Never tried it and don't have any Garden Patch boxes, but the EB covers are fairly form fitting so if the dimensions aren't within an inch of each other I wouldn't bother.

Covers aren't difficult to improvise with plastic trash bags, plastic rolls (sold as plastic drop cloths in the painting section at hardware stores) etc. Bungie cords, duct tape or whatever suits your fancy to secure them.

The EB covers might be stronger than the GP covers, but I didn't think the EB covers were particularly strong either. I wouldn't spend money on them myself. (note: I haven't seen an EB cover in about 3 or so years so they may have improved them)