Do Sweet Peas Grow Back Every Year?

Sweet peas are a garden favorite, but many gardeners wonder if they can count on them returning year after year. The short answer is that most sweet peas are annuals—they complete their life cycle in one season and do not grow back from the same roots. However, some types are true perennials, and many annual sweet peas will self-seed and appear to come back on their own. Understanding the difference can save you time, disappointment, and a lot of guesswork.

Are Sweet Peas Annual or Perennial?

The sweet peas you typically see in home gardens, with their ruffled petals and strong fragrance, are almost always Lathyrus odoratus, an annual species. These plants sprout, bloom, set seed, and die all within one growing season. They cannot survive freezing temperatures, and the root systems are not designed to regrow the following year.

A separate species, Lathyrus latifolius, is commonly called the perennial sweet pea or everlasting pea. It lacks the strong scent of the annual kind, but it reliably returns from its roots year after year. Many gardeners plant both: annual sweet peas for fragrance and color, perennial sweet peas for long-lasting blooms and low-maintenance ground cover.

So when you ask “Do sweet peas grow back every year?” the correct answer depends entirely on which type you have. If you grew Lathyrus odoratus, the plant itself will not come back. But if you grew Lathyrus latifolius, you can expect it to return each spring.

Do Sweet Peas Come Back Every Year on Their Own?

Even with annual sweet peas, you may see new plants popping up in the same spot the following year. This is not the original plant regrowing—it is self-seeding. Annual sweet peas produce seed pods that, if left on the plant, will dry, burst open, and scatter seeds onto the soil. Those seeds can survive winter in many climates, then germinate when temperatures warm in spring.

Self-seeding is not guaranteed. It depends on soil conditions, winter temperatures, and whether you deadheaded the flowers before pods formed. If you want volunteers, leave a few seed pods on the plant until they turn brown and dry. You can also collect seeds and sow them yourself to ensure a more reliable display.

In contrast, perennial sweet peas spread through underground roots as well as seeds. Once established, they often become vigorous and may even need containment. They do not depend on seed production to return each year.

How Do I Know Which Type I Have?

If you saved the seed packet, look for the botanical name. Lathyrus odoratus is annual. Lathyrus latifolius is perennial. The packet may also say “annual” or “perennial” directly. If you have no packet, check the flower color and fragrance. Annual sweet peas come in many colors—pastels, bicolors, deep purples—and are highly fragrant. Perennial sweet peas usually bloom in pink, white, or purple shades, and they have little to no fragrance.

Another clue is the growth habit. Annual sweet peas are typically climbers that need a trellis, reaching 6 to 8 feet tall. Perennial sweet peas also climb, but they tend to be bushier and spread laterally. If the plant comes back without you doing anything, it is almost certainly a perennial type or an annual that self-seeded heavily.

Can Sweet Peas Survive Winter?

Annual sweet peas are frost-tender. They will die when temperatures drop below freezing, and no amount of mulching will keep the roots alive. In mild climates where frost is rare, they may persist through winter, but they will still decline as they complete their life cycle. To enjoy them again, you need new seeds.

Perennial sweet peas are hardy in USDA zones 4 through 8 or sometimes colder, depending on the variety. They die back to the ground in winter but send up new shoots from the roots in spring. Mulching around the crown can protect them in colder zones, but they are generally tough and need little help.

If you live in a very cold climate and want sweet peas that return, perennial types are the better choice. In warmer areas where winters are mild, annuals can be planted in fall for winter blooms, but they still will not regrow from the same plant after the second year.

How to Help Sweet Peas Return Year After Year

For annual sweet peas, the only way to have them return is through seeds. You have two options:

1. Let some plants go to seed in late summer and allow natural self-sowing.
2. Collect seeds after the pods turn brown and store them in a cool, dry place. Sow them the following spring or fall, depending on your climate.

For perennial sweet peas, encourage return by providing proper care:

• Cut back dead stems in late winter or early spring before new growth emerges.
• Apply a thin layer of compost or balanced fertilizer around the base in early spring.
• Water during dry spells, especially in the first year after planting.
• Avoid disturbing the root zone—perennial sweet peas form deep taproots and resent transplanting.

A common mistake is cutting back perennial sweet peas too early in fall. Wait until the foliage has died back naturally. Also, do not overwater in winter; soggy soil can rot the roots.

What Are Perennial Sweet Peas and Should I Grow Them?

Perennial sweet peas (Lathyrus latifolius) are not the same as the fragrant annuals, but they have their own strengths. They are vigorous climbers that can cover fences, arbors, or unsightly structures. They bloom from early summer until frost and produce showy sprays of pink, white, or purple flowers. They are also more drought-tolerant once established.

The main trade-off is fragrance. If scent is your priority, stick with annual sweet peas. If you want a reliable, low-effort climber that returns every year without replanting, the perennial sweet pea is an excellent choice.

There is also a lesser-known true perennial called Lathyrus tuberosus, or earthnut pea, but it is harder to find and grown more for its edible tubers than for cut flowers. For most home gardeners, Lathyrus latifolius is the only practical perennial option.

Common Mistakes That Prevent Sweet Peas from Returning

Even when you choose the right type, simple errors can stop sweet peas from coming back. Here are the most frequent ones:

• Deadheading all flowers. Removing every spent bloom prevents seed pod formation. If you want self-seeding annuals, leave at least a few pods to mature.
• Cutting down too early. Perennial sweet peas need their foliage to die back naturally. Cutting green stems forces the plant to use stored energy to regrow, weakening it.
• Planting in the wrong zone. Perennial sweet peas may not survive in very hot or very cold climates. Check your USDA zone before buying.
• Over-fertilizing. Too much nitrogen encourages leaves at the expense of flowers and reduces seed production.
• Ignoring pests. Aphids and slugs can weaken plants and reduce seed set. Control them early.

When and How to Plant Sweet Peas for Continued Blooms

Timing matters, especially if you want a recurring patch. For annual sweet peas:

• In cold climates (zones 6 and below): Sow seeds indoors 4 to 6 weeks before the last frost. Harden off and transplant after danger of frost passes. For fall self-seeding, allow some pods to mature in late summer.
• In mild climates (zones 7–10): Sow seeds directly in fall for winter and spring blooms. Let plants set seed in spring, then die back in summer heat. New seeds will germinate when cool fall weather returns.

For perennial sweet peas:

• Spring planting: Start seeds indoors or buy nursery plants. Set them out after the last frost. They may not bloom heavily the first year, but they will establish roots.
• Fall planting: In mild climates, fall planting works well. Give them a month to root before the first hard frost.

Soak annual and perennial sweet pea seeds overnight before planting to speed germination. Nick the seed coat with a nail file if they still seem hard.

Quick Care Checklist for Sweet Peas

Recommended Tools for Sweet Pea Growing

Growing sweet peas successfully is easier with the right gear. A seed starting tray with a humidity dome helps germinate annual sweet peas indoors before the season starts. You can find seed starting trays online.

For supports, bamboo canes and garden netting work well for both annual and perennial climbers. A cane support ring keeps stems tidy.

Pruning shears are necessary for cutting flowers and removing dead growth. Look for bypass pruners that make clean cuts. They help extend the bloom season on annuals and keep perennials healthy.

A balanced organic fertilizer, such as a 5-10-10 formula, supports flower production without pushing excessive foliage. Organic flower fertilizer is a good choice.

Frequently Asked Questions About Sweet Pea Growth Cycles

Will sweet peas survive in pots and come back? Annual sweet peas in containers will not return—the roots freeze or the plant exhausts itself. Perennial sweet peas can survive in large pots in mild climates if protected from hard freezes, but they do better in the ground.

Can I overwinter sweet pea seedlings indoors? Yes, you can start seeds in late fall, grow them under lights, and transplant them after the last frost. Those plants will still be annuals and die after flowering.

Do deer or rabbits eat sweet peas? Deer usually avoid sweet peas because the plants contain compounds that taste bitter. Rabbits may nibble young shoots. Protection may be needed in high-pressure areas.

Why did my sweet peas bloom the first year but not the second? If you planted annual sweet peas, that is normal. If you planted perennials, the issue might be too much shade, poor soil, or excessive nitrogen.

The Bottom Line on Sweet Peas and Yearly Growth

Knowing whether sweet peas grow back every year comes down to one simple distinction: annual vs. perennial. Most fragrant sweet peas are annuals, and their beauty lasts only one season unless you save seeds or let them self-sow. Perennial sweet peas, though less fragrant, will return reliably from their roots and give you years of low-maintenance color. If you want both fragrance and reliability, plant annual sweet peas for cutting and perennial sweet peas for a permanent garden feature. Whichever type you choose, understanding their growth cycle will help you plan, enjoy more blooms, and avoid the disappointment of wondering why they did not come back.

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