First, how deep do you dig the hole for your compost trench? Generally, it should be about one foot deep (12 inches deep). It ...

Simply dig a 12-inch-deep trench between the rows of vegetables, in the pathway, or in any vacant spot in the garden. Be careful not to damage the plant roots.

If you need to dig a trench, ... Best for Transplanting: Fiskars Steel Garden Spade Shovel; Best for Digging Trenches: Bully Tools 14-Gauge Trench Shovel; What to Consider Type.