It looks like it's a soil issue to me, either a nutritional definciency or a soil moisture issue, though I don't know enough about either one to be able to tell you what exactly. What did you use for the potting medium?

Perhaps a guide to nutritional issues might help, something like this one from AZ extension. I searched for "leaf nutritional problem plant."

Thanks. The site helped. I will repot with amended soil. Looks like a magnesium deficiency. -Nancy

Look in the container forum for suggestions on container soil since you will be growing these in pots for a while I assume. One of the issues with potting soil is that it really isn't designed for longer term use; it usually doesn't have complete nutrients and it breaks down over time, reducing pores that allow water and air movement. There will also be info on fertilization I imagine.