Just add foliage: Thanks to the eco-conscious designers I’ve met and interviewed, I am quite wary of using florist’s foam, a formaldehyde-based product, to stabilize arrangements. Designing around a base of foliage offers a greener way to keep flower stems upright in a vase. Choose leaves that are large, fluffy or textured. Then, insert your other floral ingredients through this vegetation. For example, in this bouquet I placed the heuchera leaves first; then I added the sweet William and mock orange stems. Everything stays just where I want it.