Lathyrus latifolius

Sowing and growing guidance

Start Lathyrus latifolius seeds in well-drained, moderately fertile soil and position in full sun to light shade. Sow after last frost; in mild climates, autumn sowing may be possible. Scarify or soak seeds to aid germination, then sow 1–2 cm deep in modules or direct. Keep evenly moist without waterlogging. Transplant or thin to allow good air flow and provide robust support; this tall climbing vine performs best on trellis or netting. Water to establish and during dry spells. Avoid high-nitrogen feeding, which can push foliage at the expense of flowers. Mulch to conserve moisture and suppress weeds, and cut back spent growth to tidy and encourage fresh shoots.

• Suitable for large containers; use a deep pot with a sturdy vertical support.
• Flowers support visiting pollinators.
• Ornamental climber valued for a long, colourful display.
• Nick or soak hard seed coats to speed germination.
• Space plants for airflow and provide strong support to reduce strain and mildew.

How do you grow Lathyrus latifolius from seed?

Lathyrus latifolius seeds have a hard coat, so scarify by lightly nicking the seed opposite the “eye” or rubbing with sandpaper, then soak in lukewarm water for 12–24 hours until swollen. Sow 1–2 cm deep in moist, well-drained mix at 15–20°C; germination typically follows in 10–21 days. Start in modules to avoid root disturbance, or direct sow where they will grow once the soil is workable. Transplant carefully, spacing plants about 30–45 cm apart for good air flow, and install support at planting. Note: seeds and pods are not edible and can be harmful if ingested.

When should I sow perennial sweet pea?

Sow after the last frost when soil is workable and daytime temperatures are settling, or start under cover earlier and harden off before planting out. In mild climates, autumn sowing is possible for earlier growth the following season, provided young plants are sheltered and drainage is excellent. Direct sowing works well where spring is cool and moist; in warmer, drying soils, module-raised seedlings establish more reliably. Avoid very hot spells for sowing, keep the seedbed evenly moist (not waterlogged), and protect emerging seedlings from pests while they establish.

What sun and soil do perennial sweet peas prefer?

Perennial sweet pea thrives in full sun to light shade and in well-drained, moderately fertile soil. Excessive fertility, especially high nitrogen, can produce lush leaves with fewer flowers, so aim for balanced nutrition by incorporating well-rotted organic matter rather than fresh manure. Neutral to slightly alkaline conditions suit it well, and consistent moisture promotes flowering, but the crown dislikes standing water. Mulch to conserve moisture and suppress weeds, and ensure ample air circulation to keep foliage dry after rain or watering.

How tall does Lathyrus latifolius climb, and what support does it need?

This is a tall climbing vine, typically reaching 1.8–3 m in a season once established. It climbs by tendrils, so provide something slender to grasp: sturdy trellis or mesh with 5–10 cm gaps, tensioned wires on a fence, or an obelisk. Supports 1.8–2.4 m high suit most situations; fix them firmly to withstand windy spells and the plant’s weight. Guide new shoots onto the structure and use soft ties until tendrils take over. Allow space at the base for air flow and maintenance, and keep the root area weed-free.

Can perennial sweet pea be grown in containers?

Yes, choose a large, deep container (at least 35–45 cm diameter) with excellent drainage, filled with a high-quality, free-draining mix enriched with organic matter and some grit. Position in full sun to light shade and water regularly to keep the compost evenly moist without saturation. Feed lightly during active growth to maintain flowering, and add a stable support such as a compact trellis or obelisk set into the pot. Containers provide less winter insulation than garden soil, so in regions with severe freezes, protect the root zone from extreme cold.

Does Lathyrus latifolius attract bees and other pollinators?

Yes, the long-lasting flowers are visited by bees and other pollinators, offering reliable forage across the blooming period. While typically less scented than annual sweet peas, perennial sweet pea still produces nectar and pollen and fits well into wildlife-friendly plantings. To extend flowering, remove spent blooms to reduce self-seeding, or leave a few pods if naturalised spread is desired. As with many ornamentals, avoid pesticide use during bloom and provide water nearby to create a more supportive habitat for beneficial insects.

Guidance is compiled from horticultural best practice and supplier documentation. Conditions vary by microclimate, soil structure, fertility, and drainage, so timing and techniques may need adjustment for last frost, soil temperature, and day length. Product pages provide the most specific, up-to-date instructions for each item, including sowing depth, spacing, and indicative timelines. Where applicable, compliance and quality details originate from supplier certifications and testing records noted on the relevant product page.

Perennial Sweet Pea Sowing and Care

Perennial sweet pea, grown from Lathyrus latifolius seeds, is a robust climber suited to sunny, well‑drained positions. For higher germination, gently nick the seed coat or soak for 12–24 hours, then sow 1–2 cm deep in a free‑draining mix. Start indoors 6–8 weeks before the last frost, or direct sow when soil is workable; in mild climates autumn sowing may be possible. Transplant with care to minimise root disturbance, spacing 30–45 cm apart, and provide sturdy support such as a trellis or fence. Keep evenly moist during establishment, then water deeply but infrequently. A balanced, low‑nitrogen feed can be used sparingly if growth is weak. Pinch young tips to encourage branching and remove spent stems to tidy. Flowers are typically unscented compared with annual sweet peas, but provide long‑lasting colour through the warmer months, depending on climate. Avoid waterlogged sites and overly rich fertilisers that favour foliage over bloom.