You are in a warmer climate than I, so maybe you can winter them over easier. Usually we just toss the WH & WL in the compost pile in the fall and buy new in the spring.

As far as depth of water, I have some growing in about 1 inch of water in my skippy filter, so I don't think you need much.

Last winter I tried saving both WL and WH inside in an aquarium that sat in front of a window. All the WL did was get moldy and I threw it out. By spring the WH was still alive but down to a couple of small leaves. They did bounce back when I put them in the pond. I don't know if I will try again this winter.

There is a vocational school locally that has a heated atrium. They put WH in a child's swimming pool and I guess those do okay.

One possibility that I didn't try is to feed the WH with Miracle Grow as some have suggested.

Good luck!!
Anne

I am in zone 7 also and water hyacinth can sometimes overwinter; it's a major problem in some of the waterways around here, but the water in the "wild" is usually somewhat warmer than a liner pond. Water lettuce usually doesn't survive though. Can you corral some up in the corner of your pond and maybe put some clear plastic over that corner? They seem to be able to handle the cold better than the frost.

I have water hyacinths and plan to over-wintering them in a container of dirt that will be kept wet and in bright light. This is the way a friend of mine in Zone 6 does hers. Good luck. Oh, I had water lettuce but it has already turned to mush.

I live in zone 7 and over-winter several of my non cold hardy plants in the sun room. It is not heated, just gets warm during the day. I put 3 or 4 little WH and other plants together in a clear plastic tub that is about 4" deep, 20" x 10" or so. It is full of plants and I just top off the water weekly. This spring I had a surprise when I was putting everything back in the pond there was a gold fish in my little tub. This year I thought I would put everything plus a few fish in a bigger tub in the sun room and then I won't miss them so much.