Do you often wonder whether you should be splitting and transplanting your perennials in the fall or the spring? I’ve created a guide that includes some of the more common plants below, with the best times for dividing perennials, and how to do so.
Timing is Key When Dividing Your Garden Perennials
Timing and technique are so important when it comes time to divide perennials.
Many perennials can be divided in either early spring or early fall, but some plants can be very sensitive to when they should be split.
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I’m a self-taught hobby gardener, not a Master Gardener. Everything I share with you on my blog is my personal opinion and things that worked for me along the way.
Reasons to Divide Your Perennials…
- Keeps the plant healthy by giving the plant more space for the roots to grow, and absorb nutrients and water.
- Increases the number of flowering blooms.
- Manages the size of the plant and keeps it from overcrowding others in the garden.
- Keeps the plant from dying out in the middle and leaving a bare hole by dividing it every 3-4 years.
- Creates more plants for future plantings in your garden and to share with others.
I’ve listed some of the most common garden perennials, and the most optimal times to divide them using the best methods for each.
Perennials to Divide by Hand
|Bleeding hearts||Spring||Divide after the plant flowers|
|Dianthus||Spring, Summer||Mat-forming types root as they grow; cut a rooted piece from the edge and replant|
|Hellebore||Spring||Divide when plants are in bloom, or right after they stop flowering|
|Lady’s mantle||Spring, Fall||Easier to divide in early spring when you start to see the leaves emerge|
|Lamb’s ear||Spring, Summer, Fall||Roots are along the stem; cut a piece off the edge and replant; cut leaves back by half|
|Primroses||Spring||Transplant after the plant has finished blooming|
|Salvia||Spring, Fall||Divide every 5-6 years or when the plant dies out in the center; divide in the spring in cold and winter climates.|
|Yarrow||Spring, Summer||Easy to divide; most types spread quickly and should be divided every 2-3 years|
Perennials to Divide With a Spade or Pitchfork
| Plant ||Season||Instruction|
|Anemone||Spring||Division is rarely needed, perhaps once every 8-10 years|
|Asters ||Spring||Dividing in spring allows the new plants time to establish before the end of summer|
|Bee balm ||Spring||Divide every 2-3 years in the early spring|
|Black-eyed Susan||Spring, Fall||Divide in either spring or fall|
|Catmint ||Spring, Fall||Divide every 3-4 years in either spring or early fall|
|Coneflower||Spring, Summer, Fall||Divide every 4-5 years for healthier plants; reseeds and seedlings are easy to transplant|
|Daylily||Spring, Summer, Fall||Divide every 5-7 years; it’s better to lift rebloomers in spring before they flower|
|Garden mum||Spring||Divide every 2-3 years to keep plants blooming and vigorous; discard dead central portion|
|Phlox||Spring, Summer, Fall||Divide every 3 years or when flowering diminishes; discard the woody center and plant the edge pieces|
|Goldenrod||Spring, Fall||Divide every 3-5 years to keep plants vigorous|
|Hostas||Spring, Summer, Fall||Easy to divide in early spring when foliage is emerging;|
|Sedum Autumn Joy||Spring, Summer, Fall||Easiest to divide in spring when foliage is still small; dividing clumps later won’t harm the plant but may reduce bloom for the year|
|Shasta daisy||Spring, Summer, Fall||Easiest to divide in spring when foliage is still small|
|Yarrow||Spring, Summer||Easy to divide; most types spread quickly so divide every 2-3 years|
Cut Up Rhizomes and Tubers With a Knife
|Calla lily||Spring||Most gardeners prefer to divide calla lilies in spring, especially in warm climates where you can leave the rhizome in the ground year round.|
|Dahlias||Spring||In warmer climates where the tubers remain in the ground, you can dig up, divide, and replant the tubers in early spring. If you are overwintering tubers, you can divide in the fall.|
|Irises ||Fall||Using a knife or hands, break the rhizomes apart in groups of 1-3. Cut the foliage down by half with pruners.|
|Lily-of-the-valley||Spring, Summer, Fall||Rhizomes pull apart easily; make sure each new division has a leaf and a cluster of roots|
I hope this gives you a better idea as to when the best time for dividing your perennials is, but how the plant should be divided.
It’s so important to divide your plants to keep them healthy and increase the number of blooms. It also helps to keep your garden from overcrowding.
And my favorite reason for dividing perennials? They are the gift that keeps on giving year after year. I rarely have to go to the nursery and buy new perennials because I am constantly transplanting new plants throughout the garden.
Learn more about preparing your garden for winter.
I’d love to hear from you in the comments below.
Until next time,