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We have two ponds in our garden each had barley straw in it to help keep the water clear - have never really known whether this idea is proven or  not however, we had to clear out the smaller pond due to the dog pushing a load of rocks into it and I never replaced the straw - all this summer the one pond has been crystal clear (with barly straw) and the other has remained murky.    I kept leaving it just to see what would happen - so have I proved it works or was it just luck?

  • It works, I put straw in mine in the spring and autumn and have never had blanket weed, it also keeps duck weed under control too.

    As the barley straw rots it produces something (I think it’s an enzyme) which prevents the blanket weed from growing.

    Build it and they will come.

  • Hi Lucybob

    I recently looked into whether or not the use of barley straw had been proven to control algae, and it appears that science is a bit divided. But while we might be waiting for that final scientific proof, the weight of anecdotal evidence certainly convinces me that it is something worth people trying rather than resorting to chemicals. And with your email we have another lovely bit of anecdotal evidence to add to the pile - thanks :-)

    By the way, anyone wanting to try it, the recommended time to add the barley straw is in April.

    If you want to drop by my RSPB wildlife gardening blog, it is updated every Friday, and I'd love to see you there -

  • In reply to Adrian Thomas:

    I agree with you Adrian, according to farming friends who have ponds/lakes this does work.  We have just cleaned out our pond and are considering barley straw next year but how do we know how much to use? Any other advice would be welcome.

    Retired & loving it, a scot living in the south of England.

  • In reply to Zebedee:

    Hi Zebedee -  I purchase my barley straw from a garden centre (aquatic dept) and it tells you how much to put in against the size of the pond so guess they must be right as its working!  Will do as Adrian has suggested and change it next Spring and will put it in both ponds this time.  I think this was your first post?  If so welcome to the forum!

  • In reply to lucybob:

    Thanks Lucybob, its good to know the right stuff is easy to get hold of & use.  Good luck with both ponds next year.  Yes I am a new "poster" (if that is the correct term) thanks for the welcome. 

    Retired & loving it, a scot living in the south of England.

  • In reply to Zebedee:

    lavender suppose to do the same thing tadpols like green slime and so do water snails so how muce do i leave is the question i am asking my self also alot of water plants grow well under grean slime

    if i had fish it might be different as its wild life pond and wild life includes algea as its nuturel

    the friedly bid watcher

  • In reply to kristle:

    hi everyone.....

    I have three pools in my garden they are mostly man made and are all in differance sizes the large pool is 12 feet x 9 feet x 6 feet deep with shallows of two feet...

    This pond is home to 15 very large koi carp up to 24 inches long ( yes i breed koi carp) it as waterlilys and oxynating plants in... this pond would be full of blanket weed during the summer if it wasnt for the barley straw that i put in it each spring... even with two blanket weed controlers brought to controll it i still have to use the straw....

    The second pond i got is 6 feet x 3 feet x 4 feet deep and as koi and mixed breeds in... this is left as it is and in early may the blanket weed starts to grow strongly and i spend a lot of time pullin it out even thought this pond is left for wildlife...

    The last pond is a small pool about 3x3x3 that i use to bring the small fly on,  and i keep this spotlessly clean if i can......

    in all my years as a breeder i have tryed many things  and ways to controll blanket weed in my ponds, costing me £100's of pounds... only barley straw does the job....

    dont just look enjoy and leave for others to share after you. we dont own the earth we just rent a small part of it....

  • In reply to Kestrel ( Derek):

    Barley straw worked for me as well, but one thing I would add. We have a small pond on our allotment and used a net bag of the straw.we bought locally.  When we checked it we found a newt had been trapped. We stopped using the nets and would be grateful for ideas of how get the stuff to stay together in the pond. By the way, we found a live newt again this year. Not sure of the type, but we think it was a female smooth newt.

  • In reply to Linda Riley:

    Hi there,

    Instead of a net an old stocking or leg of a pair of tights would be fine.

    I know you say it was trapped but was it definately trapped? (I don't mean any dis- respect by the way, just not sure if it was alive or dead) it got in so could it have got out if it wanted too or do you mean it was dead?