I've got a lovely crop of Zinnias that grow very well in the sandy soil of Kailua. I've figured out the fungus problem and I dead-head almost everyday. I've recently learned about pinching the young to encourage thicker stems, but it's my older plants that I'm concerned about. My first Zinnas are over a year old. They are tall (2-3') and still producing beautiful blooms. My problem/question is, is it possible to encourage growth on the lower part of the plant? They are quite bare and unattractive and yet I'm afraid of cutting them back beyond the leaf growth areas. Will they survive a pruning, or do I need to just plant smaller Zinnias below them?

Thank you in advance for any advise you can give me! Aloha, Xiney Zinnia!