Autumn advice - maintain and clean the pond

Pond plant care & pond maintenance 1   2   3   4   5   6   7   8  

Why should you maintain and clean the pond?

Answer: To avoid algae and blanketweed growth next Spring.

Maintenance of the pond every Autumn:

    1. Net the pond to stop tree leaves falling into the pond water
    2. Remove any tree leaves that reach the water with a dipping net while still on the surface
    3. Cut back most upright marginal plant vegetation to 15cm (6") above the Winter water level
    4. Exceptions that should not be cut back are Cyperus involucratus, Eriophorum angustifolium, Equisetum scirpoides, Typha minima
    5. Reduce low growing foliage - old waterlily leaves and long stems from rafting plants
    6. Remove small amounts of accumulated silt by dragging a fine mesh net over the pond base.
  • Do not allow a compost heap to build up on the base.
  • Remove all dying plant growth to avoid rotting in Winter
  • You will get less algae bloom and blanketweed next Spring.
  • Tidy the pond and remove excess plant growth. Reduce clump size of rafting stemmed plants.
  • This allows maximum amounts of light to pass through the water to the submerged oxygenating plants in Winter.
  • Leave all oxygenating plants in the pond in Autumn.

Maintain and clean the pond little and often.


See below an 8ftx8ft pond: Photo after one seasons growth on LHS and after pond clean & cutting back in Autumn on RHS.

Take special care as you maintain and clean the pond out in Autumn:

  • Be aware of any banned invasive plants in your pond.
  • Check out our images on the Banned invasive pond plants page to identify all banned plants.
  • Compost these carefully and never throw into natural waterways.

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

  • This pond will have had leaves or excess fish food sink to the base of the pond
  • 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 some of the pond base in Autumn:

  • Remove the thick silt layer
  • 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.
  • Some silt left will  be a source of nutrient for waterlilies next year.
  • 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 other overwintering creatures like Great Diving Beetles.
  • 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 causes 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.

Major pond clean out:

  • Do any one-off clean out or overhaul an old, neglected pond in Autumn
  • Less wildlife species are in the water at that time of year.
  • Be vigilant to check and replace any creatures that are removed from the water accidentally.
  • Remove overgrown plants and decide how much of the clump should go back
  • Would that plant benefit from being divided and potted into more than one basket?
  • Keep as much mature water as possible in clean dustbins to replace back into the pond after the clean out
  • Top up with rainwater over Winter if possible.

Other Autumn pond tasks:

  1. Place any Half Hardy and Non Hardy plants into a greenhouse for protection.
  2. Place all waterlilies 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.
  4. Check for leaks or splits and weak spots in the pond liner and mend or add a patch of pond liner with waterproof adhesive

Spend more time now and see beneficial results next Spring.

  • Useful long armed pond gloves to clean and maintain the pond in Autumn
  • Cover the entire hand and arm in waterproof materials
  • Available in 2 sizes for both the smaller and medium/large hand size - there will be a pair to suit everyone!
  • No excuses! Clean out your pond now.

For related products - see below: