Water Hyacinths

I live in southeast Pennsylvania. I bought four water hyacinths this spring. They began blooming immediately and continued for a few weeks then quit. The plants grew profusely throughout the spring sending out numerous daughter plants then slowed down into the summer. They seem healthy and are growing in height but still not blooming. All of the other plants in the pond are doing quite well and are blooming (if they are flowering types). Is this normal or am I missing something?

I love water hyacinth! I bought two small plants at Home Depot as soon as I saw them and they have grown out of control as well. Sometimes I will not have any blooms, and sometimes only one or two. Then sometimes they will go for a couple of weeks with no blooms. As long as they are in the water and green, I suppose they are alright.

I love them as well. I bought four this spring and was totally wowed by the flowers and now are my favorite flower plant in my pond. They have grow so fast that by early summer I was thinning them out, along with the water lettuce. They cover about half of my pond and do a wonderful job of shading the pond (the fish love it) and keeping the algae growth down. I just so much miss the flowers.

I just had to mulch about 200 water hyacinth plants because the Koi ate the roots and they were deteriorating. That many can cause a pond to go sour fast.

I have had water hyacinth in my ponds every year since I started ponding (5+ yrs). I bought approx. 7 this spring and have composted about 30-50 since then. I also gave some to a neighbor. The plants grow and send off shoots like crazy. The color varies from a medium light to fairly dark green. In all these years I've only had them bloom once. I really don't mind not have any blooms because I put wh in my ponds for the shade for the fish. I have wondered why they don't bloom. All my other flowering plants do really well.

I have a question for you. What is the pH in your pond? The reason I am asking is that I read an article suggesting that hyacinths are very pH sensitive. My pH is on the high side and I thought that might be the problem. I too will continue to grow them for the shade and algae control, but I really miss the incredible flowers.

Hey PHYLAL,
My pH is 7.2 which is in the normal range. All other parameters are right on except alkalinity which is a touch low.

I found this response to “Why Don't My Hyacinths Bloom” on another forum, it might help.

Mine never bloom either, and I think I know why. I fertilize my hyacinths by adding potash, nitrates, and occasionally iron to the pond water. They grow very well. They are big, green, lush plants, but they don't bloom. I keep them to remove phosphates from the pond water, and they do a wonderful job of that. The pond water is phosphate depleted, and algae free.
And that's the rub. Terrestrial gardeners know that adding excess nitrogen and minimal phosphate produces plants that grow well, but do not flower well. To promote flowering they cut back on the nitrogen, and add plenty of phosphate.
So, I think that is what happens to my hyacinths. It might be what is happening to your hyacinths. I don't know what nutrients are plentiful in your pond, so it is just conjecture.
Should you add phosphates to your pond to promote blooming? It would be a great experiment. I would love to see someone else perform this experiment. It might cause the hyacinths to bloom. It might also cause an algae bloom. There might be a certain amount of phosphate that would cause the hyacinths to bloom, but not the algae. I'm not going to do this experiment in my pond, because I hate algae.
If anyone takes the phosphate challenge I would love to hear all the details. Horton added some all purpose fertilizer to his pond once, and the algae didn't bloom, but I'm not sure he added enough to see a difference. I didn't hear if it made a difference to any hyacinths.
It would be hard to know how much phosphate to add. If you try to solve this, remember, it is an experiment. You don't know what will happen. Keep good records.

I suspect that this might be my problem as well because my hycinth are tall, dark green, and lush. I do not know if I will try this either, I hate algae. If anyone is willing to take the plunge, let us know.

Well, I do have blooms AND I have algae. I have been too lazy and/or broke to build one of these DIY Filters. I don't want to do the experiment but if you have no algae AND no blooms, and I have both algae AND blooms so maybe phosphates are the key. I would give up blooms to get rid of the alge which is probably what will happen. I will let you know when I get off my lazy butt and build a filter. We will see if the blooms go away with the algae.

Well, I guess I spoke too soon. I got up this morning and three of my hyacinths are blooming!!! I have blooms and no algae. I've done nothing to the pond and all my parameters are the same as always. Still confused but happy!!!