Some basic CRF questions for 5-1-1 and Gritty Mix.

I’ve been using Dynamite 18-6-8 All-Purpose CRF, plus Foliage Pro at low strength in my plants for 2 summers, with good results. If I remember right, the Dynamite has everything but zinc, but the FP has the zinc. Plus, from what I’ve read, pine bark does contain some zinc anyway. I’m getting INSANE growth, particularly from tree seedlings (3’ from oaks in a season, 18” on seedgrown Japanese maples) with this method.

I’m running out of my initial supply of Dynamite. So, a few questions:

Initially, I incorporate my CRF into the mix. It seems to last the entire growing season. The following spring, if I’m not at a point where I need to repot the plant, is top dressing the Dynamite CRF sufficient? Or should I at least mix it in a half-inch or so (to not disturb roots too much)?

The largest size Dynamite All-Purpose I can find is the 7lb bag from Seed Ranch. Is there a larger size than this available anywhere?

Has anyone compared side-by-side Dynamite to Osmocote Plus? I avoided Osmocote because the “new” Osmocote Plus isn’t quite as good as the “old” Osmocote Plus, is that correct?