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Overwintering pond plants – How to keep aquatic plants safe until spring with simple steps.

You have created a garden pond with aquatic plants, but you do not know exactly how to overwinter your pond plants? At first glance, this may seem difficult, but with proper plant care, your plants can survive the cold season. In doing so, it is important to prepare each plant variety for low temperatures before winter sets in. This will depend on the types of plants you have in your pond. Here is some important information and steps you can take to keep your plant life alive during the winter season.

Maintaining your own water garden and winterizing pond plants

prepare the garden pond for the cold season in autumn and take care of the plants

Before winterizing your pond plants, remove as many dead leaves and debris from the pond as possible. Any wilted plants around the edge of the pond should also be cut back. Removing rotting leaves and other debris that have fallen into your backyard pond will help reduce toxic gases, such as hydrogen sulfide, that build up in the pond during the winter season. These gases are toxic to fish. In addition, some plant species cannot tolerate winter temperatures and need a safe place to survive. However, for hardy specimens, winterizing pond plants may simply mean submerging them under pond water.

frozen plants around a pond in the winter season

So before you get into it, it’s important to winterize the pond itself. This will help keep the ecosystem healthy, keep your pond fish alive during the winter, and of course, help any plants you want to overwinter in your pond.

koi fish in the garden pond and pond plants overwinter with the right plant care

Hardy pond plants are perennials that grow or survive and go dormant during the cold winter months. Non-hardy plants, on the other hand, will die if left out during the winter. You should winterize your pond plants when the first frost arrives. It’s best to categorize aquatic plants to determine a course of action for plant care.

How to winterize your pond

winterize the garden pond and remove the pump with the filters

  • First, remove leaves and debris from your pond.
  • Cut back dead or dying foliage from your pond plants.
  • Add beneficial bacteria for cold water (optional).
  • If you fertilize your pond plants, you should stop once the water temperature reaches about 16 degrees.
  • If you have a water pump, you should remove it, clean it and store it properly.
  • Also remove and clean any filter media.
  • Add a pond heater or de-icer to your pond if needed to keep it from freezing completely and allow for proper gas exchange.

How to overwinter hardy pond plants.

overwintering pond plants and winter-hardy varieties at the first frost in autumn

Most cold-tolerant aquatic plants go dormant over the winter months and foliage dies, so you can stop fertilizing when the weather cools. Hardy water lilies, for example, are among the most popular pond plants and don’t need much care in the winter. Just cut back yellowing leaves and move the pots to a deep part of the pond where the water is warmer in winter. Lotus can be treated the same way and can survive the winter as long as its tubers don’t freeze.

overwinter hardy pond plants and leave them cut back in the pond water

  • Cut off any dying or dead leaves from the plants. If you are winterizing hardy water lilies, you should cut the plants back to the crowns.
  • Sink the planters in the deepest part of your pond where the water temperature is a few degrees warmer. It is recommended that the pond be at least 80 inches deep.
  • Return the plants to their original location in the spring after the ice has melted.
  • If your garden pond is too shallow to overwinter plants, you can store them in a Styrofoam cooler in your garage at 5 degrees. Keep them cool, moist and protected from light during this time.
  • Some bog plants can actually be left in place through the winter. Simply prune them to just above the water level.
  • Remove any dead or dying leaves from the plants in the spring.
  • Do not allow the bulb or rhizome of hardy plants to be exposed to actual freezing water or covered with ice. This can cause aquatic plants to turn to mush and not hold out until spring.

Winterizing aquatic plants with cold intolerance.

fish out cold-intolerant aquatic plants and keep them indoors during winter

Non-hardy pond plants can be grown as annuals in areas with low winter temperatures. Accordingly, you can remove floating aquatic plants such as water lettuce and water hyacinth from the pond before winter and compost them. However, such plant species are invasive in many areas. Therefore, it is important to ensure that they are disposed of properly so that they do not enter public waters. You can make overwintering of other non-hardy aquatic plants possible by simply maintaining them as houseplants. Simply store the plants in a saucer filled with water. Place them in a sunny window or use a grow light with a timer set for 12 to 14 hours a day.

cut the stems of aquatic plants with garden shears and overwinter the pond plants

Non-hardy plants mostly include tropical plant species that grow outside the winter hardiness zone. So in summary, when dealing with non-hardy pond plants, you have two options in the winter:

  • Move the plants indoors so they don’t freeze and die.
  • Treat the aquatic plants as annuals and replace them after composting in the spring.

If you choose the former, remove the plants from the pond before the first frost and bring them indoors. In order for you to overwinter such pond plants, they must remain in the water and have a temperature of at least 18 °C. As written above, depending on the type of aquatic plant, they need up to 10-14 hours of sunlight per day. You can return the plants to your pond or water garden in the spring.

prevent frost on the leaves of garden plants during the winter season

So with a little careful preparation, you can ensure that your pond plants will survive the cold winter months. If you have a small garden pond, it only takes an hour or two to winterize your plants and you can look forward to healthy, thriving aquatic plants in the spring.