I have yellow Japanese Iris plants. Can I harvest the seeds and plant? Before the winter comes how much of the leaves should I remove?
You can harvest the seeds once the pod has matured, and the seeds inside have darkened. You should not cut any foliage back unless it is dead, however. Cutting in green growth will introduce infection risk and cut off much needed nutrient storage. If you are dividing them, you can cut the top 1/3 of the leaves off, to force it to slow respiration. This helps during transplant.
This article will help you with the care of Japanese Iris: https://www.gardeningknowhow.com/ornamental/bulbs/iris/growing-japanese-iris-plants.htm
I have some iris ensata dinner plate cheese cake, I would like to know if the rhizome should be left exposed as with normal irises?
They will have the same care as a typical Iris. This article will help you to care for Iris flowers:
It is growing in the middle of jasmine in an outdoor garden that was planted about 6 months ago. If you are looking at the garden picture the jasmine is just in front of the palm and it's right in the middle. I have asked master gardeners, the earth box growers, and etc and no one can identify it. The bulb is huge on the bottom and it seems to be invasive because I know have about 4 of them. I live in zone 9, South Florida
This is, likely, an Iris. It may be Iris japonica/ensata, but it could be one of many closely related species.
Large clumps of the iris plants have what appear to be seed pods in place of where the flower was.
Yes, you can plant the seeds in the fall about 1/2 inch deep in amended soil. Wait till the pods start to split. They won't all germinate, but some will. And, since irises are hybrids, the new iris won't look exactly like the parent iris.