My guide will help you to understand duckweed in your pond, explaining what it is, how it can affect the pond, and how you can control it.
The common name is Duckweed and it's botanical name is Lemna minuta. It can be a real nuisance, especially if you're trying to keep your pond clear. Many people report that once they've rid their pond of green water and blanket weed the next problem that arises is Duckweed.
The reason for this is because it feeds off the nutrients in the pond, just like green water and blanket weed do too, so once the others are out of the way duckweed is free to feed all it likes, multiplying and covering the pond.
During the Summer duckweed can quickly multiply, especially in slow moving or still water. It has been known to double in quantity at times in one day.
What Does Duckweed Look Like?
It looks like hundreds of tiny leaves around 50mm in size, a bit like water cress they won't get any bigger than this size. They will usually appear in the Spring and sinking to the bottom of the pond in the Winter and surviving, returning next year. It stays green through the Winter so it's easy for you to spot and remove from the pond.
Where Duckweed Comes From
Duckweed can be introduced into your pond by accident on plants you've been given or bought or through animals like birds, this is sometimes unavoidable so be prepared to one day face the problem of duckweed if you have a pond but have not yet experienced it.
The easiest way to stop duckweed from entering the pond on new plants is to isolate them from the pond for a couple of weeks before introducing them, this can also stop blanket weed problems too.
Can it Be Treated?
The best way to manage duckweed is through regular raking and collecting with a pond net to reduce the amount in the pond, you can even use it in your compost too, the nutrients will really help.
The other option is to use a pond duckweed treatment but this can take a few weeks to work, so if you're clearing the pond for a garden party then it's probably best to go with the first option of manual removal.
As it is natural duckweed can easily return through one of methods mentioned above so always be alert.
Read my guide to Pond Blanketweed.