Plant division is an excellent way to propagate your favorite clumping houseplants and outdoor perennials, creating multiple new plants from a single mature specimen. This process involves carefully separating a plant's root ball into smaller sections, each capable of growing into an independent plant. It's not only a fantastic way to expand your plant collection but also helps to rejuvenate overgrown plants, promoting healthier and more vigorous growth.
Why should I divide my plants?
Dividing your plants offers several benefits, from improving plant health to simply getting more plants for free! Over time, many clumping plants become dense and crowded, leading to reduced flowering or growth, and sometimes even a decline in overall health as roots compete for resources. Division alleviates this congestion, giving each new section room to thrive.
Here are the main reasons plant owners choose to divide their plants:
Propagation: The most obvious reason is to create new plants! Dividing a mature plant can yield several smaller ones, which you can keep, share, or replant elsewhere.
Rejuvenation: Overcrowded plants can become less vigorous, produce fewer flowers, or even start to die out in the center. Dividing them revitalizes the plant by promoting new growth and better air circulation around the crowns.
Controlling Size: For plants that spread quickly or become too large for their space, division is a natural way to manage their size and keep them contained.
Improving Health: It's an opportunity to inspect roots for any signs of disease or pest issues and remove them before replanting healthy sections.
When is the best time to divide plants?
The ideal time for plant division varies depending on the type of plant, but a general rule is to divide when the plant is not actively growing or flowering, minimizing stress. For outdoor perennials, this usually means early spring or fall, while many houseplants can be divided almost any time of year.
When should I divide outdoor perennials?
For most outdoor perennials like Hostas (Hosta spp.), Daylilies (Hemerocallis spp.), and ornamental grasses, early spring as new growth emerges, or early fall after flowering, is best. Dividing in spring allows the new divisions to establish roots before the heat of summer, while fall division gives them time to settle before winter dormancy. Avoid dividing during the peak of summer heat or when plants are actively flowering, as this can severely stress them.
When should I divide houseplants?
Many clumping houseplants, such as Snake Plants (Sansevieria trifasciata), Peace Lilies (Spathiphyllum wallisii), and Ferns, can be divided any time of year, but they will establish fastest during their active growing season, typically spring or early summer. Avoid dividing when the plant is flowering, as this redirects energy from root establishment. It's also a good practice to repot and divide your houseplants every 1-2 years or when they become root-bound.
How do I divide my clumping plants?
Dividing a plant might seem daunting, but it's a straightforward process that becomes easier with practice. Always start with clean, sharp tools to make clean cuts and prevent disease transmission. Here's how Planta recommends you divide your clumping plants:
Prepare Your Tools and Workspace: Gather a sharp knife, a clean trowel or spade, a sturdy tarp or old sheet (for outdoor plants), and new pots with fresh potting mix if you're repotting immediately. Sterilize your cutting tools with rubbing alcohol or a 10% bleach solution.
Dig or Remove the Plant: For outdoor perennials, carefully dig a wide circle around the plant's base, at least 15-30 cm (6-12 inches) away from the crown, to avoid damaging the roots. Gently lift the entire root ball. For houseplants, carefully slide the plant out of its pot, tipping it on its side if necessary.
Loosen the Soil and Inspect Roots: Gently shake off excess soil from the root ball so you can clearly see the root structure. This helps you identify natural divisions. You may need to gently tease apart roots with your hands.
Divide the Root Ball: Depending on the plant, you can divide it by hand or with a tool. Many clumping plants like Hostas can be pulled apart into natural sections with your hands. For denser or tougher root systems, use a sharp knife (for houseplants) or a sharp spade/axe (for tough outdoor perennials) to cut through the crown and roots. Ensure each division has a healthy clump of roots and at least one growing point (foliage or buds).
Trim and Replant: Trim any dead, damaged, or overly long roots from your divisions. You can also trim back some of the foliage to reduce water loss, especially for larger divisions. Replant your new divisions immediately into their prepared spots in the garden or into new pots with fresh, well-draining potting mix. Ensure the crown of the plant is at the same level as it was before, or slightly higher for some plants.
What care do new divisions need?
After division, your new plants will need a little extra TLC to help them establish successfully. They are essentially recovering from minor surgery, so providing the right conditions is key to their survival and future growth.
Water Immediately: Thoroughly water your newly planted divisions right after planting. This helps settle the soil around the roots and provides essential hydration.
Provide Partial Shade: For the first few weeks, place newly divided houseplants in a slightly shadier spot than usual, or provide temporary shade for outdoor divisions, especially if they are exposed to intense afternoon sun. This reduces stress while the roots are establishing.
Monitor Moisture: Keep the soil consistently moist but not waterlogged. Check the soil moisture regularly, and water when the top 2-3 cm (1 inch) of soil feels dry. Remember, newly established plants have a smaller root system and may dry out faster than a mature plant.
Avoid Fertilizing: Refrain from fertilizing immediately after division. Wait until you see signs of new growth, usually a few weeks, before resuming a regular fertilization schedule. This allows the roots to focus on establishment without being forced to take up nutrients they're not ready for.
Be Patient: It can take several weeks for new divisions to show significant new growth as they prioritize root development. Don't be discouraged if they look a bit sluggish initially.
Dividing your plants is a rewarding gardening task that helps maintain their health and multiplies your green collection. By following these simple steps, you can confidently divide your favorite plants and enjoy their beauty for years to come.