soil advice for nasturtium and zinnia

Can anyone tell me what kind of soil these perfer? I've become confused (doesn't take much, lol) since reading in some places that zinnias perfer "poor" soil. I have heavy clay soil and have been ammending my beds with compost and perlite. Then I read someplace that zinnias bloom better in sand?

If anyone can help or offer advice on this, please do!

Thanks,

Maureen

Nasturtiums will grow about anywhere. I have clay soil and they love it. The zinnias do fine as well. I ammend with compost/manure and redwood bark-when I can get it.

Thanks that's good to know, I have clay soil as well. Glad to know I don't have to worry about amending that part!

Maureen