Are Sweet Peas Perennials? Understanding the Life Cycle of Sweet Peas

Sweet peas (Lathyrus odoratus) are a garden favorite, admired for their fragrance, delicate petals, and colorful blooms. Many gardeners wonder: Are sweet peas perennials, or do they need to be replanted every year?

The answer depends on the variety. While most sweet peas are annuals, there are perennial sweet pea varieties that return year after year.

In this guide, you’ll learn:

✔️ The difference between annual and perennial sweet peas
✔️ How to grow and care for both types
✔️ Pros and cons of perennial sweet peas
✔️ Best varieties for UK gardens

Let’s explore whether sweet peas are perennials or annuals! 🌿🌸

1. Are Sweet Peas Perennials or Annuals?

There are two types of sweet peas:

1. Annual Sweet Peas (Lathyrus odoratus) 🌸

✔️ Most common type—needs replanting each year.
✔️ Grows fast from seed, blooms all summer, then dies after flowering.
✔️ Produces strong fragrance and larger flowers.
✔️ Popular varieties: ‘Cupani’, ‘Spencer Mix’, ‘Old-Fashioned Mix’.

2. Perennial Sweet Peas (Lathyrus latifolius) 🌿

✔️ Comes back every year—long-lived, hardy plant.
✔️ Produces smaller, less fragrant flowers but vigorous growth.
✔️ Can become invasive if not managed properly.
✔️ Popular varieties: ‘Everlasting Pea’, ‘Red Pearl’, ‘White Pearl’.

Key Difference: Annual sweet peas have a stronger scent and larger blooms, while perennial sweet peas are hardier but have smaller, less fragrant flowers.

2. What Are Perennial Sweet Peas?

Perennial sweet peas (Lathyrus latifolius) are also called Everlasting Peas.

Characteristics of Perennial Sweet Peas

🌿 Long-lived – Grows back every spring from the same root system.
🌸 Climbing habit – Can grow up to 2m (6ft) tall.
☀️ Hardy & low-maintenance – Tolerates frost and drought.
⚠️ Less fragrance – Unlike annual sweet peas, they lack strong scent.
💜 Flowers in pink, purple, and white – Attractive but not as showy as annual varieties.

Tip: Perennial sweet peas are great for wild gardens, fences, and trellises but require management to prevent spreading.

3. How to Grow Perennial Sweet Peas

Best Time to Plant

✔️ Spring (March–May) – Ideal for sowing directly outdoors.
✔️ Autumn (September–October) – Can be started in a greenhouse for early growth next year.

Planting Guide

✔️ Choose a sunny or partially shaded spot.
✔️ Ensure well-draining soil—they tolerate poor soil conditions.
✔️ Sow seeds 2–3 cm deep in prepared beds or containers.
✔️ Water lightly until established, then reduce watering.

Training & Support

✔️ Use trellises, fences, or garden obelisks for climbing support.
✔️ Tie stems loosely as they grow.

Pruning & Maintenance

✔️ Cut back dead stems in autumn for tidier growth.
✔️ Remove seed pods to prevent self-seeding (they can spread aggressively).

Tip: If left unchecked, perennial sweet peas can become invasive, so prune regularly.

4. How to Grow Annual Sweet Peas for a Single Season

🌿 Sow seeds indoors (Jan–March) or directly outdoors (April–May).
🌸 Provide full sun and rich, well-draining soil.
🌿 Pinch out growing tips when 10 cm tall for bushier growth.
🌸 Deadhead flowers regularly to extend blooming season.
🌿 Support with canes, trellises, or netting for climbing.

Tip: Annual sweet peas bloom longer and have stronger fragrance than perennials.

5. Pros & Cons of Perennial Sweet Peas

Tip: If you love fragrance and showy flowers, stick to annual sweet peas. If you want low-maintenance climbers, choose perennial sweet peas.

6. Best Sweet Pea Varieties to Grow

Best Annual Sweet Peas (Highly Fragrant)

🌸 ‘Cupani’ – Old-fashioned variety, rich purple and maroon flowers.
🌿 ‘Spencer Mix’ – Large blooms, great for cut flowers.
🌸 ‘Royal Family’ – Vigorous climber, long flowering season.

Best Perennial Sweet Peas (Long-Lasting & Hardy)

🌿 ‘Everlasting Pea’ (Lathyrus latifolius) – Hardy, pink/magenta flowers.
🌸 ‘White Pearl’ – Pure white flowers, vigorous growth.
🌿 ‘Red Pearl’ – Striking deep pink-red blooms.

Tip: For longest-lasting displays, mix annual sweet peas for fragrance with perennial sweet peas for year-after-year growth.

7. Final Thoughts: Are Sweet Peas Perennials?

✔️ Most sweet peas are annuals and need replanting each year.
✔️ Perennial sweet peas (Everlasting Peas) return every year, but lack fragrance.
✔️ Annual sweet peas produce bigger, more fragrant flowers but die after one season.
✔️ Perennial sweet peas are great for covering fences & walls but need pruning to control spreading.
✔️ Both types can be grown together for fragrance and long-term color in the garden.

Sweet peas—whether annual or perennial—bring beauty and charm to any outdoor space! 🌿🌸

Now you know the difference between annual and perennial sweet peas! 🌿💜 Let me know if you have any questions! 🚀