The pods of flowering sweet pea (Lathyrus odoratus) plants are edible only during the early stages of development. Do not eat the pods from sweet-pea vines that have been sprayed with pesticides or other toxic chemicals.
According to North Carolina State University, the seeds, or peas, of the sweet-pea plant are toxic when consumed in large quantities. Pick young sweet-pea pods in the early summer months and soak them in warm water to remove dirt before cooking. Sweet-pea pods can be boiled, steamed or sautéed. The pods of other pea varieties, such as garden peas, snow peas and sugar-snap peas, are also edible.