Blanket Weed removal and its prevention

When it was terribly overgrown with brambles my pond didn't have a blanket weed problem, but now I've cleared away the brambles the sunlight can of course get to the pond it seems to have spurred on the growth of the weed.

Is anyone able to recommend anything that is wildlife and garden plant-friendly that I can add to the pond to either kill off the blanket weed or, once the weed is removed, prevents its regrowth?

There's not much in the pond - a few lillies, some water grasses of various types at some edges and, for wildlife, some newts and maybe a few tadpoles.

 

We use Swell Blanket weed sachets (swell.co.uk) claims to be wildlife friendly and certainly doesn’t seem to effect ours (we have newts, frogs, dragonflies etc). It works better than anything else we have tried although Im not sure you can ever completely eradicate it. I also do the occasional twirling session with a beanpole (especially if growth starts early when temps are still low)

 

Thanks very much. I went to swell.co.uk and the site deals with hair products ....... :-)

It's actually swelluk.com for the blanket weed remover, etc:

https://www.swelluk.com/swell-control-green-water-and-blanket-weed-combo-pack

I notice that you're supposed to put it in the filter, however I don't have a filter in my pond or any kind of running water - it's simply a hole in the ground with a liner and an outlet pipe to maintain the water level. Can it just be thrown into the pond?

Also, will it clear existing blanket weed or does that need to be manually removed first?

 

Whoops! But glad you found the right website.

We just throw the sachets into the pond, like yours we don’t have running or recirculating water.

I can’t recall what we did when we first tried it, I think we probably removed as much as we could first. It was pretty rampant at the time

 

Thanks, mine is pretty rampant too. Just removed a load covering about a quarter of the pond but my muscles are complaining so I'm taking a break. Probably have another go tomorrow.

I now need to measure the pond to get an idea how much to use of the weed control.

Did you also get the stuff for green water, or just for the weed?

 

Ours is just for the blanket weed. The water itself is lovely and clear and once we had the dreaded BW under control always has been

 

Blanket weed loves a clear space, so more plants help, but that can also take a bit of time to get the balance. Algae loves warm conditions, so anything that floats, and therefore covers a large amount of the surface area will help. Watercress is good for that , and it also takes up a lot of the nutrients that the algae likes. I just get a bag from the s'market and chuck it in.
I also do some twirling with a cane, but I've used one of the proprietary blanket weed products that you chuck in. I'll see if I can find which one it was - I got it from one of the well known pond product suppliers.

It was this one -
Cloverleaf Blanket Answer - Pond Treatments - Bradshaws Direct

 

The Cloverleaf product is very popular with koi keepers so I'm sure you can read many experiences with it. I've not used the product but have heard good things.

One of the biggest problems this time of year is the extra sunlight whilst the pond is still cool and the plants not rapidly growing. In our wildlife pond we have most of the water planted and only use rain water, this means that after a year or two to settle, we don't really get any algae unless we remove to much vegetation at the wrong time.

 

The main problem I had was that a lot of my pond was very shallow @Thevictorian , so the water warmed up very quickly. It was impossible to get the depth I wanted at the time I was doing it, but I've been digging it out recently to make it deeper.
This thread has just made me wonder if I should get some more of thet product though - just in case

 

I opted for trying to cover the surface of the pond with plants, lilies and water hawthorn are doing a pretty good job in our pond without using any chemicals.

 

I always find that the algae gets growing before the plants, I have far too many fish in my pond which doesn't help.
If you don't have fish I think algae should be less of a problem.

Having said that nearly all my pond is now covered with watercress that has overwintered in there this year.
I will need to remove some at some point but picking the right time is going to be the problem.
I have in the past used a product from a local garden centre which works well but slowly, I'm always wary about products that clear the water, don't harm fish, but affect normal plant growth, I've been mislead by a few of those over the years.

It's worth remembering that most koi keepers don't grow plants in their ponds

 

You can treat blanket weed with a mesh bag full of barley straw. I looked it up on the RHS site and it says:

• Float a mesh bag of barley straw on the pond – about 50g of straw per sq m (1½oz per sq yd) of water surface area is ideal, and should discourage all types of pond algae. Add the straw in spring and remove it when it has turned black (usually about six months later). Sometimes lavender is added to the barley straw for additional effectiveness
  

 

It never worked for me, but I know it is considered an environmentally friendly method.
Often see tiny packs of barley straw for sale for that purpose at completely stupid prices.

 

I never found the straw to be any good, regardless of the size of the pond. Like @burnie , I always found having good cover on the surface helps most, but this pond was too shallow, so I decided to get the treatment. I don't know if I'll bother again though. I'm hoping that now I've got a better depth on the edges, it'll make a difference. I quite like twiddling the blanket weed now and again!

Water hawthorn is one of my favourites too, and it self seeds quite readily, and the little lily has grown well so it's all been divided. The forget me not has spread well too, so I've been doing quite a bit of work generally with the pond, and it's all starting to look good. I'll see what it looks like in another month, and maybe look for a couple more plants...

 

I always found water hawthorn goes dormant over the summer, so spring and autumn it flowers for me.
I've got a yellow water lily that covers a lot of it in the summer plus elodea under the surface, I dont really go in for marginals much now.
I had a red water lily but it was far to vigorous for the size of my pond.