Water Hyacinth die every year


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Have had a pond for 15 years. For the first 10 years, my pond was about 2,500 gallons - with no filtration - just a fountain. My water hyacinth grew fine - although the water was smelly and gross. Five years ago, i rebuilt the pond (to about 4,000 gallons) and added a skimmer, and biological filtration. The water doesn't smell - although it is still green (I probably need a UV light) and it looks better. But - every year the water hyacinth slowly die off. They grow for the first two weeks or so, and then stop - and then slowly turn brown.

This has happened repeatedly for 5 years - I have no idea what the problem can be. Everyone else says that they grow like weeds. Mine used to - but now with the bigger pond, they don't.

I only have a few small koi (all the big ones died a few years ago from a heron) - so i know it isn't that the fish are hurting the plants.

Please help.
 
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j.w

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@captaintimmoss
I'm wondering if they don't need more fertilizer?
 

j.w

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But hyacinths are floating plants - how do you add fertilizer?
I've heard some here have taken the plants out and put into a tub w/ lots of fertilizer till they really get going. I don't have the plants so not exactly sure how they do it or what kind of fert they use. Hopefully someone can help you here.
 

YShahar

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I'm not sure this is the problem, but I also had water hyacinths die off for no apparent reason this year. By chance, I noticed that one was growing in a place inaccessible to the fish was still thriving after the others had died. So I placed a few of the next batch in a large plastic colander (the kind used for washing veggies) to see if that would help. The colander floats, but is tethered to the side of the pond to keep it from migrating toward the intake bay. Two months into the experiment and the plants in the colander are fine, while those that were free floating died back.

Tentative conclusion: the fish were nibbling on the roots to the point where the plants couldn't survive.

You might want to try a similar experiment, just to rule out fish nibbles as the culprit.
 
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Welcome captaintimmoss! Are you adding the plants at the same time of year as before? Is the water temperature and photoperiod about the same as before? Are the new plants from the same source?
 
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I've had years where my hyacinths did great and years where I couldn't keep them alive - in my big pond. In my patio pond and pondless they are 100% reliable. No clue what the difference is - same water, same fish, same pond. Different hyacinth stock maybe? I have noticed over the years that sometimes they are big, massive plants and other years they stay much smaller. So maybe that's it? Or perhaps your water isn't as nutrient rich as when you had a smaller volume with more fish. I do notice they do better when they are in shallower water and kept closely crowded together.

Keep trying - you might have a good year again!
 
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I have found them to be very finicky. If they are happy, they go like gangbusters! If not, they die. I just decided it's not me; it's them. :LOL:
 

cas

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Do you know the pH of your pond when the water hyacinths were growing well and now that they are not? I read that Water hyacinths like water with a pH of 7 or lower (but that isn't necessarily good for the fish). The first couple of years the water hyacinths did really well in my pond and the pH was about 7.5. In later years the pH of the pond increased to 8 and I have never had any luck with hyacinths since.
 
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You can remove them to a bucket with some 20-20-20 in the water and an airstone if you have one. Make sure to rinse them well before returning them to the pond. The fish will eat the new white roots growing under the plant. If all of those are gone it could be fish. For the first month I had my goldfish they refused to eat anything but hyacinth roots. I also tried placing the plants in a makeshift styrafoam floater with some window screen attached. After the water warmed up the plants grew like mad and by august I was culling them daily as they covered the pond.
 

j.w

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You can remove them to a bucket with some 20-20-20 in the water and an airstone if you have one. Make sure to rinse them well before returning them to the pond. The fish will eat the new white roots growing under the plant. If all of those are gone it could be fish. For the first month I had my goldfish they refused to eat anything but hyacinth roots. I also tried placing the plants in a makeshift styrafoam floater with some window screen attached. After the water warmed up the plants grew like mad and by august I was culling them daily as they covered the pond.
That's what I heard! Worth a shot and if one can protect the roots too then they just might flourish!
 
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no hyacinths here for a few years now. not since i built dead pool and the negative edge
 
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I'm not sure this is the problem, but I also had water hyacinths die off for no apparent reason this year. By chance, I noticed that one was growing in a place inaccessible to the fish was still thriving after the others had died. So I placed a few of the next batch in a large plastic colander (the kind used for washing veggies) to see if that would help. The colander floats, but is tethered to the side of the pond to keep it from migrating toward the intake bay. Two months into the experiment and the plants in the colander are fine, while those that were free floating died back.

Tentative conclusion: the fish were nibbling on the roots to the point where the plants couldn't survive.

You might want to try a similar experiment, just to rule out fish nibbles as the culprit.
I use a couple of those floating plant nets to keep the fish away from the roots. I have a weight tied to the bottom of the net to keep it expanded downward. As the plants start growing and filling the nets, I let some go onto the open water.

You can buy these nets or make them.
 
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Years ago hyacinths would bloom for me, but that hasn't happened for many years.
I couldn't tell you why. Could be a lot of reasons. Plants of different strains, Ph, nutrients? I have way too many fish, so it shouldn't be lack of nutrients. Maybe it's the lack of the proper nutrients?

The hyacinths and water lettuce multiply like crazy though and toward the end of summer I have to pull a lot of them out or they will completely cover the pond.
 
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JBtheExplorer

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They grow for the first two weeks or so, and then stop - and then slowly turn brown.

I had this same problems years ago when I first built my pond. I tried them for three years but they always did the same. Now they're illegal in Wisconsin so I couldn't get them anyway, but my pond gets nice and filled in now days with my waterlilies and bog bean.
 

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