How to grow Lupine
When planting lupine from seed in spring, you’ll need to scratch the seed surface or soak seeds overnight in lukewarm (tepid) water to allow the seed coat to be easily penetrated (scarification). Then chill the seeds for a week in the refrigerator in a bag of moist soil prior to planting (stratification). To skip the extra work, just plant lupine seeds in the fall and winter will do the chilling and breaking of the seed coat. Choose an area with lots of sun, good drainage, average soil, and where you would like the flowers to come back year after year, as they will self seed. Lupine is part of the pea family, so it produces nitrogen, and is a great soil amender before planting your late spring and summer garden.
To promote blooming, pinch off spent flowers (this will also prevent early self-seeding). Leave spent flowers at the end of the season to ensure a good crop next year. Because lupine is a nitrogen fixer, the plant can be mowed or tilled directly into your soil (which also starts the scarification process on any left behind seeds)!