Hi rams, I am zone 5a. I have the same lizard tail and marigold plants in my pond since it was build 3 years ago. Actually I will be splitting most of the plants for my new pond next spring. Marigold are usually dried up by the summer heat. I do like keeping them in the pond because they are the first plant to bloom in spring. When your closing your pond for the winter, cut back the marigold and lizard tail to 2 inch stocks. Cut off anything dead. I never used the other two plants. Grasses I'll snip the top inch or so to get rid of the dead stuff. Then put the pot in the deepest part of your pond for the winter. My pond is 2 feet deep and they do well. Hope this helps.

Thank you, Craigger7. Other plants I have are yellow floating heart, pennywort, primrose creeper, water forget-me-not, and hardy thalia. So, if you have experience with any of those I would love to hear about it.

Thanks, again!