Makeshift Raised Flower Bed over concrete: Does it need drainage holes? Will it waterlog my plants?
It is essentially a wooden box (or a chest) with soil in it out on my concrete patio. I added a plastic tarp to the bottom, which I am now thinking is a mistake (I just learned that roots can get waterlogged and kill the plant). I already put all my soil and flowers in, and I'm not sure what to do. Thoughts?
Certified GKH Gardening Expert
Yes it needs drainage. The best of course is if you can pull everything out and start over with holes in the bottom, no tarp and raise the box a little with some wood or bricks underneath.
But the shortcut would be to drill some holes along the lower edge of the wooden box, where the bottom of the soil level is? Although if the tarp comes up on the sides, inside the box you would have to drill the holes clear through the tarp also, and that could be a complication.
Another option is to not water anymore than you have to. Just moisten enough to keep the plants alive but not so much as to waterlog the soil.