11/10/2025
Winter Hardy Pond Plant Species
In previous newsletters we have talked about the care of aquatic plants in NSP’s during the winter months. Now that we have moved into November, and we have several winter months ahead of us, we would like to look closer at aquatic plants in the winter, specifically which varieties of plants are best suited to the cold months and what benefits cold weather aquatic plants can bring to a NSP installation.
As we know, an essential component of aquatic ecosystems are the plants. They aid in oxygenating the water, filtering out pollutants and excess nutrients, and provide shade, food, and shelter for the pond’s inhabitants. However, different species are of course best adapted to certain climates, but how do you determine which plants to use in the first place? This should be done by consulting the plant hardiness zone map. Click here for an interactive plant hardiness map from the United States Department of Agriculture (USDA).
The Benefits of Cold Weather Pond Plants
Hardy pond plants will not die off in winter, which means less cleaning, shelter, and year-round oxygenation. If an NSP is in a cold weather zone, having plants that are either well adapted to the cooler climate, or are perennial and thus return year after year, will provide a variety of advantages. First, as opposed to annuals and tropicals, there will not be a need to spend money replacing plants in the spring. They will also provide water filtration and oxygenation year round. This is especially important in winter, as ice and snow can lead to a decrease in dissolved oxygen levels in the water.
In addition, although they will need to be trimmed, they will not completely die off and therefore won’t deplete oxygen or add extra nutrients to the water. They also provide a beneficial habitat and hiding spots for animals such as frogs who hibernate during the winter and would otherwise become easy prey if they are not hidden. Depending on the hardiness zone, some species of plants will tolerate the frost and cold weather better than others. Here is a list of some of the top hardy aquatic plants.
Top Winter Hardy Pond Plants
1. Water Lilies (Nymphaeaceae nymphaea)
This particular genus, nymphaea, of water lilies is well adapted to cooler/cold climates (typically zone 3 and warmer). With thick rhizomes that are able to subsist in substrate throughout winter and sprout new lilies the following year. Hardy water lilies are floating plants that make an excellent choice for cold weather ponds. Their broad leaves provide protection from both the elements and predators and their flowers are valuable to pollinators. They will need to be cut back as they are excellent growers and can start to spread too much. They can also be planted in pots placed on the bottom of the pond which will limit their spread.
2. Hornwort (Anthocerotophyta)
Also considered to be one of the most effective oxygenating plants, hornwort is a submerged plant that will also stay green throughout winter in most zones, providing oxygen and shelter. It does not reproduce overly quickly so there is little to worry about in terms of care of maintenance with this plant during winter or otherwise. They will either float freely about the pond, or they can be weighed down with small weights so that they stay put and don’t wind up in the filters.
3. Horsetail (Equisetum)
Horsetail, also known as scouring rush, is a prehistoric plant that’s been around for many millions of years. As such, it should come as no surprise that these plants are well equipped to persist through winters as harsh as zones 3 and 4. They’re considered marginal, preferring to grow either in damp soil or water that is only a few inches in depth. Like water lily, horsetail also has rhizomes. This is how they’re able to overwinter, as the main portion of the plant will die off while the rhizomes sit dormant in the ground or the bottom of the pond, giving rise to new growth the following season. Horsetails have native species on every continent except Antarctica, and so they generally don’t grow out of control like an invasive species would. In addition, their segmented anatomy makes them quite adept at filtering water.
4. Water Hibiscus (Hibiscus coccineus)
Also known as swamp hibiscus, this plant is classified as a bog plant that prefers to grow either in saturated soils or a couple inches of water. Water hibiscus has large, dramatic flowers that are typically red, pink, white, or some combination thereof. They provide shade, and therefore temperature regulation, along the edge of the water, as well as some protection from predators, while their striking flowers attract local pollinators. As a perennial plant, coccineus will die off each fall, but will sprout again in the spring via seeds that have been known to survive winters that reach as low as -30°F (zone 4).
5. Water Plantain (Alisma plantago-aquatica)
American water plantain, is a marginal plant with large, oval leaves, long stems, and very small pink or white flowers. Also a perennial they will die off in mid to late autumn, though its seeds will persist through winter and are hardy in zones 3 through 9. Additionally, the submerged portions of the plant provide habitat for aquatic invertebrates, which are in turn eaten by frogs, birds, snakes, and so on.
6. Water Soldier (Stratiotes aloides)
Another floating plant, water soldier is also known as water aloe or water pineapple due to its protruding, long spiky leaves. Though they look rather like a tropical plant, water soldiers have also developed an interesting adaptation to survive winters, even where temperatures go down to the negative digits. As water cools in the autumn, the main leafy portion of the plant becomes saturated with water, causing the plant to lose its buoyancy and sink to the bottom of the water where it is able to survive ice so long as the water is at least a few feet deep.
7. Pickerelweed (Pontederia cocrdata)
This is another popular aquatic plant for all zones, even to the top of zone 4. It is very popular, especially for northern water gardeners. Its carefree growth habit and boldly upright foliage is beautifully offset by its lavender blooms in summer.
8. Water mint (Mentha aquatica)
This strongly mint-scented perennial is for the boggy regions around your pond. If it likes the growing conditions, it can become invasive, but the lovely lavender blooms and its heady scent makes this lovely water plant well worth the effort of pulling out the overgrowth. Hardy to zone 4.
9. Lizard's Tail (Saururus cernuus)
This marsh plant has a compact, upright growth that can get very tall. In summer, it is topped by slender, white, spiky blooms. It gets very tall, and most of the plant stays underwater. It is breathtaking on the edges of a natural pond. Hardy to zone 4.
10. Arrowhead Plant (Sagittaria latifolia)
Arrowhead is a tall plant with graceful foliage and delicate, occasional white flowers. It is a vigorous grower, so for small ponds it should be contained in a pot. It is very popular with first time water gardeners, because of its ease of care. Allow plenty of room to grow this dramatic, carefree plant. Hardy to zone 4.
