To combat Algea, Blanket Weed and Invasive aquatic species you need to be on your guard.

A small wild life pond doesn’t have to be weedy in either sense. This pond in our park for example is a fairly large size. However as you can see it is ‘Weedy’ in the gardening sense.

Removing Blanket Weed

• Oxygenating plants are the best and organic method but may fill half the pond.
• For a small pond you can try the winding it around a stick method but roots regrow and small critters may be thrown on the compost heap with the weed.
• Sun causes growth of blanket weed and a covering of water lilies will help keep it down
• Hydrogen peroxide inhibits all algae growth and this can be created organically using straw bales made from Barley – Put some in a stocking for a smaller pond or try a chemical concentrate
• UV filters are expensive but if you want to be sure to see your fish hang the expense.

Algae and Other Pond Weeds

• One easy way to get rid of an algae mess is to dredge or empty your pond. This is obviously impractical in many circumstances.
• Increased circulation in the pond will stop algae.
• Grass carp love to eat pond weeds and plants whilst young grass carp will feed on algae.
• Biocides and special herbicides can also control pond weed
• Some weeds can be lifted out or twisted around a stick and pulled out. Leave on the side to let creatures return to the pond before composting.
• Cover the pond so leaves do not accumulate. They will rot and gases given off will damage oxygen levels for fish.

Get blanket weed buster from Amazon as a Christmas present.

Invasive Aquatic Plants

• New Zealand Pigmyweed or Swamp Stonecrop Crassula helmsii forms a dense mat that reduces light and displaces native plants.
• Water fern Azolla filiculoides or Fairy Fern. Easily transfers and can rapidly blanket the top of a pond almost looking as though children can walk on it. Green in summer turning red in autumn.
• Floating Penywort Hydrocotyle ranunculiodes grows rapidly 8 inches a day. Reducing oxygen and thick enough to look like dry land it is a major danger.
• Water Primrose and Parrot’s Feather are also in danger of clogging waterways and out-competing native plants.

See our report on ‘Organic pond habitats for green gardeners’.