Lupines are the statuesque stalwarts of the cottage-style garden. The tall, vibrant towers bring structure to the flower bed, are beloved by bees and other pollinators, and the perennial varieties offer colorful highpoints year after year.
But there is more to lupines than showy spires in confetti colors; they are legumes (like peas or beans) and they produce vast quantities of seeds, which make delicious high-protein treats to include in cooking – after they have been properly prepared.
Harvesting seeds to reuse from your spent plants and flowers is a greener and cheaper way to garden. In the case of lupines, it is perfect for creating a classic display in your other beds, or sharing them with friends who want some of this candy-box charm. We tell you how to do it to ensure you get the best out of this bounty.
Where did lupines originate?
In spite of their close association with English-style gardens, most varieties of lupines are native to American states including Texas, Florida and Minnesota. Being quick-growing, low-maintenance and self-seeding they rapidly spread in popularity.
Lupines like cooler northern climates but thrive in positions where they get full sun and are in well-draining, slightly acidic soil. They come in a range of shades, but in Texas the state flower is the bluebonnet (Lupinus texensis), which is an annual lupine that covers fields in a sky-colored carpet.
How to harvest lupine seeds
Lupines bloom for around three months from spring to mid-summer, though you can deadhead to encourage a second flowering.
To harvest the seeds, leave the fading flowerheads on the stems to form the pods that will be packed with seeds.
‘When the pods turn brown and dry, that's your sign the seeds are fully mature and ready to harvest,’ says Evan Torchio, a trained arboriculturist. ‘You can even try picking a few green pods early and letting them dry indoors by a window or under a grow light. Whichever method you choose, make sure the final seeds are a deep black or dark color – light-colored ones likely won't sprout.’
You want to make sure that you pick pods that haven’t split open and already released the seeds. Give them a quick shake and you should hear them still rattling inside.
Collecting and storing the seeds
You can open the pods with a thumbnail or small-bladed knife such as this Fiskars harvesting knife from Amazon and lightly brush out the seeds. There can be up to a dozen in there, and with up to 40 pods on a stalk, you'll end up with plenty for your needs and to give to your friends and neighbors.
The lupine plants themselves should be cut back down to the ground, but leave the roots in place as they have rhizomes attached to them that are packed with nitrogen. These are great way to enrich your soil as bacteria will break these rhizomes down, releasing the nitrogen into it.
Once you have collected your seeds, you need to recreate the seasons that they would normally experience outside.
‘If you harvested the seeds directly from the plant in fall, they need a cold spell to mimic winter before they'll germinate well. This is called stratification,’ says Evan.
‘Keep them in the fridge or a cool, dry garage over winter. Then, come spring, you can plant them directly in your garden.’
You could put the seeds in little bags labelled with their color and the date when you harvested them. Stored in an airtight container, they will keep for up to three years.
Harvesting lupine seeds for eating
Lupine seeds are a great source of protein, but also contain bitter-tasting alkaloids that are toxic to humans and animals.
They need to be soaked in salted water for at least 14 days in order to flush the bitter substances out.
So-called sweet lupins are special cultivars that contain little to no trace of these alkaloids. The seeds of the white lupin (Lupinus albus) and the narrow-leafed blue lupin (Lupinus angustifolius) only need to be soaked overnight and boiled for an hour before they are ready for use in salads, stews, burgers or hummus. They can also be ground into flour as an alternative to soybeans.
If you are interested in growing blooms that will give you more than a stunning seasonal display, we have more information on planting flowers with edible seeds here. Sunflowers, poppies and quinoa can all fill your yard with color and your store cupboard with tasty snacks and ingredients.
