The water gardening season always seems to pass by a little too quickly. It seems that just as the water garden is looking at its fullest and best the autumn and winter are lurking just around the next calendar page. For many water gardeners the winter months mean that some changes need to be made in how we manage the water garden. We need to winterize our water gardens before the winter creeps back and lays its icy claim upon the land.
So we ask “how to winterize a water garden?”
How to winterize a water garden depends upon your particular water garden set up, however; there are some general suggestions that we all can follow whether our water garden is a lion’s claw antique bath tub or a large scale water garden of several hundred square feet. Which zone you are located in also plays a role in how and when you winterize your water garden. The first step towards getting ready for the winter months is to stop feeding/fertilizing your plants probably around mid-September.
Generally the best time to winterize is when the first frost hits your area. This time of year it is still comfortable during the days to do the winterizing work, and the plants can usually tolerate the cooler temperatures still. This time of year you will see some tell tale signs from your plants that it is time to do their winter pond preparation as well. Cooler temperatures will slow down vegetative growth and flowering, yellowing and browning of leaves begins, and if it gets too cold some of the plants will simply turn to a mushy mess. Ideally none of these materials should be left in the water garden pond for winter because they will further decay and foul the water, making the spring opening of the pond more of a chore. It would be good practice to deal with your tropical and floating plants first during the winterizing of your pond and then tackle the hardy aquatic pond plants.
The tropical floating plants can be saved by being brought indoors and kept in a container or simply thrown out, but try not to let them sink to the bottom of your pond only to decay all winter long. Tropical marginals or submerged plants also should be brought indoors and kept in a container with water. Tropical lilies and some other tropical aquatic plants can be removed and stored as roots or tubers.
Hardy aquatic plants can be left outdoors for the winter months, or if you’re up to a little extra work they can go indoors too. The submerged plants such as anacharis or hornwort can be dropped down to the lower areas of the water garden pond to keep them from getting too cold. It is ok to let them stay long for the winter but I prefer to cut them back to about a length of 6”-8”. Keeping these plants up higher will probably kill them only to mush over and decay. Hardy lilies are submerged plants, but generally they can be left where they are without the need to lower them in the pond. The dying leaves and buds of the lily should be pinched back to the crown of the plant.
Hardy marginal plants also should have their yellow or brown leaves removed, but after the first hard frost all the leaves should be cut back to about 4”-6” height with the crown of the plant about 1”-2” below water level. Having the crown of the plant below water level will keep the plant from actually freezing during the winter. Some plants such as the water iris can handle quite a bit of cold if you still want a bit of color and texture interest from your water garden late into the season. Once the leaves of the iris handle all the frosty nights they can, the leaves will brown and curl, it is best to cut them back at that point. “Super” hardy plants like cattail can even be untouched for the winter and it will likely bounce back just fine next season, although I prefer not to use the cattail in water gardens unless it is the dwarf variety.
Many of these winterization processes can be handled by your local pond professional. The Full Service Aquatics website details how a pond professional would handle the winterizing process. Your local pond professional is more than happy to help.
The main goal of winterizing your water garden is to not allow the roots of the plants to freeze as this will likely kill the plant. The reason we cut back and remove leaves is to keep them from getting into the water and decaying. The decaying material will just drag down your water quality. All water gardens are unique and will need some personalization as far as to the “how and when” the water garden winterization process is performed. With some simple steps and care your water garden can continue to delight you for year after year, only to grow back bigger and better as each season passes. Sometimes to see a water garden in its full glory will take many years, so proper plant care even during the winter when we are not thinking about our aquatic plants that much is important. If your water garden plants are not prepared for the winter, each season will bring new expense for replacing dead plants and delay the satisfaction of seeing your beautiful, mature, full glory water garden!
All copyrights to this material belong to Mike Gannon.


Susan Worthington

My pond is brick with a liner. This is the first winter I have had to care for it since my husband died. I have no plants, but I do have a 100-yr-old concrete statue fountain in the pond. Can you advise me on winterizing. I would like to empty the water and clean the pond out, remove the pump for the winter, and cover the statue with a large trash bag. Do you think I am on the right track?

Linda M Brown

I have Taro growing in my pond for the first time. How do I care for them over the winter. I’ve cut some of it back, but want to know if I need to bring them into my basement for the winter.

Mike Gannon

Hello Linda. I’m not sure what area you are in, but if you get freezing temperatures then I would bring the plant in for the winter. Taro can even make a great house plant during winter months so if you have the room to enjoy it then keep it close by, it would enjoy the extra light. -Mike


I have an aquatic hibiscus and a cardinal plant that sit barely in the water of my pond. They are gorgeous and I would love to keep them. Can they be winterized?

Mike Gannon

Hello Dee. They can be winterized but I don’t have specific directions on how to handle those plants, but would think some good info might just be a Google away! -Mike


Leave a Reply

Your email address will not be published. Required fields are marked *