Pond Plant Handling and Planting Instructions
When you get your pond plants, keep them cool and shaded until you are ready to put the plants away. Do not expose them to air or sunlight before you are prepared to deal with them. Water lilies and similar plants such as water fringe and water poppy will dry out quickly. If purchased bare root, it is best to pot them immediately. Otherwise, some exposed leaves and stems are likely to dry out and die, even if they are being floated in the pond. Plants which grow with their leaves out of water may need shielding from hot sun for a few days while they adjust to root loss during transplanting. Gentle mechanical sprinkling may assist during adjustment. Water lettuce and hyacinths may also need adjusting after shipping or transport by starting them in partial shade and slowly exposing them to full sun again.
Most pond plants prefer full sun once established – the more sun they get, the better they will do and the more they will bloom. In very hot climates, some varieties may benefit from partial shade.
Plants should be potted in Professional Aquatic Potting Soil. You can also use good garden soil, loam or clay. Be careful to select soil that doesn’t have much organic matter in it as this will decay causing odors and algae blooms. Definitely do not use any houseplant potting mixture, as most of the ingredients will float. Water loosens the soil considerably and many pond plants are buoyant, so pack the soil firmly around the plant. Fill to 2″ from the top of the pot. Adding 1″ of gravel or rock on top will help keep the planting media in, especially around large fish which like to dig in soil. Lower the pot into the water slowly, giving the water a chance to displace the air without disturbing the soil.
Use a 4″ to 6″ wide pot for smaller aquatics, such as water clover, fringe, or poppy. Use a 6″ to 18″ wide for arrowhead, iris, pickerel, etc. Water lilies should have as large a pot as their roots can use, eventually up to 5 gallons of soil for large plants. If any plant has insufficient roots to permeate most of the soil in a few weeks, it is better to start it off in a smaller pot and move it up in pot size as it grows, just as with a house plant. The roots aerate the soil and help prevent the growth of anaerobic bacteria, which produce toxic byproducts inhibiting plant growth. Shallow and wide containers are preferable to narrow and deep containers, giving more room for expansion. Pots without holes in the bottom are best, as they help keep soil, fertilizer, and roots inside the pot where they belong.
Most plants can be centered in their pots. If a plant has a rhizome or tuber, such as iris, pickerel, or hardy water lilies, place the back of the rhizome at the edge of the pot, and the front (the growing tip) toward the center of the pot. This allows the rhizome more room to grow horizontally across the pot.
TROPICAL WATER LILIES: Plant outdoors after the water temperature remains 65°F or more, late May or early June for most of the country. Setting the plant outdoors any earlier will shock it and delay growth. Pot into a container sized appropriately for the root system. Up to a point, the ultimate size of the plant will depend upon the size of the container, although a 2 gallon pot will grow a nice sized plant. Use soil and fertilizer as for hardy lilies, except use 2 to 3 times as much fertilizer once plants are established and in active growth. Pots may be as shallow as 3″ underwater or as deep as 18″, with around 8″ being a good average. Shallower plantings will result in faster growth due to warmer surface water. Plant tropical lilies in the center of the pot. To actively winter over, keep in a heated greenhouse. To store the tubers, wait until the plants have started to die back for the winter. Cut leaf stems and roots from tuber, and rinse well. Soak briefly in a mild fungicide solution if available, then store in clean, barely damp sand in a cool place, preferably around 40°F. Begin growth in spring in warm shallow water under good light; wait until pond has warmed up to place outside. Tropical lilies bloom profusely, far more than hardy lilies and for longer in the fall.
LOTUS: Lotus tubers are banana-like in shape. Handle carefully, as the growing tip is easily damaged. Use shallow and wide containers of 5 to 25 gallon capacity for all but dwarf varieties. Place tuber almost horizontal so that the end of the tuber is about 2 inches under the soil, and the growing tip is barely exposed. A small stone may need to be placed gently on the soil over the buoyant tuber to hold it down while rooting. Position tuber end against the pot edge and the growing tip toward the center. Place pot 2″ to 4″ under water surface. Once the lotus is growing well, it may be placed up to 12″ or even more under water. When lotus is established and growing actively, fertilize heavily, two to four times as much as for hardy water lilies. Once foliage has browned in the fall, lower pot to below freezing level. Lotus grows superbly above ground in cured whisky barrels, but do not allow the barrel to freeze solid during the winter.