use a sharp knife to divide this perennial. Make sure that each division has at least one eye or growth point. Plant them all in loosened soil, about one foot apart. 

Swamp Milkweed

New growth usually appears around mid-spring.

Swamp milkweed is a native variety throughout much of the eastern and central United States. It’s also an important food source for monarch butterfly larvae. While most milkweeds don’t require separating, this is one that you can divide to help keep your plants strong and vigorous. It will spread by seeds and rhizomes, though, so dividing is only necessary if you want to move it around to other areas without starting from seeds. 

This one has a deep taproot, so it’s a bit more difficult. Make sure to dig deeply and avoid breaking that root. Use your hands to separate sections of roots with top growth attached. By mid-spring, this one should be showing some resurgence of growth. 

Toad Lily

Shady corners get a little magic when these show up.

Toad lilies are another great perennial for the shade garden, and they can be divided throughout spring and summer. Their lovely foliage and unique flowers make them a favorite in my shaded spaces. The blooms resemble orchids with their splashy colors, and they smell nice, too!

They are easy to divide, and spring is a great time for it. As soon as new growth emerges, dig up your clumps and either cut or pull apart clumps to replant. Some clumps will come apart easily, while others may require more effort. Depending on the size of the perennial sedge that you’re dividing, take along a sharp knife or small axe. 

Garden Mum

A little root shuffle now means a bigger fall show.

Fall is mums’ blooming season, but spring is the time to divide your plants. This gives them all summer to grow big and beautiful, setting buds and setting down strong roots. Dig up the entire root system and shake out the soil so that you can see it clearly. 

When you divide your garden mum roots, each section should have two or three stems attached. This will ensure shrubby, lush plants when blooming time rolls around. For best results, replant them immediately in a similar location. The crown of the mum should sit just slightly below the soil level.

Maidenhair Fern

Proper cuts ensure strong, thriving ferns later.

Spring is re-potting time for maidenhair ferns, and for those in the ground, it’s the ideal time to divide. If you want to propagate your potted ferns, this is the perfect time to do it. It minimizes the stress that can result from disturbing the roots multiple times. 

Examine your roots for naturally weak spots or places that look easy to separate. Use a sharp knife to make clean cuts to the root tissue. Each division should have several shoots and a substantial portion of roots attached. Keep them well watered, and be patient. It can take a bit of time for them to recover and put on new growth. 

Delphinium

Ensure growth points face up for vibrant new growth.

You can split delphiniums in fall or spring, but since we are in spring now, we will assume that you didn’t split them last autumn. These beautiful bloomers are wonderful as ornamentals and in the cutting garden. They are clump-forming and grow from a system of tubers under the earth.

Dig up your clumps of tubers and break away any sections that come apart easily. Make sure they have growth points or some green growth. If the clumps are large, you can use your shovel to split them into more manageable sections. Put them back in the ground with the growth points facing up.

Beardtongue

For uniformity, aim for similarly sized root sections.

It’s getting late to divide your beardtongues, so if you’ve been holding off, now is the time. These begin growing early, and you don’t want too much growth before you separate them. This way, they still have plenty of energy to apply to setting down strong roots. 

Lift the roots out with a garden fork or a spade. Use your spade or a blade to chop the clump of roots in half. For the sake of uniformity, try to split the roots into sections of a similar size. When you replant them, they will have a nice, even appearance. 

Aster

Three to four years is a good time for separation.

Asters don’t require frequent division, but over time, they may become crowded. To keep individual plants healthy and vigorous, you’ll want to do this about once every three to four years. You’ll need a spade shovel and a knife or a small hand saw to do the job. 

Dig up the root system and cut it into sections. Ensure that each section has both roots and foliage and replant them immediately in their new locations. 

Coneflower

Spring division encourages bigger, stronger plants for the season.

Similar to asters, coneflowers don’t require division often, but they can become crowded over time. It’s good to split them up every three to five years and give them room to breathe and stretch out. Overcrowded plants will lose their vigor due to nutrient deficiency. 

You can divide perennial coneflowers in spring or fall, but spring division will result in faster growth and larger, stronger plants going into the winter. For most, you can pull the root sections apart with your hands. Equip yourself with a sharp knife just in case they don’t come apart easily. 

Sedum

Dig up the roots and give them room to breathe.

Sedum is an incredibly easy plant to grow and care for. It’s drought-tolerant and tolerates a lot of sun and heat without complaint. It’s a great perennial for warm climates. Divide your sedums every three or four years to keep them happy and healthy.

You can separate them after they bloom, but spring is an ideal time, when they first begin to grow after winter. Simply dig up the entire plant with its roots attached. Use a sharp knife to divide it into four-to-six-inch sections and replant, giving each section some additional space. 

Daylily

Divide the clusters to prevent overcrowding and nutrient competition.

Daylilies can become overcrowded, so you should split them up about once every three years. Otherwise, you’ll end up with tight clusters that compete for nutrients and don’t flower as well. You can propagate this way in spring or wait until they finish blooming in early fall. 

Dig up the thick clumps of roots and examine the way the fans of leaves connect to each other. You can split off each fan separately or keep them in pairs. Usually, it’s possible to split these apart by hand, as each fan will have its own root system. 

Hollyhock

Handle with care to preserve their deep taproots during transplant.

Hollyhocks have long taproots, so division is not the most effective method of propagation. However, you can still divide this perennial, and now is the right time to give it a try. You’ll want to dig down deep and be careful about damaging that tap root. Plants that have this type of root are temperamental about transplanting. 

If the plant is taller, cut back the foliage to about six inches. Do this from underneath, making sure that each portion has some roots attached. Replant them right away to reduce stress.