How Do I Prepare My Pond For Winter?

How Do I Prepare My Pond For Winter?

To ready your pond for winter, start by adding your last dose of fertilizer in August. Just before your first frost, you should tend to all of your plants by removing and pruning all dead foliage. Do this for all plants you are leaving in the pond except hornwort, anacharis, vallisneria, and horsetail rush which can stay green. 
Taro and Canna can tolerate one good frost and then be dug up and tubers/rhizomes saved in onion bags in a cool, dark place through the winter. 

How do I prepare Hardy Waterlilies for winter:

1. Prune dead foliage, cutting it back below the water's surface
2. Place the container with the crown of the plant beneath the freeze line where ice forms in the winter.
   In the spring, the plant should send up new growth as the days get longer and water becomes warmer.

How do I prepare Lotus for winter:

1. Cut your lotus stems above the water line as lotus stems are hollow and you will drown the plant if the stems are cut beneath the water line.

2. Prune and remove all dead foliage.

3. Place your lotus container so that it is beneath the frost line,
   it is not wise to put them too deep*.
   Flip the pot and divide tubers every second year. 

 Pictured above is Laura Bancroft, tremendous friend, hybridizer and owner of Ten Mile Creek Nursery

How to overwinter Tropical Waterlilies:
The tuber method:

1. Stop fertilizing tropical waterlilies 60-90 days before pulling them for winter.

2. All tropical waterlilies should be removed from the pond before or after the first frost.

3. Cut the foliage back. It is then time to separate any tubers from the soil, Be careful, tubers, if any are present, will be close to the bottom of the stem and main root. Carefully remove the tubers and trim any remaining little roots. Tubers are generally small, usually the size of a dime to nickel. Some are up to the size of a quarter. 

4. Wash the tubers and treat with a mild fungicide. You may store your tubers indoors, in temperatures between 50-55 degrees in damp sand or better yet, in a small labeled baggie with just damp, mildly moistened Dacron cloth.

5. By the middle of February, stored tropical waterlilies can be planted in small pots with 3-6" of water above the soil and placed in a sunny location indoors or under a grow light with 1 fertilizer tablet in the soil. 

6. These waterlilies will have to be re-potted in the spring before putting back in your pond in the spring/summer and fertilizer steadily increased.

Tropical waterlilies are often treated as annuals and simply replaced the following year.

Method 2: Keep as a growing plant, bring indoors in a wide tub with clean water and keep the plant lightly fertilized and under grow lights 13-15 hours a day. It should need repotted in a larger container for year 2. 

How to Overwinter Tropical Shallow Water Plants:

1. You may bring indoors and use as a house plant or treat as an annual. Some plants require a lot of light in which case grow lights should be added. Many tropical plants require lots of sunshine, so place your plants in a sunny location such as a south facing window!  Grow lights are advised for most tropical aquatic plants such as tropical waterlilies. 

2. Many of the marginals only need to be kept moist, not entirely wet indoors when they will be nearly dormant. 

How to overwinter Floating Pond Plants (Water Hyacinth/Water Lettuce):

1. Most people simply treat these as an annual where you get repeated freezes and replace in the spring. .

2. You can bring these under full spectrum grow-lights. 14.5 to 16 hours a day of light and watch that the water does not become rancid. Usually there is rotting and the plants get very small.  

How to overwinter Oxygenating submerged grasses from the pond:

• Place your oxygenators beneath the frost line. You can do this by placing them on the floor of the pond.

• Depending on time the pond may be covered by snow which blocks the sun and can lead to plants rotting. A pond deicer not only helps fish survive winter it can let in just enough light to keep hardy submerged oxygenators growing. 

• Hornwort is most easy to overwinter anchored at the bottom of the pond. 

• Anacharis and Vallisneria can overwinter in zone 6 and sometimes 5 depending if you have enough light get through the ice. 

• All other submerged oxygenating plants are cold sensitive and should be overwintered in an aquarium or tank with grow lights indoors. 

Parrots feather, Water Hyacinths, Water Lettuce are NOT oxygenating plants, they actually block oxygen. 

Cabomba can take zone 7, sometimes zone 5 and 6 if you are very lucky. Most other submerged oxygenators survive zones 9 to 12 and sometimes zone 8. 

Nets, Debris and Pond deicers:
Winter Pond Preperation / Winterizing your water garden

• Clean out any debris, branches or leaves that may have fallen into the pond. 

• Remove plants that will not survive winter (tropical plants in areas it freezes)

• You may decide to place a net over your pond to keep debris and leaves from falling into your pond over the winter months.

• Consider the use of a pond deicer during the winter months, this will allow harmful gasses to escape through a hole in the ice. Fish perish most often from buildup of toxic gas below the ice and lack of oxygen in crowded koi ponds.

• Pond deicers (heaters) will kick on when the temperatures go below 32 degrees. 

• Many pond deicers are now energy efficient. 

• For the colder areas in plant zones 3, 4, 5 a 1000 to 1500 watt deicer is recommended. 

• In Plant zone 6 a 750 watt to 1500 watt deicer is recommended.

• In Plant zone 7 a 100 watt to 750 watt deicer is recommended. 

At this point, your pond should be ready for winter!