Diy Garden Arch Ideas . This vertical trellis works best when it's leaning on something like a fence because the design might not anchor well enough in the ground to stand on its own. Connect these boards together with pocket screws. 15 DIY Arch Designs to Add Height to Your Garden Soil Seed and Garden from soilseedandgarden.com See more ideas about outdoor gardens, garden, garden design. The softer the dirt, the more likely this could be placed in the middle of a garden bed, but you may want to add. Create impact with a series of archways.