In the world of Ralph Lauren, all Pea-family plant seedlings grow up to be lupines. Decked with tall, slender flower spikes in stylish shades of purple, blue, magenta, yellow, pink and white, lupines add haute-couture flair to spring and summer gardens in U.S. Department of Agriculture plant hardiness zones 3 through 8, depending on variety.
Wildflower lupine species (Lupinus spp.) typically struggle in cultivation. Much better choices for home gardens in USDA zones 4 through 6 are the Russell hybrid cultivars (Lupinus polyphyllus 'Russell Hybrids').
Because lupines rarely survive more than four years, many gardeners collect and save the seeds of their favorite varieties for future planting. The key to success lies in timing the harvest before the seedpods burst and cast their contents to the winds.
A lupine's faded flowers give way to hairy, green cigar-shaped seedpods, each with several seeds. When the pod casings turn greyish green and their dark-brown seeds are visible when held up to the light, it's time to harvest. If you're saving seeds from more than one lupine variety, label the bags.
Instead of collecting individual pods, cut the entire stalks from the plants and place them in closed paper bags.
Place the bags in a warm, dry area and check them periodically. When the pods are black and crack easily -- usually within a month -- remove the ripe seeds and put them in labeled paper envelopes for storage.
Seal the envelopes in airtight jars before storing them in a cool, dark place until you're ready to plant them. An unheated potting shed, garage or cellar is a good choice.