Large illustration of a n edge pot.
Edge pots create a barrier between the mulch and a seedling or planted seeds, 
which allows the bare soil within the ring pot to warm up more quickly than the surrounding soil covered with mulch.

Warmers soil offers a great advantage in Spring as heat boosts seed germination and promotes seedling growth.  It also offers better protection against snails and slugs as it is easier to apply deterrents such as eggshells to bare ground.