The magical, old-fashioned sweet pea (Lathyrus odoratus) has graced even the very formal gardens for centuries. Endowed with the heady scent of orange honey and flowers, this pretty annual displays one of the very extensive flower color ranges among all plants. Long-lasting early spring blooms display solids, streaks, flakes and bi-colors in vivid reds, pinks, blues, lavenders and white whites like bulb flowers fade. Anyone in North America can readily grow sweet peas. The seeds are large and simple to collect when summertime heat chases the plants in the garden to the season.
Deadhead sweet pea plants to extend the blooming season. Snip off blossoms after they fade to maintain vines looking tidy. This may encourage the plant to direct its energies toward continued flowering rather than seed production. Deadheading will also remove excessive numbers of seed pods. This plant reseeds itself prolifically.
Leave a few dead flowers on each and every vine for seed collection. When the sweet pea blossom falls its petals, a seed pod begins to form. The green pods will begin to turn brown as they mature.
Monitor seed pods daily once they turn brown. Squeeze a pod. It’ll feel brittle and begin to break when the seeds are older and ready for harvest. Should you wait any longer, the forks will burst open and scatter the seeds. Pick the pod and drop it into a brown paper bag. Close the bag tightly.
Establish the closed paper bag on a warm windowsill. Pick it up and shake it vigorously each day till the sweet pea seeds explode out of the pod.
Pick the seeds out of the debris. Seal them in a paper envelope, and label it with the date and variety. Store the envelope in the refrigerator crisper drawer till you are ready to plant.