Are sweet pea vines perennial? The short answer is no—most sweet pea varieties (Lathyrus odoratus) are annuals. They complete their entire life cycle in one growing season and die after frost. However, a close relative called the everlasting pea (Lathyrus latifolius) is a true perennial that returns year after year, but it lacks the famous fragrance.
What does "perennial" mean for sweet pea vines?
A
perennial plant lives for more than two years. Perennials die back to the ground in winter and regrow from the same root system each spring. An
annual plant, on the other hand, finishes its entire life cycle—from seed to flower to seed—in one season and then dies. Most sweet pea vines are annuals. They sprout, bloom, set seed, and die within a single year. Gardeners often treat them as annuals because they cannot survive cold winters.
Are there any perennial sweet pea varieties?
Yes, but they are not the same as the classic fragrant sweet pea. The
everlasting pea (Lathyrus latifolius) is a true perennial vine. It produces pink, red, or white flowers, but it has
no scent. Many gardeners grow it for its long bloom time and ability to cover fences. Everlasting peas are hardy in USDA zones 4 to 8. They need full sun and well-drained soil, just like annual sweet peas. If you want fragrance, stick with annual sweet peas.
Can sweet pea vines survive winter?
Annual sweet pea vines
cannot survive frost. They are tender plants that die as soon as temperatures drop below freezing. In mild climates where winter temperatures stay above freezing, they might act like short-lived perennials, but that is rare. The everlasting pea survives winter because its roots go dormant underground. In cold climates, annual sweet peas must be replanted from seed each spring.
How do I grow sweet peas as annuals?
Growing sweet peas as annuals is simple. Start seeds indoors 4 to 6 weeks before the last frost date. Soak seeds overnight to speed germination. Plant them in rich, well-drained soil in full sun. Provide a
strong trellis or support because sweet peas are climbing vines. Keep the soil evenly moist, and deadhead spent flowers to extend blooming. They thrive in cool spring weather but fade in summer heat.
What about the everlasting pea (Lathyrus latifolius)?
The everlasting pea is a
reliable perennial for gardeners who want repeat blooms. It spreads by underground rhizomes, so it can become invasive. It does not need staking as much as annual sweet peas, but a trellis helps. It flowers from early summer to fall. Unlike annual sweet peas, it
requires no deadheading to keep blooming. However, it has no fragrance. If scent is important, plant annual varieties like 'Cupani' or 'Old Spice'.
How to tell if your sweet pea is annual or perennial?
Check the scientific name on the seed packet or plant tag.
Lathyrus odoratus means annual sweet pea.
Lathyrus latifolius means perennial everlasting pea. Annual sweet peas have larger, more fragrant flowers in a wider color range. Perennial everlasting peas have smaller, unscented flowers in pink, red, or white. Also, annuals die after one season; perennials return.
When should I plant sweet pea seeds?
For annual sweet peas, plant seeds as soon as the soil can be worked in early spring. In mild-winter areas, you can sow in fall for winter bloom. For perennial everlasting peas, plant seeds in spring or fall. They need a period of cold to germinate well. You can also
start seeds indoors 4 to 6 weeks before planting outside.
What care do sweet pea vines need?
Sweet peas need
consistent moisture, especially when blooming. Apply a layer of mulch to keep roots cool. Feed with a balanced fertilizer every 2 weeks. Pinch out the growing tip when plants are 6 inches tall to encourage bushiness. Provide a trellis, fence, or netting for climbing. Watch for pests like aphids and powdery mildew.
Here is a simple care checklist for sweet pea vines:
| Care Task |
Annual Sweet Pea |
Everlasting Pea (Perennial) |
| Sun |
Full sun |
Full sun |
| Soil |
Rich, well-drained |
Well-drained, tolerates poor soil |
| Water |
Regular, 1 inch per week |
Moderate once established |
| Support |
Needed (trellis or netting) |
Helpful but not required |
| Deadheading |
Yes, to prolong bloom |
Not needed |
| Winter survival |
Dies with frost |
Comes back in spring |
Do sweet peas come back every year?
Annual sweet peas
do not come back from the root. They drop seeds that may sprout the next year if conditions are right. But you cannot rely on self-seeding. Perennial everlasting peas
do return year after year from the root system. If you want a low-maintenance return, choose everlasting pea. If you want fragrance and variety, plan to replant annuals each season.
Where can I buy sweet pea seeds and vines?
You can find sweet pea seeds at garden centers, online seed catalogs, and large retailers. Look for
high-quality seeds from reputable brands. For annual sweet peas, try a mix like 'Old Spice' or 'Cupani'. For perennial everlasting peas, look for 'Pink Pearl' or 'Red Pearl'. A sturdy trellis is also essential. You might consider a
sweet pea seed mix for variety, or a
metal trellis to support the vines. Some gardeners also use
balanced flower fertilizer to boost blooms.
