Plant Care

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Stocking

Plants beautify a pond while aiding pond health. Aquatic plants help reduce pond algae and evaporation, stabilize water temperature and create a food source and shaded refuge for fish. Plants can be stocked as desired with the following constraints if fish are present: 1) Cover no more than 60 % - 75 % of the pond surface with plants; 2) Too many floating plant leaves, such as lily pads, can prevent good oxygenation; 3) When fish are present, stock no more than approximately one oxygenating plant per 400 gallons of pond water. Oxygenators produce oxygen during the day, but consume it again at night. This can suffocate fish.

Placement

Since aquatic plants thrive in varying depths of water, create a series of steps or shelves around the pond so that planting baskets can be placed at the appropriate depth. Cinder blocks or upside down pots can be used to elevate plants to the appropriate level if shelves are not present. Marginal/Bog Plants: Place from moist soil 6” - 20” inches from the top of the pot (depending on the plant species). Oxygenators: Submerge below water level, up to three feet deep. Lilies: From 18” to 36” below water level. If placed deeper they will grow, but not as vigorously. Clay bottom ponds or ponds with contained bog or planting areas can have plants placed directly in the soil. If plants are desired on a non-contained shelf or on the pond bottom, an aquatic pot should always be used to control plant growth. This will maintain a clean pond free from debris at the bottom (See the illustration for examples of contained planting shelves.).

Soil

Aquatic planting soil is designed for safe use with fish and to minimize floating debris and algae proliferation. To mix your own soil use clay rich soil, sand and cow manure. Be certain that the soil has not been compromised with pesticide or other toxins. Store bought terrestrial potting soil contains too much fertilizer and can be harmful to fish. Add no more than 1 part aged cow manure (three or more years old) to 5 parts soil. Avoid steer and chicken manure. Cover the top of the soil mixture with small rocks or gravel.

Dividing & Replanting

Marginal plants get root-bound and must be divided from time to time. If plants are being fertilized, they usually require division every two years. In order to remove the plant and root-ball intact, use a knife to cut the side of the plant pot open. Slice through the root-ball, cutting the plant in half. Depending on the size of the plant, it can be divided further. Make sure all marginal plants have at least five to ten root stalks per division. Re-pot with a garden soil mix or aquatic mix (see above), and make sure that the plant is at the same soil depth as it was before division. Water thoroughly. The surface area can be covered with washed pebbles or gravel. Replace the plant into the pond at the same water depth it was sitting at before.

Overcrowded plants benefit from division and replanting in spring and in fall. Divide lilies in the spring. Remove the lily crown from the container and gently hose it to remove dirt. The lily crown will consist of a stout main rootstock and smaller roots branching from the sides. Cut the smaller roots where they join the main root. Remove brown, limp roots and, if necessary, trim the healthy white roots to fit in the container. Keep roots moist while planting. Fill container about 1/3 full. Push fertilizing tablets into soil. Fill container further till about 1/2 full. Create a shallow ‘well’ in the soil in the center for tropical lilies and to the side for hardy lilies. Water the soil thoroughly. Tropical water lilies can be placed in the center of the container, spreading the roots around the plant. Hardy water lilies must be placed against the side of the container, at a 45-degree angle, so that the growing tip faces the opposite side of the container. Gently cover the tuber or rhizome and roots with soil. Take care not to bury the crown of the lily. Press the soil firmly and saturate thoroughly with water. Cover soil with about 1/2 inch of washed pea gravel, again keeping the crown of the lily above the gravel. Lower newly potted lily into pond to a depth of 6 - 18 inches. Lilies require 2 to 3 weeks of adjustment after planting before new growth will resume. Water lilies are heavy feeders. Feed the lilies once a month with aquatic fertilizer during the growing season.

Copyright 2001