How to Grow Sweet Pea
Wikimedia Commons
Sweet Pea
Lathyrus odoratus
flowerSweet peas are delicate, fragrant climbing or bushy flowering plants prized for their colorful, ruffled blooms and intoxicating perfume. They produce long stems ideal for cutting and flower arrangements. Available in numerous color varieties, sweet peas are popular ornamental garden plants that bloom profusely in cool seasons.
Looking for a specific variety?
When should you plant Sweet Pea in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Sweet Pea timeline · Pittsburgh, PA (Zone 6b)
-
Plant Sweet Pea
Around Apr 17Near Pittsburgh's average last spring frost.
-
Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
-
First Sweet Pea blooms
Around Jun 16≈ 60 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Sweet Pea dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 2-9; can be grown as cool-season annuals in warmer zones
Sign up free to see if Sweet Pea grows in your zone — and get a personalized planting timeline.
Get my Sweet Pea timeline →Growth Stages
Germination
7-14 daysSeeds sprout and develop first true leaves; tender seedlings emerge from soil
Soak seeds 24 hours before planting to improve germination. Keep soil moist but not waterlogged. Provide cool conditions (60-70°F). Thin seedlings if needed.
Vegetative Growth
3-4 weeksPlant develops sturdy stems, multiple leaves, and climbing tendrils (if vining type); bushy growth habit
Install support structures (trellises, stakes, netting) early for climbing varieties. Pinch out growing tips on bushy types to encourage branching. Water consistently and mulch around base.
Budding & Early Bloom
2-3 weeksFlower buds form along stems; first flowers begin to open in characteristic ruffled form
Deadhead spent flowers regularly to extend blooming. Reduce nitrogen fertilizer to encourage more flowers than foliage. Stake climbing varieties securely.
Peak Flowering
4-8 weeksPlant produces abundant, colorful, fragrant flowers; continuous blooming if conditions remain cool
Cut flowers frequently for arrangements to promote more blooms. Water during dry spells. Monitor for pests and diseases. Avoid high heat and humidity.
Late Season / Decline
Variable by season and climateFlowering slows as temperatures rise or frost approaches; seed pods develop if flowers not harvested
In cool climates, plants may rebound with cooler fall weather. Allow some flowers to set seed if desired for self-sowing next year. Remove plants after heavy frost.
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
-
Spray with insecticidal soap or strong water stream. Introduce ladybugs. Use neem oil as needed.
-
Increase humidity and spray with water. Use miticide if severe. Remove heavily infested leaves.
-
Remove affected flowers. Use sticky traps. Spray with spinosad or insecticidal soap.
-
Ensure good air circulation. Spray with fungicidal sulfur or baking soda solution. Remove infected foliage.
-
Improve drainage. Avoid overwatering. Use well-draining soil. Remove severely affected plants.
Uses
Edible Flowers for Decoration
CulinarySweet pea flowers are non-toxic and can be used to garnish salads, desserts, and cocktails for elegant visual appeal and delicate flavor. Ensure they are pesticide-free and grown specifically for culinary use. [source]
Cut Flower Arrangements
HouseholdSweet peas are prized for floral arrangements due to their long stems, delicate ruffled blooms, and exceptional fragrance. They are a classic choice for bridal bouquets and formal flower displays. [source]
Pressed Flowers & Craft Projects
CraftThe delicate petals press beautifully for use in scrapbooking, bookmarks, greeting cards, and decorative crafts, preserving their color and form. [source]
Natural Fragrance
HouseholdThe sweet, intoxicating scent of fresh sweet pea flowers naturally perfumes gardens and indoor spaces. A few stems in a vase can fragrance an entire room. [source]
Pollinator Support
WildlifeSweet pea flowers attract bees, butterflies, and other pollinators, supporting garden biodiversity and contributing to local ecosystem health. [source]
Harvest Tips
Cut flowers in early morning when blooms are fully open and stems are hydrated. Use sharp scissors or secateurs and cut just above a leaf node. Remove lower leaves below the water line. Change water every 2-3 days and recut stems. Cut regularly to encourage continuous blooming throughout the season.
Fun Facts
- 🌱 Sweet peas have been beloved in gardens for over 300 years; they were first brought to Europe from Sicily in the 17th century and became Victorian England's favorite cut flower.
- 🌱 Gregor Mendel, the father of modern genetics, used sweet peas in his groundbreaking experiments on heredity and plant breeding in the 1860s.
- 🌱 Sweet peas climb using delicate tendrils that coil around supports; they can reach heights of 3-6 feet depending on variety, with some cultivars growing much taller if given support.
Gardening Terms
New to gardening? Learn about terms used in this guide:
Join 30,000 gardeners planning their gardens with LizPlants.
Get your personalized Sweet Pea planting timeline
Tell us your zip code and we'll calculate exactly when to start Sweet Pea seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.
Get my Sweet Pea timeline →