HelpfulGardener.com

Peonies? The package did not indicate Peonies on the list, but it says it's safe for flowers and roses?

Miracle gro plant food generally tends to have salts in them, which pretty much kills your soil and makes you dependent on Miracle Gro for feeding them. That said, I haven't seen the ingredients in that specific product, so I can't say with certainty if it is safe to use. But rule of thumb is usually to stay away from Miracle Gro type products.