Dividing
Aquatic and marginal plants
Work from a firm edge so you do not slip into the water, wear gloves, and cover any cut, as pond mud and soil can carry tetanus and waterborne bugs; keep your tetanus cover current and wash your hands well afterwards. Note too that some invasive pond plants are illegal to spread, so never tip surplus plants or pond water into streams, ditches or the wild.
- Where to get help
- Your GP or practice nurse.
Vigorous aquatics quickly fill their baskets and crowd the pond. Dividing keeps them healthy and in bounds and gives spare plants.
When
Late spring to early summer (May to June), when plants are in active growth. Water lilies are best divided in late spring.
How
1) Lift the plant and its basket out of the pond. 2) Wash off enough soil to see the crown or rhizome. 3) For fibrous or creeping marginals such as sedges, reeds and rushes, pull apart by hand or with two forks back to back, each piece with a growing point. 4) For rhizomatous plants such as water iris, cut sections with a sharp knife, each with a bud and some young roots. 5) For water lilies, cut the rhizome into pieces with two or three growth buds each. 6) Trim old leaves and long roots, replant in aquatic baskets with heavy loam, top with washed gravel, and lower back to the correct depth.
Notes
Use aquatic compost or loam, not ordinary potting compost, which fouls the water. Check divisions for pond snails and pests before moving them.