What Can Help With Too Much Moisture in a Pond Turned Flower Garden?
I recently filled in a concrete based (approx 12Lx8Wx4 ft deep) pond in and tried to make it a flower garden. Now I fear I have too much moisture as my flowers have black spots on their leaves and moss is growing on the mulch. We started by filling in with about 3 ft of good fill soil, half a foot of good gardening/planting soil and a couple inches of mulch. We have had a lot of rain. It's impossible at this point to dig it up and drill drain holes in the concrete, so is there anything else I can do or plant that will help with too much moisture? Thanks
Possibly a bog garden. check out this article: https://www.gardeningknowhow.com/special/spaces/designing-bog-gardens.htm
Another alternative might be a Corkscrew Willow. You could add some hosta and ferns.