Winterizing pond plants

A gardener's work is never done. Fall is the time for winterizing everything, from irrigation systems, tools, and equipment to water features. Water features may include not only ponds and waterfalls, but also fish and plants. How should pond plants be prepared for winter?

Winterizing requirements vary, depending on the plants. It is essential to know your plants and their varying cold tolerances. Some plants are hardy and others are not. Instructions for winter care of pond plants often say to cut back a plant and put it in the deepest part of the pool for overwintering. However, this only works if the pond is at least 18 inches deep. Actually, sinking them deeper is better.

If your pond is too shallow, you can cut back the plant and bury the root mass in the ground, 4 inches to 5 inches deep, and then heavily mulch it. Plants that have been growing in the pond for weeks prior to the onset of cold will be hardier than any recent additions.

Hardy bog and shallow plants can stay in the pond all year. Trim back the leaves to about 2 inches above the soil level. Drop the plants in their original containers to the bottom of the pond. Leave cattail foliage attached until spring.

Hardy waterlilies need a deep pond that won't freeze to the bottom in order survive outside all winter. Otherwise, overwinter them inside. Store them either in their soil or as bare roots. Place them in a dark place where they will stay cool, but won't freeze - possibly in a refrigerator. Keep the soil slightly moist all winter. Bare-root plants store well in containers of damp sand.

Nonhardy waterlilies never go dormant, so they require more care through the colder months. Storing them as you would hardy lilies will give them about a 50/50 chance of survival. Instead of storing them, you might treat them as annuals and replace them each year. Or, if you would like to experiment, try placing them in an aquarium, keep them at 75 to 80 degrees, and provide them with strong light for 12 to 18 hours each day.

Nonhardy bog and shallow plants make nice indoor plants in the winter. Place them in saucers that contain water, and then put them in bright windows. Floating or submerged plants are often very tender and difficult to winter inside, so it is best to just consider them annuals. Otherwise, you can try the aquarium technique.

For more details on winterizing pond plants, check out Bachmans.com.

For more information on gardening, contact me, 887-2252 or skellyj@unce.unr.edu, or your local University of Nevada Cooperative Extension office. Check out many useful horticulture publications at www.unce.unr.edu. "Ask a Master Gardener" by e-mailing mastegardeners@unce.unr.edu.

-- JoAnne Skelly is the Carson City/Storey County Extension Educator for University of Nevada Cooperative Extension.