Frequently Asked Pond Plant Care Questions

Q. When can I add plants?
You can add plants anytime in the spring, summer or fall. In the spring, be sure to wait until the last frost date in your area before adding hyacinths and tropical lilies. These plants do poorly in lower water and air temperatures.

Q. What types of plants should I use?
There are many fine choices of aquatic plants to choose from. Here is a short list of possibilities. Check with your local aquatic plant dealer for more choices.

Water Lilies

The lush, floating leaves of the vibrant lily sweep across the pond’s surface, providing cover for fish and protection from the sun. To keep lilies healthy and enhance their elegance, submerge them at a depth of 18 inches.

Other types of pond plants include: Lotus, Papyrus, Taro, Iris, Water Hyacinths, Dragon’s Tail, Elephant Ears, Canna Lilies and Cattails.

Oxygenating Plants

These submerged plants provide essential oxygen and act as a natural biological filter, benefiting the entire pond ecosystem. One bundle of oxygenators is recommended for every square foot of pond surface. Most garden centers and retailers carry a few varieties, usually in tubs in the plant section or near the fish livestock. No planting in pots or baskets is required; they are tied in bunches around a metal weight, and all you need to do is submerge them in the bottom of your pond.

Common types of oxygenating plants include: Anacharis, Cabomba, Hornwart, Water Wisteria, Baby Tears and Parrot’s Feather.

Marginal Plants

These attractive hardy plants come in myriad sizes, shapes and colors. They soften the edges of the pond and help the pond blend naturally into the landscape. These plants benefit the pond by removing excess nutrients that could otherwise feed algae. Marginal plants grow best in shallow water and should be submerged to a depth of 10 inches or less. 

Common types of oxygenating plants include: Green Acorus, Sweet Flag, Canna, Sedge, Taro, Palm, Umbrella grass and Rush.

Q. Can I put tropical lilies in my pond?
Yes, however, tropical plants and lilies are not winter-hardy. They will die in the winter if left outdoors and will not return next spring. Tropical lilies can be brought indoors during the winter or replaced every year.

There are plenty of hardy water lilies to choose from that can over-winter in your pond and come back year after year.

Q. What should I do with my plants in the winter?
Most aquatic plants (with the exception of tropical lilies and water hyacinths) can be left in the pond through the winter. Trim back all dead foliage, then submerge the plants in the bottom or deeper section of the pond to prevent the plants from freezing. Hardy water garden plants will come back year after year.

Q. How do I keep my plants from overtaking my pond?
Be conscious of the nature of the plants you are adding to your pond. Some plants, such as cattails, will send out roots and spread throughout the pond, and it can be quite difficult to contain their growth. You may want to avoid certain species.

Some plants are illegal for sale in certain states due to the concern of these plants being introduced into natural waterways and thus disrupting the natural balance. Reputable aquatic plant dealers will not sell plants that are not legal in your area.

Containing root growth: By using plastic containers or fabric planters, such as TetraPond® AquaPlanters, plants will have a more difficult time spreading their roots. 

By avoiding the temptation of lining the bottom of the pond with gravel or rocks, you are deterring the spread of root growth that can become matted into the stone bottom. Water gardening, just as your terrestrial garden, requires some maintenance in thinning out unwanted plant growth.

Water Hyacinths: One water hyacinth floating on the pond surface can become hundreds, quickly overtaking a pond during the summer. Consider placing fishing line across the water surface to help ‘corral’ and contain these floating plants into a corner or section of the pond.

You may also want to confine your water hyacinths to a “header” pond – the smaller pond that feeds the waterfall – and keep it out of the larger, primary pond.

Q. How should I fertilize my plants?
Potted plants such as water lilies can benefit greatly from being regularly fertilized with tablets. TetraPond® LilyGro™ Tablets can be inserted into the planting media to fertilize the roots, leading to healthier plants and stronger blooms.

Floating plants that absorb nutrients directly from the water through their roots, such as water hyacinths, can benefit greatly from TetraPond® FloraFin liquid fertilizer. This fertilizer is poured directly into the pond and does not encourage algae growth.

Q. What type of containers should I use for plants?
Containers are useful for plants like water lilies, lotus and marginal plants. They’ll help keep roots from spreading and allow you to rearrange your plants and change the look of your pond easily.

Plastic pots or mesh baskets – two good choices for plants.

Fabric planters - AquaPlanters are very versatile products that allow you to place plants such as lilies on the bottom of the pond or into tight corners, and marginal plants between rocks. They can even be used outside the ponds. AquaPlanters allow water and nutrients to reach the roots, while containing the root spread.

Forming fabric planting beds - You may use landscape fabric or scrap pond fabric under-liner to form “pockets” between rocks on the planting shelves. These areas can be filled with planting media and planted with marginal plants.

Q. How can I control aphids?
Avoid flowering trees overhanging the pond, as aphids are attracted to them and can fall off into the pond. Avoid placing already infested plants in the pond. A light spray of vegetable oil can be used to smother insects but will leave an oil film on the water surface, which is highly undesirable. Spraying with a garden hose will wash insects into the pond and the fish can then help by eating them, as they love an insect snack.

Q. Do I need a sunny location for my pond plants to do well?
Sunlight is essential for healthy plant life, but too much can lead to an overabundance of algae and unattractive green water. Typically, the best location for a water garden is one that receives five to six hours of sunlight a day.