Producing daisy-like flowers in shades of pink, white, and red, cosmos are another great cutting flower, say the O'Neals. "Their blooms are incredibly delicate and add the sparkle element to a bouquet," they say.

While they need full sun and typically grow in the 32- to 48-inch range, cosmos can be kept at a shorter length when they are pinched at 18 inches (this promotes branching!). "Cut blooms from them regularly, or remove old blooms to promote flowering," say the O'Neals. "Cosmos should be cut when the first petal is just beginning to curl open to give them the maximum vase life."