Lathyrus latifolius aka Everlasting Pea

Lathyrus latifolius is a vine that lives for many years. It belongs to the pea family. Its names include everlasting pea and perennial pea. It comes from east-central Europe, southern Europe, and northwest Africa. Garden plants have spread through much of the United States and Canada. It grows by roads, fences, and fields, and on disturbed ground. Some areas class it as invasive. It spreads through rhizomes, or stems that grow below ground. It can also spread by setting many seeds.

This vine grows fast and climbs with tendrils. These thin parts grip supports, or the vine sprawls across the ground. Garden height ranges from about 5–9 feet [1.5–2.74 metres]. North Carolina State reports heights of up to 10 feet [3 metres]. Sources give a spread of 1.6–6 feet [0.5–1.83 metres]. The green stems have broad wings shaped like leaves along their sides. Leaflets grow in pairs and are oval to oblong. Their colour ranges from green to grey-green. Each leaf ends in a tendril that grips nearby supports. Leaves fall, and growth dies back in winter.

Pea-shaped flowers grow on long stalks above the leaves. They form racemes, with blooms spaced along a main stalk. Flowers are pink, purplish-pink, or white, about one inch across. They bloom from June through September and draw butterflies. You can cut them to display indoors. Flat, narrow pods follow the blooms and hold round green seeds. The vine can cover fences, walls, banks, and rocky ground. It suits borders, cottage gardens, and pots. As ground cover, its strong growth can crowd smaller plants.

Give it full sun or light shade and rich soil that drains well. It accepts clay, chalk, loam, and sand across a broad pH range. For best growth, keep the soil moist throughout, but not unevenly wet. Plants that have taken root can cope with drought. They prefer cool soil and cool summers. Give it good air flow; avoid watering from above. Sources list USDA zones 3–8 and UK hardiness H7. Cut stems to ground level in autumn. Slugs, snails, aphids, pea moths, and mites may harm it. Diseases may include mildew, rust, grey mould, wilt, and leaf spot. Sources report no serious pest or disease problems as a rule.

Sources disagree on eating this plant, so treat food claims with care. PFAF lists cooked seeds, young pods, and young growth as edible. RHS says not to eat the pods or seeds. North Carolina State warns that large meals of seeds can cause severe poisoning. ASPCA lists it as toxic to horses, but not dogs or cats. Signs of poisoning include weakness, tremors, seizures, and possible death. PFAF records no known use as medicine.