Tip from the test garden

Basic gardening guide

Clumping perennials in containers – such as agapanthus – can become crowded.

Step 1: Gently ease the plant out of its container.

Step 2: Using a sharp tool, slice the plant into roughly equal sections, each with roots attached. Keep healthy sections only; discard the rest.

Step 3: Replant each section with fresh potting soil in its own container.