Winter in ponds

Winter in ponds

Winter has arrived very suddenly and our ponds in Leicestershire are now covered in ice and those further North are covered in snow.

Now that ice and snow has arrived it is difficult to work in your pond. Hopefully, you have done the Autumn jobs and there is not much leaf growth or many dead leaves in your pond water. We have tidied back the Nursery outside troughs so they have less foliage falling into the water too.

Any leaf debris will continue to try and rot down over the colder months. If ice remains over the pond for too long a pond can run out of oxygen to complete the rotting task. This can lead to some unpleasant gases in the water.

Remember not to cut back the evergreen pond plants that offer structure in Winter ponds and will not generally drop foliage into the water in the cold. Cyperus involucratus  Eriophorum angustifolium  Equisetum scirpoides  Iris Louisiana Black Gamecock  Juncus ensifolius  Typha minima. Of these Cyperus involucratus  Iris Louisiana Black Gamecock  Juncus ensifolius and Typha minima will all need tidying in the Spring but not until you see the new shoots pushing through.

The only pond plants that flower in Winter are Aponogeton distachyos on the water surface.

Wildlife in Winter ponds

The unpleasant gas build up can kill any wildlife that may have remained in the water overwinter. Melting a hole in the ice will not help to add enough oxygen back into the water. But you can melt a hole in the ice using a metal saucepan so it melts gently to allow birds to drink. Don't smash the ice!

Clear any fallen snow from the ice with a broom as far as you can safely reach so that submerged oxygenating plants can see more light. Ceratophyllum demersum is the best oxygenating plant in Winter - even though it has dropped to the bottom of the pond and gone blacker in colour. This allows them to be able to produce as much oxygen as possible with photosynthesis. You can help reduce the likelihood of wildlife 'Winterkill' by maintaining good oxygen levels in the pond. We encouraged you in our Autumn post to leave the thinning out of deep water oxygenating plants until Spring. These will drop into the deepest water of the pond now to avoid being trapped in the top layer of ice.

Most wildlife will have left the pond and found shelter and protection under plants nearby, under a shed or in a log pile.  There is still time to create a Bug House or hibernaculum to give them shelter if you can collect fallen tree leaves or pick up twigs, logs and fir cones on your Winter walks. Try not to disturb any established piled up areas with too much garden tidying now!

With Winter snow and ice around now it is better for everyone - us and the wildlife - if you leave the tidying of the garden until Spring!