Drainage of Elevated Garden Bed

Asked May 4, 2020, 11:55 AM EDT

our senior community has provided elevated garden beds, What drainage is appropriate for a 2ft x 4ft elevated garden bed? the beds are lined with black landscape tarp, there isabout 1/4 inch space between floor and end side boards. should i drill more drainage holes, what diameter, how many? does water penetrte the tarp?

Montgomery County Maryland

1 Response

Hi- water will pass through the landscape fabric and between the end boards and floor- even if the beds are sitting on an impervious surface like macadam.

If the floor is solid and continuous (e.g. plywood) it would be prudent to drill 10-12 holes, 1/4 inch to 1/2 inch in diameter, to facilitate drainage.
https://extension.umd.edu/hgic/topics/raised-beds
Jon