Greetings, gardener. We are the Lupinus, a genus of striking flowering perennials known for our towering spires of pea-like blossoms. To cultivate us successfully and witness our vibrant display, you must understand our fundamental nature and needs. We are not fragile, but we are particular.
We are sun-worshippers at our core. To thrive and produce our most vibrant flower spires, we require a minimum of six hours of direct, unfiltered sunlight each day. While we can tolerate very light afternoon shade in the hottest zones, insufficient sun will result in weak, leggy growth and few flowers. More critical than almost anything else is our soil requirement. We demand well-draining soil. Our long taproots are designed to seek deep water, but they will quickly rot if left sitting in saturated, heavy clay. Furthermore, we absolutely require slightly acidic to neutral soil (pH 6.0-7.0). We struggle immensely in alkaline soils, a condition that locks away nutrients and leads to our chlorosis—yellowing leaves with green veins.
You can start us from seed, but we present a challenge. Our seeds possess a hard coat that must be compromised for water to penetrate and germination to begin. You must nick the seed coat with a file or soak us in warm water for 24 hours before sowing. Sow us directly in your garden in early spring or autumn, about 1/4 inch deep. Alternatively, you can purchase our young potted forms from a nursery. When transplanting, be exceptionally gentle with our root ball. Disturb our taproot as little as possible, and plant us at the same depth we were growing in our container. Water us deeply immediately after planting to settle the soil around our roots.
Once established, we are moderately drought-tolerant thanks to our taproot. However, for optimal growth and flowering, we prefer consistent moisture, especially during our active growth period in spring and early summer. Water us deeply when the top inch of soil feels dry, but never allow the soil to become soggy. We are light feeders. A generous application of compost at planting time is often sufficient. If you feel the need to fertilize, use a low-nitrogen, phosphorus-rich formula to encourage blooms, not excess leafy growth. Due to the height of our flower spikes, we often require staking, especially in areas prone to wind or heavy rain. Provide support early in the season to avoid damaging our stems later.
To prolong our blooming period and prevent us from channeling energy into seed production, deadhead spent flower spikes by cutting them back to the base of the stem. This may encourage a second, smaller flush of blooms. After our flowering concludes, you can cut the entire plant back to its base foliage to encourage a tidy mound of growth. We are short-lived perennials, typically persisting for 2-5 years. We do not appreciate being divided like other perennials, as our sensitive taproots resent disturbance. The most reliable method for perpetuating our presence in your garden is to allow a few flower spikes to go to seed and self-sow, or to collect and stratify seeds for planting the following season.
