Pealike blooms packed onto military-erect stems rising 1 to 2 feet above of large, deeply lobed green leaves can only belong to lupins or lupines (Lupinus spp.), the most architecturally sculpted of all pea (Fabaceae) family plants. Although many lupine species grow in U.S. Department of Agriculture plant hardiness zones 3 through 8, depending on variety, cultivars such as the Russell lupines (Lupinus ployplyllus 'Russell Hybrid'), which grow in USDA zones 4 though 6, are better suited for home gardens. To enjoy their striking display as long as possible, prune lupines regularly.
Pruning Faded Flowers
Start pruning a lupine when about 70 percent of the flowers on its primary stem have died. This technique, known as deadheading, encourages the plant to keep blooming.
Cut the fading stem back to the the first set of leaves, where a new flower stalk may be forming. Use clean, sharp stem cutters.
Before moving on to another stem, wipe the stem cutter blades with a clean rag or towel dipped in rubbing alcohol. This helps prevent spreading diseases.
Continue cutting back the stems as they fade, until the last of them is gone. Then cut the entire plant back to its newest set of basal leaves. If it blooms again, repeat the process.
Pruning Aphid-Infested Plants
Sap-draining aphids frequently overrun lupine stems and leaves. Pruning a plant at the first sign of an infestation may be the only way to save it. Using stem cutters, remove all visibly infested stems and leaves and dispose of them in sealed plastic bags.