Maintenance of the pond every Autumn:

Question: Why should you maintain and clean your pond?

Answer: To avoid algae and blanketweed growth next Spring.

    1. Remove any fallen tree leaves with a dipping net
    2. Cut back any upright marginal plant vegetation to 15cm (6″) above the Winter water level
    3. Remove low growing foliage – old waterlily leaves and long stems from rafting plants
    4. Remove small amounts of accumulated silt by dragging a fine mesh net over the pond base.

If you regularly (at least annually) remove leaves and vegetation from your pond and do not allow a compost heap to build up on the base then you should be able to avoid a total clear out of the pond water for many years and will get less algae bloom and blanketweed next Spring.

Tidy the pond and remove excess plant growth. This allows maximum amounts of light to pass through the water to the submerged oxygenating plants in Winter.

Leave oxygenating plants in the pond in Autumn.

Little and often is the motto with pond maintenance.

See below an 8ftx8ft pond after one seasons growth (LHS) and how it was left after an Autumn maintenance (RHS).

A sign of a pond in need of extra attention is its smell:

  • This smell comes from the layer of silt/sludge at the bottom of the pond and is caused by the incomplete rotting of vegetation due to the lack of oxygen (anaerobic).
  • If there is not enough oxygen in the water the rotting process (the Nitrogen Cycle) cannot complete resulting in the production of other gases – methane and hydrogen sulphide (the smell of rotten eggs) which are noxious to fish and other living organisms. 

To clean the pond base in Autumn:

The task is to remove any thick silt layer and do a partial water change to reintroduce oxygen to the system and remove the overload of rotting material.

Use a Pondvac – you can ‘hoover’ the pond base which will remove silt and some water.

Do not be paranoid – you do not need to remove all the silt – look out for dragonfly and damselfly larvae using it as a hiding place and for some overwintering creatures like Great Diving Beetles.

Some silt will also be a useful source of nutrient for waterlilies next year.

Or in a small pond use a fine, flat edged dipping net which you can drag cross the base of the pond and lift any silt into a wheelbarrow for redistribution on the veg patch as a good source of nutrients.

We recommend you net across one half of the pond floor one year and the other half the following year.

Alternatively, use Mud Muncher.

  • an environmentally friendly solution to the build up of sludge and mud in ponds.
  • a blend of live bacteria that contains no herbicides or pesticides.
  • It digest organic matter such as fish waste, fallen leaves and decaying plant matter, which can cause the build up of sludge.
  • Helps eliminate odours and reduces the need to clean out ponds and filters.
  • Safe for fish, wildlife, pets and plants in the pond.

One off total pond clean out in Autumn:

If you have inherited a pond that has been neglected and requires a major overhaul the best time for that is Autumn.

1. There is less evidence of wildlife species in the water at that time of year but still be vigilant to check and replace any creatures that are removed from the water accidentally.

When any horizontally growing and surface cover plants are removed from the pond in Autumn –  check that you have not also removed wildlife creatures

  • Dragonfly larvae spend several years under the water before emerging as adults and these larvae easily become removed from the water when you are removing plant growth.
  • Late hatchings of newts can also still be in the pond and being only 1/2″ long can be difficult to spot.
  • Backswimmers or Greater Water Boatmen will also become trapped if you collect armfuls or netfuls of plants in a mass.

Make sure you shake the plants you are removing over the pond to free the creatures – leaving the plants on the side of the pond is not sufficient – especially if you have twisted the plants or the blanketweed into a ball or tight clump – they need to be unravelled, opened out and shaken.

2. Leave oxygenating plants in the pond – do not thin out before Winter as the better oxygenated the pond in Winter the better it is for any wildlife that stays in the water. You can thin out in Spring.

3. Remove overgrown plants and decide how much of the clump should go back and if it would benefit from being divided and potted into more than one basket (if space in your pond allows.)

4. Try and keep as much mature water as possible in clean dustbins or the like to replace back after the clean out and then top up with rainwater if possible.

Other Autumn pond tasks:

  1. Check that all Half Hardy and Non Hardy plants are placed into a greenhouse for protection.
  2. Check that all waterlilies are low enough in the water to be below any expected ice level in your area.
  3. Check any plants for duckweed and wash them clean before replacing them in the pond.

More time spent now will be beneficial in the months ahead.

These are the useful long armed waterproof pond gloves for doing Autumn maintenance in the pond. Available in 2 sizes for both the smaller and medium/large hand size and elasticated at the top. They allow you to work out in perhaps cold and certainly wet conditions and complete the job well.

There should be a pair to suit everyone! No excuses!