As the growing season picks up a pace, Monty is sowing vegetables and planting out the scented plants which he brought back from the Malvern Spring Festival. Carol is delving into the hedgerows and rooting at the bases of walls, fences and trees as she begins her journey to investigate why plants thrive in challenging conditions and we return to Sissinghurst to find out about the changes Troy Scott-Smith is making to the world famous white garden.

This week we are celebrating the work of the army of volunteers who keep gardens up and down the country looking their best for visitors. Frances Tophill continues her vegetable trials at RHS Rosemoor in Devon when she plants out her allotment with the help of RHS volunteers and we visit the Bodnant Garden in north Wales to find out how the volunteers there guide visitors through the world-famous Laburnum Arch. Back at Longmeadow, we catch up with Monty's progress in his cutting garden and, now that plants are growing apace, he gets on with seasonal maintenance tasks in the Jewel Garden.