Caring for Pond Plants During the Winter
Author: Terry Newhaven
For people still developing a green thumb, winter can bring with it tons of confusion. To help make sense of it all, get yourself a handy-dandy Zone Hardiness Chart and use it to figure out which of your plants are hardy in your zone. It also helps to remember that there are many factors to consider for each plant when it comes to overwintering. We'll help you understand overwintering so that you can save your plants' lives from the harsh winter and continue to cultivate an amazing pond or water garden full of beautiful blooms.
Hardy vs. Non-Hardy- Plants generally fall into two categories: hardy and non-hardy. The hardier the plant is for your zone, the more likely it is to survive the cold season once dropped to the bottom of the pond. Non-hardy plants generally cannot survive the winter season and you will have to make other arrangements to keep these plants alive. Otherwise, treat non-hardies like annuals and simply buy them again when they're in season. The best thing to do with a non-hardy plant is to toss them into a compost pile once they're damaged by the first frost. This alleviates your filter system of any extra work of ridding your pond of useless debris that can cause problems for you later.
Hardy plants can withstand the cold because ponds (depending on size and depth) are at least slightly warmer than the air temperature during the winter. To over-winter your hardies, clip off the foliage after it has been damaged by frost. Prune away all the foliage until you see the crown of the plant, the center from where all stems emerge. Then place the pot at the bottom of the pond where the water is warmer than the air.
Marginals - Marginals don't have to be submerged, so their indoor maintenance is easy. All you have to do is place a saucer underneath the pot and keep that saucer filled with water at all times. Keep them in a sunny window for best results. If you have more than a few, a cheap kiddy pool can be an easy fix. Set up in a spare room with a lot of light (like a guest room) and keep a few inches of water in the kiddy pool at all times. If plants are in a dark room, like a basement, purchase a couple of grow lights and set the timers to keep the lights on about 12 hours a day. This will ensure that your marginals make it through the winter to be transferred back to your pond after the winter season.
Oxygenators - Like hardy lily varieties, most oxygenators are already submerged and can withstand the winter weather because the water temperature is slightly warmer than the air temperature. Just make sure to sink these to the bottom of the pond and you don't have to worry about a thing. If you have any fish, they may eat at the leaves of these plants out of sheer boredom, so you might end up replacing them in the new season anyway.
Again, consult a Zone Hardiness Chart for more information regarding your hardy zone and other factors that affect your pond plants. Also, if you find a few blooms that still look great, just snip them off the plant and place them in a vase and enjoy the vibrant colors for a few more days.
Lotus- Like most hardy plants, prune away all leaves and stems after frost has done its damage. Sink lotus plants to the bottom of the pond where the temperature is warmer. Many people bring lotus plants inside for the winter as well. Lotus plants do need a cool place to ensure successful overwintering. It needs to be cold enough for the lotus to go into a dormant state, but warm enough so it won't freeze.
Hardy Lilies - Prune away frost-damaged leaves and flower stems and sink them to the bottom of the pond.
Tropical Lilies- Tropical lilies are a bit trickier to survive winter. Because they're only hardy to zone 8, many people aren't willing to do a little work in the fall, opting to replace them every spring or summer. If you'd like to save your tropical lilies, remove the plant from the pond before the water temperature drops to 55 degrees. Rinse away the soil and remove the tuber from the root's bottom. The tuber is shaped like a walnut and should be dried out for a couple of days and then placed into a jar of distilled water and kept at 50-55 degrees or so. Then take the tuber and place it into a container or large saucer of water with some sand in the bottom. When the tuber sprouts three or four leaves, snip off the tiny plantlet below the new root system and plant it in a small pot with soil. Water and keep it at 70 degrees. bring the pot into the house and set it down in a large container or saucer near a sunny window. No need to submerge, but do remember to always keep water in the saucer or container, as the soil must stay wet. It'll take 2 to 3 months for the first flower to emerge. But by snipping off the flower buds from the old plant and placing them in a vase, you can continue to enjoy the blooms for a few more days.