How do I take care of my Hardy plants in the winter?
Most hardy bog plants can be trimmed to about 3-6” after October 15th in most Northern states and placed in the deep section of the water garden. Aquatic grasses, reeds, cattails, rushes and similar grass-like plants should be only trimmed back to about 18 ” and remain in shallow water (1-6” of water above pot) so that their stems rise above the surface of the water. These plants “breathe” through their stems in the winter. Water iris should not be moved to deep water since they can suffocate in water more than a couple inches above the pot. Oxygenators and water lilies can stay in the deep section (18-36”) of the pond they normally grow in through the summer. As long as they are below ice level (maximum ice depth is 8-10” in Ohio), they should over-winter fine. Trim all remaining leaves and stems off your lilies after the first couple freezes to prevent them from fouling the water as they are shed.
Why aren't my water lilies blooming?
There are several possible reasons that your water lilies are not blooming. Are your lilies getting enough sun? Most water lily varieties require at least 5 - 6 hours of direct sun to bloom (however there are some varieties that will flourish in 3- 4 hours of direct sun ). Water lilies should be fertilized regularly during the growing season; we recommend fertilizing every three weeks with one aquatic plant tab per gallon of soil. We do carry a once-a-year fertilizer as well. Water lilies will bloom infrequently if pot bound. It is best to pot your lilies in a 5 gallon or larger container so that you will not have to divide every year. Most lilies can grow for 2 - 3 years in a 5 gallon container before needing to be repotted.
When can I add aquatic plants?
You can add water 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 need warmer water temperatures of at least 65 degrees minimum.
Water Lilies and other Aquatic Plants
The floating leaves of the water lily provide cover for fish and protection from the sun. To keep lilies healthy and enhance their elegance, submerge them at a depth of about 18 - 24 inches in the calmer areas of the pond; they do not like turbulent, moving water from a waterfall or fountain, for example.
Oxygenating Plants are submerged plants that provide some 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. No planting in pots or baskets is required; they are tied in bunches usually with a lead weight, and all you need to do is submerge them in the bottom of your pond. Common types of oxygenating plants include: Anacharis, Cabomba, Hornwort, and Parrot’s Feather.
Marginal Plants are attractive hardy plants that 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. Examples include: Lotus, Papyrus, Taro, Water Iris, Arrowhead, Lizard’s Tail, Elephant Ears, Marsh Marigold, Pickeral Rush and Cattails.
Floating plants are another important group of aquatics and common examples include the water hyacinth and water lettuce. They do not need soil but simply float on the water’s surface and they can multiply quickly. They are popular water plants because they are economical and grow easily. Some states have banned them because they overwinter and can clog waterways especially in the South.
Can I put tropical lilies in my pond?
Yes, however tropical water 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. They are worth the cost and effort because they are extremely beautiful, are prolific bloomers and provide a wide array of flower colors, even blues and purples that hardy lilies don’t offer.
If you don’t want a tropical water lily then there are plenty of hardy water lilies to choose from that can over-winter in your pond and come back year after year.
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.
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. 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. Regarding Water Hyacinths: One water hyacinth floating on the pond surface can become twenty+, 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.
How should I fertilize my plants?
Potted plants such as water lilies can benefit greatly from being regularly fertilized with tablets. 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 from special fertilizer such as Throw-Tabs.
What type of containers should I use for water 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. Black Plastic pots or mesh baskets - two good choices for plants. Fabric planters - 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. Fabric planters 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.
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. We have a spray called Aphid X that is effective also.
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 a minimum of five to six hours of sunlight a day. Water gardens in shady areas can be lovely but choose shade-tolerant water plants and realize that blooms will be minimized or even non-existent.