We bought a house last year that has an established "butterfly garden". What do I add to the soil to enrich it. The only source I have is home depot, so please, nothing too exotic. In about 2 weeks, I will want to start planting in it, primarily, some annuals to fill in the gaps. I have seeds for zinnias and cosmos and a few other things.

I am just thinking that I need to top dress with something before summer. The soil is in decent shape. One section has some clay in it that I need to do something about.

Thanks for your time. I would really like for it to have a good start this year.

Paula