Autumn and winter are perfect for tending to your perennials, ensuring they are well-prepared for the next growing season. Dividing and propagating perennials during this time can help your plants thrive, improve their health, and provide you with more plants for the garden.

Perennial Definition

A perennial is a plant that lives for more than two years and typically flowers in spring and summer. Many evergreens are also considered perennials, but they often go dormant in the colder months and come back to life when the weather warms up.

Cleaning Up

Cleaning up your perennials in autumn helps tidy your garden and prepare the plants for dormancy. Remove dead or damaged foliage, leaving about 5 cm of the plant's stem. This will:

• Prevent water from sitting in the crown, which can lead to rotting.
• Allow buds on stems to continue growing by leaving some height to the plant.

If your plants show signs of disease, pruning them in cooler months can help prevent the spread of disease to the next growing season.

Mulch

Mulch helps protect perennials by maintaining a consistent soil temperature, reducing stress, and preventing weeds. Apply mulch around your plants but be sure not to cover the crown of the plant, as this can cause rot. Materials like pea straw and bark mulch are ideal for this purpose.

Watering

Even though perennials are more dormant in the cooler months, they still need water. If rainfall is insufficient, or if your plants are growing under trees that block rain, give them a generous drink at least once a month.

Dividing Perennials:

Over time, perennials naturally expand into large clumps. If you notice a plant’s growth has slowed, or the centre of the clump is browning or collapsing, it may be time to divide it. Dividing perennials encourages new growth and can also help revitalise older plants.

Tips for Dividing

• Timing: Though you can divide perennials at any time of year, autumn and winter offer cooler conditions, allowing the roots to settle and prepare for the warmer months ahead.
• Tools: For delicate plants, use a hand fork or sharp knife, and spades or handsaws for larger perennials.

Transplanting

When transplanting divided perennials, begin by lifting the plant carefully. Use the plant's drip line as a guide to ensure you're taking the essential roots. If you’re replanting in the garden, enrich the soil with compost and Oderings Garden Replenish. For pots, use Oderings Potting & Basket Mix, which contains a balance of fertilisers for healthy root development. Keep newly transplanted plants well-watered; if potting them, place them in a glasshouse or propagation house for accelerated growth.

Root Types and Division Methods

Offsets: Small plants that grow at the base of the parent plant. They can be separated using a trowel or hand, ensuring the new plant has sufficient roots. Examples: Echinacea, Agapanthus, Lamb’s Ear, Hostas.

Surface Roots: These roots grow just beneath the soil and can be divided by digging between the mother plant and the new plant. Examples: Sedum, Veronica, Ajuga, Violas.

Taproots: A large central root that can be sliced into smaller plants with a sharp knife, ensuring each division has side shoots and part of the main root. Examples: Euphorbia, Platycodon, Dicentra.

Underground Running Roots: These roots form suckers just under the surface. You can dig out a section of the plant while leaving the parent plant intact. Examples: Anemone, Geraniums.

Woody Roots: These roots form when the stems of the plant rest on the soil and develop roots. You can cut between the rooted stem and the parent plant to create a new division. Examples: Iberis, Lavender, Penstemons, Buxus, Thyme.

Garden Expert Tip

Dividing perennials during their dormant period gives them time to establish new roots before the growing season, ensuring healthy plants that thrive in the spring and summer. For best results, always choose a variety of perennials that suit your garden’s climate and soil conditions.