Wintering Water Plants, Fish and Ponds
 One of the fastest growing segments of the gardening world is water gardening. More and more people are discovering the magical quality that water brings to the landscape. Because we live in a cold northern climate, there are steps to be taken to insure that plants, fish and ponds winter successfully. After taking these simple steps, most people allow their water feature to winter naturally. A few gardeners invest in stock-tank heaters to keep some of the water from freezing. While this is an option that allows you to leave many of the plants and fish in the pond, it uses a tremendous amount of energy and if the power source fails, the plants and fish may be killed anyway. If you are going to try a heater, make sure it is anchored so that it cannot possibly come near the edges of the pool liner. And even with an in-pond water heater, plants that are truly tropical will have to be removed (tropical lilies, umbrella palm, taro, etc.)
.Water Plants
There is such a variety of truly wonderful plants that can be used in and around garden ponds that what to do with them over winter can be confusing. The first and most important step to wintering water plants successfully is to be sure you have them identified correctly. Gardeners commonly use a combination of hardy and non-hardy plants to enhance their water feature and each has different winter care needs. If you aren't sure about the exact identity of the plants you have, come in and ask us. For winter care purposes, plants can be classified as either non-hardy floating/ submerged plants, hardy bog/marginal plants, hardy water lilies, non-hardy water lilies and other non-hardy bog/marginal plants. To create a specific feeling or look near a water feature, gardeners often use plants that are usually grown as indoor plants in our area. For example, you might use an elephant ear plant to provide the bold, tropical look. Those plants should be wintered as you would any other tropical plant.
In addition to specific variety, other factors will influence success in over-wintering water plants. First, when a plant is hardy the directions may say to cut the plant back and drop the pot into the deepest part of the water for the winter. This only works if your pond is at least 18 inches deep (and it's much more reliable if the water is much deeper). If it is less than 18 inches deep, some of the hardiest plants might survive, but others will be killed. If there is any question, just bury the root system in the ground several inches below the surface and mulch it heavily just before the ground freezes. The following spring the plant can be dug up and repotted before putting it back in the pond. Another factor that will influence winter survivability is how well the plants are acclimated to the weather before winter sets in. Plants that have been growing in the immediate area for several weeks before fall weather sends them into dormancy have a much better chance of surviving than those planted after fall begins, especially if they were brought in from a warmer climate. Plants need some time to relax and get ready for winter, so it is important to discourage any new growth in late August and September. Don't fertilize beyond early August. Following the recommended steps to prepare the plants for winter at the recommended times is important.
Storing Hardy Bog/Shallow Plants: These are the easiest water plants to over-winter. They can stay in the pond all year. As the weather begins to cool, the foliage will begin to yellow or brown. This may happen before or after a killing frost. When it happens, simply trim off all the foliage leaving inch or two above the soil level. Hardy bog/shallow plants can be dropped to the bottom of the pond in their original containers where they will spend their winter until the water begins to warm up in spring. With cattails, be sure to leave their old, dry foliage attached until spring. It acts like a snorkle, supplying the root system with oxygen.
Storing Hardy Water Lilies: All of the water lilies Bachman's sells are considered winter hardy in Zone 4. Unless your water feature is deep enough that you are absolutely sure it won't freeze solid to the bottom, you will need to winter the hardy water lilies indoors. In late September and early October, the lilies will stop growing and the leaves will go yellow or brown. At this point, pull the container from the water and remove all the foliage. The root system can be stored either in the soil or bare root. Either way, they will have to be stored where it stays very cool but won't freeze, such as a cold area of the basement or a refrigerator. The area also should be dark. Stored lilies must be kept damp. If you are storing them in their pot with their soil, try putting the pot into a dishpan. You don't need to keep the pan full of water, but you can keep the soil consistently moist. If you don't have enough space to winter the lilies in their container, you can winter them bare root. Take them out of their pots and rinse off the root system. They can then be packed into a container full of damp (not wet) sand and stored in the dark like you would potted water lilies. Ideally, dormant water lilies should be stored cool enough that they don't try to start growing during the winter. Allowing them to sprout while in storage will just sap their strength.
Storing Non-Hardy Water Lilies: Successfully over-wintering non-hardy water lilies is a challenge. In nature, growing in consistently warm climates, they don't ever go fully dormant. Many gardeners grow and enjoy tropical lilies throughout the season and then treat them as annuals. If you follow the same steps as storing a hardy lily bare root, you will have about a 50/50 chance of success. If you want to try storing plants in a large aquarium, you will need 75-80º and strong light 12-18 hours each day. The biggest impediment to overwintering tropical water lilies is that they cannot go back into the water outdoors until the water temperature is at least 65º. In Minnesota, that doesn't leave enough time for the plant to grow and bloom before it gets cold again.
Storing Non-Hardy Bog/Shallow Plants: There are several plants in this category that make very nice indoor plants for the winter. Papyrus, umbrella plant and taro can be kept actively growing in a sunny window. While they don't have to be submerged in water, they should be placed in a saucer that will hold some water. Water cannas can be stored bare root just like you would any Canna, or stored potted and dormant in a cool basement or refrigerator. Elephant ears can be saved like bulbs, cool and dry in peat moss
Storing Floating and Submerged Plants: Most free-floating and submerged plants are extremely tender. They are also fairly difficult to winter indoors, so they are usually considered annuals and replaced each season. To try to winter floating or submerged plants, place them in an aquarium with a light. If you are working with water hyacinths, leave the aquarium only partially filled so they will have space for their leaves to gather light. Remember not to put them back out until the water is warm (65-70º) in the spring.
Winter Care for Surrounding Plantings
Most water features are surrounded by plants that are directly planted in the soil.
Some of those will be bog lovers that grow where water overflows from the pond.
Unless you have intentionally planted tender plants, everything should be hardy and can winter where planted. A few of the plants commonly used at water's edge are ferns, cardinal flower, marsh marigold, Ligularia, cattails and horsetail. Lots of other perennials and moisture-loving shrubs are used near water features and they are all wintered as you would any other perennial or shrub.
Wintering Ornamental Fish
Unless you are going to keep the water open all winter with a heater, ornamental fish such as Koi and goldfish should be overwintered indoors. If they are small, fish can be kept in a properly equipped aquarium. For large fish (or too many small fish), you can set up a small stock tank or garbage can in the basement. Be sure to use a circulating pump to aerate the water. When fish are kept cool indoors, they won't need to be fed very often. If they are kept cold (below 55º) they shouldn't be fed at all because their digestive system shuts down and the food might poison them. Koi and goldfish are tolerant of cool water but can be killed by excessive chlorine or other water additives. Catching the fish can be a challenge. If possible, remove all the plants and drain most of the water from the pond first (the water is great for potted plants). Fill a clean bucket with some of the pond water and transfer the fish with a net. If the fish are kept in the bucket too long, they may begin to surface and gasp for air. Transfer them to their winter home as soon as you can or aerate the water in the bucket. For more help with over-wintering fish indoors, ask at your local pet store.
Winter care of the pond
All water features that do not have a natural soil bottom will need cleaning each season and this can be done in fall or very early spring. To do this, drain as much of the water as possible. This can be done by attaching a short length of garden hose to a circulating pump or it can be bailed out with a bucket. Scrub the sides of the pond with a soft brush and rinse the pond before refilling. Whether or not the pond should be left filled with water will depend of the type of pond structure. If it has a rigid fiberglass liner it should be left filled. Floating a large block of styrofoam in the water will keep ice from pushing out the sides. When left empty, a rigid liner can be lifted out of its place as the ground underneath freezes and expands - and resetting it in the spring is very difficult. Flexible liners can be left filled or drained. Concrete ponds should be drained, dried and tarped to keep water from accumulating.
| Non-Hardy Water Lilies* |
Afterglow |
Blue Beauty |
Blue Triumph |
Bob Trickett |
Charles Thomas |
Colorata |
Dauben |
Delicatissma |
Director G. T. Moore |
Enchantment |
Evelyn Randig |
General Pershing |
H.C. Haarstick |
Leopardess |
Marian Strawn |
Margaret Mary |
Mrs. George Pring |
Panama Pacific |
Pink Perfection |
Pink Platter |
Red Flare |
Saint Louis |
Shirley Bryne |
White Delight |
Wood's Blue Goddess |
Yellow Dazzler |
Hardy Water Lilies* |
Aflame |
Attraction |
Charlene Strawn |
Chromatella |
Comanche |
Conqueror |
Fabiola |
Firecrest |
Froebeli |
Gladstone |
James Brydon |
Joey Tomocik |
Hollandia |
Marliac Albida |
Marliac Rosea |
Pink Beauty |
Pink Sensation |
Rembrandt |
Rose Arey |
Rosy Morn |
Sioux |
Sirius |
Sulphurea |
Texas Dawn |
Venus |
Virginalis |
*There are many hundreds of varieties of water lilies. We have listed some of those commonly sold in our area. If the variety you have is not on either list, let us know and we will try to help determine if it is hardy or not.
| Hardy Bog/Marginal Plants |
Pickerel Rush Pontederia |
Zebra Rush Scirpus |
Corkscrew Rush Juncus |
Flowering Rush Butomus |
Arrowhead Sagittaria |
Bogbean Menyanthes |
Sweet Flag Acorus |
Horsetail Equisetum |
Cattail Typha |
Hornwort Ceratophyllum |
Lizard's Tail Saururus |
Parrot Feather Myriophyllum |
Pennywort Hydrocotyle |
Primrose Creeper Ludwigia |
Water Clover Marsiela |
Blue Water Iris Iris versicolor |
Yellow Water Iris Iris pseudacorus |
Variegated Flag Iris pseudoacorus 'Variegata' |
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Non-Hardy Bog/Marginal Plants Treated as Annuals: Frogbit Limnobium
Non-Hardy Plants to Winter Indoors or
Treat as Annuals |
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Bog Lily Crinum |
Umbrella Palm Cyperus |
Water Canna Canna |
Papyrus Cyperus |
Elephant Ears Alocasia |
Taro Colocasia |
Non-Hardy Floating/ Submerged Plants |
Vallisneria |
Water Lettuce Pistia |
Anacharis Elodea |
Floating Fern Ceratopteris |
Water Hyacinth Eichornia |
Cabomba |
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Additional Bachman's Information
Ornamental Fish
Plants for Ponds and Bogs
Water Gardening,Cycle of Care
Wintering Your Ornamental Fish
Winter Care of the Pond
Recommended Products
Bachman's Quality Water Plants
MacCourt Rigid Pool Liners
Flexible Liners, Various Widths and Thickness
Little Giant Pumps
Pond Tab Water Plant Fertilizer
© Bachman's 2007 |
