Our pond is no longer clear as gin nor fresh as a daisy. We have algae.E
ven the word feels like an anagram of “plague” . Algae are simple plant life that live in or near water. They don’t have leaves or roots but they do photosynthesise. When it is warm and sunny they “bloom” and that’s when your pond goes green and looks like it is fermenting.
There is also another culprit in the pond which is in danger of taking over: Blanket Weed. These are long hair-thin strands of weed which multiply leaving a slimy shroud over your pond plants. My control method so far has been to scoop it out with a net but with all the warm weather we have been having it just returns two days later. I am also worried about scooping out the little invertebrates and tadpoles that have made the pond their home.
One reason we have been prone to blanket weed and algae is because we probably don’t have enough pond plants to use up the nutrients in the water. If they did the algae would starve. That was a good excuse to buy some more plants including another water lily. Floating plants are also good because they shade the water stopping the sun from warming it up and also stopping the algae from photosynthesising. It will take a while for the new lily to spread although there is a big fat flower bud on the surface tantalising us.
Another new method to try is water dye. Apparently this is popular with landscape gardeners especially with more formal ponds. The dye is black so it gives a beautiful reflection on the surface but also stops light penetrating beneath the surface. You may have noticed it being used in some of the water features at The Chelsea Flower Show. It is apparently totally safe for plants, fish and wildlife. I found a company that also does blue dye (which I thought a bit fake for my pond) but they also do a “shadow” dye – which is supposed to do the same job without the colour being so obvious. I don’t know if it is hokum hokum but I have decided to give it a go.
Meanwhile I shall have to rely on the water mint, which is putting out so many roots that it must be hungrily sucking up nutrients, and my two pond snails – although they seem to be busy cleaning algae off each other before embarking on the rest of the pond!