This is the time of year when duckweed and green algae blanketweed may begin to reappear.
Duckweed:
- Unwanted Duckweed
- Has a 3 lobed leaf with a thread thin root
- It could have seeded down last Autumn and will rise up now
- Use a dipping net as soon as any piece appears
- Or it will soon cover the entire water area.
Blanketweed is a green algae growth:
- This looks like green cottonwool
- It will start to grow quickly in the warm weather of late Spring especially if you had large volumes of frog spawn jelly decomposing into the water this month.
- The Barleystraw product added in February/March should be having an inhibitor effect by now on this green algae growth.
- Newly hatched tadpoles will eat small amounts of blanketweed
- The rest should be overcome by waterlilies and other surface cover plants
- But you need sufficient to cover 50% of water surface in summer for balance
- Do not twist the blanketweed around a stick to remove it from the pond as that traps wildlife inside the twist
- Even leaving it in a pile on the pond side will not allow the creatures to get out.
- Unravel it and shake it over the water straight away to dislodge the trapped creatures.
Both duckweed and blanketweed are a nuisance & can be invasive. But they are not banned like some invasive plants.
Watch out for other invasive pond plants -
- Since 2014 there have been 8 aquatic plants banned from sale in the UK
- Deal with all these carefully if you already have them in your pond.
- Do not throw into open waterways.
- Compost with care or better still put into a green waste bin for collection and future disposal by professionals.
See our Tips and Advice page for images for identification: Banned invasive pond plants and our article on duckweed found here.