Planting, Dividing, & Repotting Water Garden Plants

Bare-root hardy Lilies are best planted in May and June.

• Use plastic mesh containers which are specially designed for water plants. These are ideal because they are wide, shallow, lightweight and sturdy. Most Water Lilies require large containers with a capacity to hold 1/2 – 3/4 bushels of soil per plant.
• Line the mesh basket with burlap or landscape fabric so soil can’t escape and cloud the water with particles.
• Use only aquatic potting soil. It’s very heavy without a lot of compost, peat, or sand since these materials will float.
• Fill the container half full with soil. Add 1 aquatic fertilizer tablet for each gallon of soil used in the pot.
• Place the rhizome in the pot at approximately a 45° angle. Odorata type Lily rhizomes are planted horizontally.
• Add the remaining soil to within 5 cm (a couple of inches) from the top of the tub. Water Lilies must be planted so that the crown from which the leaves grow is even with or slightly above the surface of the soil.
• Gently tamp the soil down and cover with a layer of pea gravel or other rounded stone. Be sure that no soil or gravel comes in contact with the crown. The gravel should hold the soil firmly in place which is essential when fish are present. Without the gravel, fish will disturb the soil which will result in clouded water.
• Tropical Water Lilies are best planted in June when the water temperature is around 18°C (65°F). Follow planting instructions but position the tropical rhizome almost vertically in the pot. Initially place the potted Lilies in 15-30 cm (6-12”) of water. As they begin to grow they can be gradually moved into deeper water. Water Lilies will grow successfully in 15 cm (6”) up to 90 cm (3’) of water depending on the variety. They all prefer to grow in still water away from waterfalls or jets.
• Hardy and tropical Water Lilies should be divided every 2-3 years. You’ll know it’s time to do this when you see that the leaves and blooms are smaller and fewer than usual.
• Repotting can be done anytime during the active growing season. Remove the container from the water garden to a shaded work area. Trim excess leaves 2.5 cm (1”) from the rhizome. Lift the whole plant from the pot and hose the soil off the roots. Cut the rhizome into at least 5 cm (2”) sections with one or more growing tips.
• Plant each division as per the preceding instructions with the cut end of the hardy Water Lily rhizome against the edge of the pot and the crown just above the surface of the soil and the gravel. For tropical Water Lilies plant the division vertically in the centre of the pot. In both cases, set the baskets into shallow water then return them to their normal growing depth in several weeks time.

Bare-root Lotus tubers are potted up in warm weather in round 3/4 bushel containers. This shape is preferable because a tuber can die if it becomes wedged in a corner of a square or rectangular pot.

• Plant the tuber horizontally and cover with 5 cm (2”) of aquatic soil. The growing tips must be 1 cm (1/2”) above the soil. Be careful not to break the tuber or the growing points as both are quite brittle.
• Place gravel over the top of the soil to lessen disturbance by goldfish or koi but avoid putting any near the growing points.
• Set the container in 10-15 cm (4-6”) of water. Floating leaves appear first, followed by large aerial leaves, and blooms.
• As growth becomes established, move the basket to a depth of 15-20 cm (6- 8”). If blooming doesn’t occur in the first year, you’ll certainly be rewarded the second year.
• Re-pot an established Lotus every other year. Remove the whole plant and gently hose the soil off the tubers. Divide the Lotus midway between joints and allow 2 or more joints per section. Splitting is best done before it starts to grow in early spring.

• Oxygenators can be dropped directly into the water with the metal band left on to weight them down. Most times they will root themselves in pots already there.
• Take 2-3 bunches, remove the elastic or lead weight, and push half the plant stem into the aquatic soil in a 20 cm (8”) pot.
• Leave room for at least 2.5 cm (1”) of gravel on top of the soil.
• Place these pots directly on the bottom of the pond in between the Lily and Lotus tubs.

As many oxygenators are tropical, they will need to be replaced, like an annual, every year. The exceptions are Elodea and Hornwort.

Marginal plants should be potted so that the roots are well covered with soil, leaving the crown (from which the leaves grow) protruding.

• Cover the soil with gravel and place in the water at the appropriate depth.
• Marginals that are aggressive growers should be repotted every spring. The rest can be divided every 2-3 years.
• Spring is the best time to repot with the exception of Iris. Iris should be repotted after they bloom so the flowers are not lost for that year
• To see if the aquatic is a clumping, running or horizontal grower, remove the marginal plant from its container and hose the soil off. Most Rushes form a clump like a garden perennial that can be cut into sections and set into the centre of new pots. Cattails form runners that can be cut into long sections and then curled to fit into a container. Sweet Flag, Iris, and Pickerel Rush are horizontal growers with long rhizomes that can be cut into several 7.5-12.5 cm (3-5”) pieces.
• Place the cut rhizomes in the pots with the cut end near the edge of the container and cover with 1-2.5 cm (1/2 – 1”) of gravel.