So when do all these pond plants supposed to go dormant?? The water temp. has gone down to at 60F by the time I've checked it in the mornings. My cotoneasters and mums on the outside are going dormant NOW but the trumpet liles are blooming again, and the purple spike flowers in the pond have 3 new flower spikes. (It's up to about 50 leaf stalks..it's huge ). AND the hyacinths are starting to bloom again. It's all going wacky down at the pond. I've lost about 3 inches of water, think I've got a leak..AARRGHHHH. :angry: Just not sure if I added water last weekend or the weekend before. ( I'll have to leave myself a note this time.) Can't wait until Indian Summer in New England, my head will be spinning pretty good by then. :(

SadieMae,
After the first frost last fall, all of my plants went dormant. That was when I started cutting the plants back. I think I took the water hyancinth and water lettuce out before then because it was looking not so pretty when it started cooling off, but before the first frost. Where do you live in New England?
Ellen

It's still 90 degrees F here in Zone 6/7. Here, I cut the pond plants down in November but they start to wind down in September. Since you're farther north, it will probably be late September or so before your plants die back enough to cut them down. It's affected by temperature, sunlight (rainy days), and frost. An early frost for example will cause lotus leaves to turn brittle and fall apart but if there's a late frost, they can go an extra month or so before being cut down. Some plants die back fast after a frost like pickerel weed and the tropicals like water hyacinth. Other plants like iris and hardy canna, being more hardy, don't seem to notice much and take longer to die back. My iris often don't show signs of leaf death at all so they're the last to be cut down, usually by then, there's ice.