Prepare Your Plants for Closing Your Pond

Often the plants we buy from the store to decorate our ponds and filter the water are not native to where we live. Some plants are from warm tropical environments and can't survive a harsh winter. A plant's hardiness determines how cold-tolerant it is and how you'll need to take care of it during the wintertime. Some plants need to be relocated indoors, while others just need to be pruned or moved to the bottom of the pond.

Guide to pond plant care throughout winter:

Surface Plants:

• When it starts to frost, remove to compost
• Replace each year

Hardy Surface Plants:

• Leave alone
• They will sink to the bottom of the pond and reappear in spring

Tropical Marginals:

• Move indoors before the first big frost (keep at a minimum of 65ºF/18ºC with sunlight or grow light).
• Return to your pond when it has thawed, and you do not expect any more freezes.

 Tip: They can be planted without being submerged in water

Tropical Tubers:

• Must be moved indoors (keep in water with a minimum temperature of 70ºF/21ºC to keep plant active or store them in sand or peat moss to have the plant be temporarily inactive).
• Return to your pond when it has thawed, and you do not expect any more freezes.

Hardy Marginals & Bogs:

• Move to the deepest part of your pond for winter if your pond is 18 inches or deeper.
• Relocate indoors if your pond is not 18 inches or deeper. Store in cool water until your pond has thawed, and you do not expect any more freezes.

Submerged Plants:

• Move to the deepest part of your pond for winter.

Certain plants like to be stored inside and require water. Others will be happy potted on a sunny windowsill inside. As a rule of thumb tropical plants are not equipped to handle cold water and need to be moved inside. 

Hardier marginals can trimmed back and moved to the bottom of the pond where the water will be warmer (assuming the pond is deep enough and will not freeze all of the way through).

Many surface plants, like water hyacinths, are inexpensive and difficult to winterize. They can be composted and repurchased in the spring. Keep in mind that these plants are invasive and should be composted properly, away from water sources. Composts make for great DIY fertilizers, packed with all-natural nutrients.

Debris is a concern during winter, as the good bacteria slow down, leading to build-up during the winter. You can use a skimmer net to scoop out any falling leaves or set up a pond netting if your pond is located directly under a tree that will shed its leaves. 

Pruning is necessary for many of the hardier plants that will ride out the winter in the pond. Plants like cattails and rushes with hollow stems should not be pruned to help prevent rot. They need to always be kept above the water line.

If properly cared for in the fall and winter, your plants will be ready for spring when the weather warms up. Once the water temperature in the spring is consistently 70 (21°C), you can move the less hardy, tropical plants back into the pond. Winterization is easy when planned out and started in the fall. By the time the snow falls, you will be ready to relax and have a worry-free winter.