The Ideal Time to Divide Perennials for Healthier Growth, According to Experts

Perennials are a beautiful addition to any garden, bringing vibrant blooms that return season after season. If you want your perennials to thrive and multiply, dividing them can lead to healthier growth and more flowers. Experts agree that the timing and method of dividing are key to the plant’s success, helping it to establish deeper roots and absorb more nutrients from the soil.

When to Divide Perennials for Maximum Growth

According to Tammy Sons, founder and CEO of TN Nursery, the ideal time to divide your perennials is during the spring and fall seasons, particularly in the early part of these seasons. This timing helps minimize stress on the plants and gives them a chance to establish new roots before extreme temperatures set in. However, the best time to divide can vary depending on the species. “Plants like daylilies and hostas do best when divided in early spring, while irises benefit from division in late summer,” says Sons.

In general, it’s advised to divide perennials when they are not in bloom. Lorraine Ballato, horticulturist at the New York Botanical Garden, explains, “Dividing a plant during its flowering period can disrupt its ability to produce flowers. For instance, peonies should be divided in the fall after their flowering period, as they recover and re-energize during this time.”

Tips for Dividing Perennials

Here are expert tips to ensure your perennial division is done with minimal stress:

1. Check for Overcrowding: Look for signs such as fewer blooms, dead spots, or plants spreading into unwanted areas. If overcrowding is apparent, it’s time to divide.
2. Completely Dig Up the Plant: According to Laura Janney, CEO of the Inspired Garden, the easiest method for dividing is to dig up the plant entirely. “Shake off the excess soil and remove any dead parts,” she advises. For larger plants, use a sharp spade to cut them in half, ensuring a clean slice. Smaller plants can be divided with a knife, trimming excess roots.
3. Use Sharp Tools: Always use sharp tools like a spade or garden fork to divide perennials. This helps preserve the root system of each section, ensuring they have the best chance to thrive, says Tammy Sons.
4. Keep Divided Sections Moist and Shaded: After dividing, place the sections in a shaded area and water them thoroughly. This helps minimize transplant shock, according to Sons.
5. Ensure Plant Health Before Dividing: Never divide a plant when it is stressed. Janney recommends watering the plant well a few days before dividing to ensure it is in good health.
6. Avoid Dividing Blooming Plants: It’s crucial not to divide perennials that are blooming, as they need more resources to support their flowers. Focus on dividing those that are not in bloom for optimal resilience.

By following these expert tips and understanding the best time to divide, your perennials will flourish, producing more blooms and healthier growth for seasons to come.