Understanding blanket weed
Blanket Weed is a form of filamentous algae which will grow to carpet the surface of the pond and areas of flow (e.g. waterfalls). There are several factors that can cause excessive growth of Blanket Weed and although an effective treatment will remove algae the causative factors must be addressed to prevent further outbreaks.
Major influencing factors are:
Excess sunlight so you may benefit from adding floating plants – e.g. Lily’s and water soldier – to cover up to 50% of the pond surface area or use planting around the pond to create areas of shade across your pond. You do not want to completely shade the pond as this will discourage good plant growth, however finding a balance could reduce the recurrence of Blanket Weed
More nutrients than your existing pond plants can use which stimulates algae growth. Nutrient levels can be controlled by encouraging plenty of healthy fast growing pond plants and regularly removing waste and sludge from the pond.