Watercress is a hardy plant and generally grows well in winter temperatures between minus 25 to minus 30 degrees Fahrenheit. Watercress bought in a grocery store don’t usually have roots, but place it in a aerated pond (pond utilizing a pump) secured with rocks or in a barrel of water and it will root quickly.
Watercress with Roots
Watercress that does root spreads by sending out runners of about 4 inches from their roots through the water. In early spring, watercress sprouts small, white flowers and grows best in shallow and medium to fast running water. Anchor the plant in a pond with gravel and small stones. The yard pond must be aerated as watercress and other running water plants won’t do well in stagnant water. Watercress will use up valuable nutrients from the water if anchored in soil or sand. As an added incentive to growing watercress, it’s great to eat.
Once the watercress begins to send runners out and matures, cut back the older plant to allow for more growth. Harvest watercress by cutting the plant just above the ground ensuring to leave the roots in order to provide for another crop for the following year.
Water Lettuce for the Pond
Water lettuce does not root and floats freely on the surface of running water. Water lettuce is an aggressive plant producing wide leaves in a circle around a head that from the top resembles a rosette shape but from the sides, resembles a loose head of lettuce. It often reaches 6 inches in diameter.
Toss water lettuce, green side up into the yard pond. Water lettuce grows best in partial shade. Full sun will fade the green color of the plant. Frost destroys the plant and its best to rake the lettuce out of the pond before it rots.
The Unusual Parrot’s Feather Plant
The parrot’s feather plant grows either submerged in a pond or other water areas or outside the pond. Parrot’s feather stems grow up to 60 inches tall, and have textured foliage resembling pine needles. The plant also uses the same nutrients that algae depend on, so the plant is an excellent algae-deterrent, but in a aerated pond, it provides nutrients for fish when spawning. It also provides shade and shelter for fish.
If there is a waterfall feature in the yard, grow parrot’s feather in waterfall crevices or around pond edges. Parrot’s feather is sensitive to frost, but it preserves well under ice in frozen yard ponds. Several states consider parrot’s feather a noxious weed. It is banned in the states of Washington, New Hampshire, Alabama, Vermont, Connecticut, Maine and Wisconsin.
Always check with your state’s laws regarding shipping rules of plants.