Perennial splitting 101

Key Insights

• Perennial plants come back year after year with little care.
• Perennials can grow to be too large and need to have their roots split so the original plant and its offshoots can thrive.
• Splitting plants is very simple and can be done at almost any time.
• If you run out of garden space, consider gifting your perennial offshoots for others to enjoy.

One of the best parts of spring is watching all the new growth and greenery sprout up in your yard and neighborhood. If you have perennials in your landscape, you can enjoy these blooms and foliage with minimal effort.

However, if you haven’t visited your garden in a while, you might want to stop by and see if your perennial plants could benefit from splitting before the vegetation becomes unwieldy. Here’s a quick course on what plant splitting is, when you should do it and how it’s done.

Perennials are low-maintenance plants that may need to be split

Perennials are plants that are planted once and continue to grow or flower for multiple years. Perennials are great because they grow well, are sturdy against weather and disease and are a low-maintenance way to beautify your landscape (especially if you use mulch).

While there are plenty of beautiful perennial flowers, homeowners can also benefit from perennial shrubs that may add privacy and greenery with minimal effort. Because they are so low maintenance, a perennial garden is a good place to start for beginner gardeners who want to work their way up to fruit and vegetable gardening.

Here are a few perennial plants that grow well in Minnesota and northern Wisconsin (zones 3-5) you might be familiar with:

• Herbaceous perennials: Hosta, peony, geranium, rudbeckia, purple coneflower, daylily, yarrow, chrysanthemums, salvia
• Clump-forming evergreen perennials: Heuchera, salvia, phlox, fern
• Spreading shrubs: Lilac, forsythia, dogwood, hydrangea
• Underground rhizomes: Bearded iris, bugleweed, mint, aster

Sometimes, mature perennial plants can get so big that they start competing with other plants for soil nutrients and sunlight. Without adequate nutrition, these plants will start diminishing or stop flowering. Overgrown plants can reduce your curb appeal, and pruning them back or splitting the plant is an easy, cost-effective way to make your landscaping more aesthetically pleasing.

Plant splitting helps your garden thrive

Plant splitting—also known as dividing —is the act of taking the root of a mature plant and breaking it into several plants. While perennials have different root systems, the one you may be most familiar with is a bulb.

Think of a bulb of garlic–inside that bulb, there are many different cloves that are lumped together in a circular shape. It’s the same idea with bulb plants. After maturing, the bulb creates separate bulbs that can be taken off and used to start a new plant that will thrive on its own. These new plants (called offshoots) can be planted and flourish on their own.

How to know when to split your perennials

Each perennial plant is different, but on average, you should split your plants every 3-5 years (though some require splitting every year and others can go five without needing to be divided). Check with your local garden store or online resources to determine the best approach for each plant variety.

Other indicators that it’s time to split your perennials include when the plant:

• Congests the garden
• Covers more ground than usual
• Stops flowering
• Starts sprouting small shoots from the ground around the main plant stalk

When you split your perennials

Splitting can truly be done any time of year as long as the plants are well-watered after replanting. However, they tend to do best when they’re dormant, either in the late fall before the cold sets in or in early spring when they’re just showing signs of new life. The exception to this is spring-flowering perennials, which are best divided in the summer once they’ve started to fade. Again, your local gardening center or the University of Minnesota Extension are great resources for determining the best time of year to split your plants.

How to split your perennials

Splitting is very easy! Here are a few quick steps to successfully divide your plants.

1. Dig up the plant. Use a shovel, trowel, or garden fork to dig up the entire plant (note that plants may have spread out or grown deeper than where you planted them, so be safe and dig a few inches around the stalk). Always call 811 before you dig to ensure underground utility lines can be marked.
2. Carefully separate the bulbs, clumps, or roots. Brush off dirt and gently divide the plant. Depending on the plant, you may need a knife to separate the pieces, but many species can be gently divided by hand.
3. Remove any dead bulbs. Toss bulbs or sections that are shriveled, soggy, or damaged.
4. Replant the original parent plant and offshoots. Put the original plant back where it was (unless the parent bulb has died), and plant the offshoots at the same depth and distance recommended for the plant. Add some compost or nutrient-rich soil to the plants to give them a healthy boost.

Note that some plants can’t be replanted right away and may need to be dried out before replanting. Check online or with your garden center for your specific plants to give them their best shot at flourishing.

5. Water and watch. Water the new plants well for a few weeks until you start to see new growth. Then, water on a regular schedule. Note that it may take a few years for the new plants to grow and flower at the same rate as the original plant.

If you don’t have any more space in your garden for your new offshoots, consider:

• Planting offshoots in pots. Since it may take a year or two to grow and start flowering, putting the new plants in a pot is a good option to get them healthy.
• Gifting them to friends, family and neighbors. Just like fruits, vegetables and even dough starters, your extra perennials can make great gifts and ensure that nothing is going to waste.
• Donating them to your garden center, club, or local organization. If you run out of people in need of plants, call up local establishments or gardening centers and clubs to see if they’d like your offshoots.

Enjoy your garden

Splitting plants is easy to add to your spring lawn care routine. Gardening has great physical, mental and emotional benefits that help you stay healthy. Plus, having native plants or a pollinator garden helps the local ecosystem and planet while bringing beautiful butterflies and birds to your front door!

Having an eye-catching outdoor space adds value to your home's curb appeal, too. If you’d like advice on what kind of perennial plants would help maximize your yard, reach out to an Edina Realty agent today.