I always put it in the hole when I planted them, I never side dressed with it. I think the best time to fertilize the re-bloomers is right after they are done blooming, it's a bit late now, and excessive late new growth can be very tender over winter. I think a regular balanced fertilizer like 10 10 10 would be best, but Arlyn is the re-bloomer in the group.
better ask him.
