A great climber that’s perfect for fences and trellises! Home flower gardeners are growing sweet peas (Lathyrus odoratus) for their tantalizing fragrance and award-winning blossoms. Easy to start from seed, they add soft, varied color to bouquets and trellised borders.
A classic, cool-season annual, sweet pea flowers have been a fixture in American gardens for generations. However, they don’t like heat — hot weather stops their flowering — so plant very early and mulch well to keep roots cool.
This hardy annual is one of the very first seeds that can be planted in the ground, 4-6 weeks before your last frost date. A few perennial sweet pea varieties are available, but they have no fragrance and will only bloom in whites and pinks.
Fun fact. Sweet peas are so popular in my hometown of Bozeman, Montana that we have a three-day art festival named after them.
Sweet Pea Seeds
Uniquely shaped and sweetly fragrant, sweet pea blossoms add color to summer gardens.View all
Tired of the same old daisies? These heirloom flower seeds will brighten any landscape. Planting instructions are included with each packet and shipping is FREE!
Quick Guide: Planting, Growing & Caring for Sweet Peas
- Select your favorite color: pink, blue, purple, red and more
- Direct seed in very early spring, as soon as soil can be worked
- Plant in full sun and soil amended with compost or organic matter
- Water regularly; plants will slow growth in hot weather
- Pests and diseases include aphids, slugs and powdery mildew
Sunlight: Full sun
Maturity: 55-75 days from seed to flower
Height: 48 to 72 inches
Spacing: 4 to 6 inches apart in all directions
Sweet peas like a rich, well-drained soil but will tolerate various conditions. Soak seeds before planting to improve germination. Sow directly into the soil, about 4-6 inches apart and cover with 1/2 inch of soil.
How to Plant
Sow sweet pea seeds early, as soon as the soil can be worked in early spring. Seed casings are hard, so soak overnight for best germination. Plants like full sun and cool weather.
Water regularly during dry conditions to keep flowers blooming. Fertilize a couple times during the gardening season with an organic flower fertilizer designed for abundant blooms.
Vining sweet peas (the majority) need a support to climb, so provide them some sort of trellis. Once the vines begin blooming, cut the flowers and bring them inside to enjoy. The more you cut, the more flowers will grow.
As the weather begins to warm, flower production will slow. When flower production stops and the vines begin to dry, chop the foliage and turn it into the existing soil as a free source of organic nitrogen. Keep in mind that sweet peas, though an annual, will reseed and appear again the following spring.
For more tips on creating a gorgeous flower displays, watch our 6 Tips for Great Flowers video.
Tip: Long-time gardeners in New England often plant sweet peas around St. Patrick’s Day.
Insect & Disease Problems
Large irregular holes in foliage and partially eaten seedlings are signs of slug damage. Scatter Sluggo®, an organic iron phosphate bait, around plants to kill slugs and snails without harming people, pets or wildlife.
In wet, cool weather mildew and plant diseases abound. If wilting, spots or rotted tissue are noticed, we recommend the following:
- Avoid overhead watering whenever possible (use soaker hoses or drip irrigation)
- Properly space plants to improve air circulation
- Apply copper spray or sulfur dust to prevent further infection
Note: Sweet peas are popular with ladybugs and green lacewings. Grow them in and around your vegetable gardens to attract these pest-eating beneficial insects.
Seed Saving Instructions
Plants should be separated by 25 feet to ensure absolute purity. Wait for the pods to dry before picking. Seed pods will burst, so picking in a timely manner is critical. Read our article on Saving Heirloom Flower Seeds to learn more.
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