Sweet Peas Are Easy to Grow from Seeds When You Follow These Tips
Sweet peas are gardener's favorites because of their fragrant, delicate blooms that climb beautifully on trellises, fences, and arches. This flowering plant thrives in cooler climates and adds vibrant colors and a lovely scent to any garden. Sweet pea vines can grow quickly with proper care, making them a perfect choice for vertical gardening.
Choosing a Variety of Sweet Pea
There are numerous varieties of sweet pea to choose from, each with unique traits:
Heirloom Sweet Peas: Known for their strong fragrance and delicate flowers, heirloom varieties are perfect if you want a garden filled with rich scents. These varieties typically feature soft pastel blooms.
Spencer Sweet Peas: With larger blooms and ruffled petals, Spencer sweet peas are ideal for cut flowers and floral arrangements. They offer a wide range of vibrant colors.
Dwarf Sweet Peas: For gardeners with limited space, dwarf varieties, such as ‘Cupid’, are compact and bushy, growing up to 10-12 inches tall, making them perfect for containers or small gardens.
When to Start Sweet Pea Seeds
For best results, sow sweet pea seeds indoors 6-8 weeks before the last frost date in your region. Sweet peas are cool-weather plants, so it’s important to give them an early start indoors to ensure strong, healthy growth when transplanting outside. In milder climates, sweet pea seeds can be sown directly into the garden in late winter or early spring.
How to Start Sweet Pea Seeds
Before planting, sweet pea seeds benefit from pre-treatment. Soak the seeds in water for 24 hours or gently nick the seed coat with a nail file to encourage faster germination. Plant seeds in your indoor seed starting medium or individual pots filled with a well-draining seed-starting mix, about 1 inch deep. Place the pots in a cool, bright area. Sweet peas prefer cooler temperatures for germination, which can take 10-14 days.
Transplanting Sweet Peas
Once the sweet pea seedlings have grown to about 4-6 inches tall, and the threat of frost has passed, they are ready for transplanting. Sweet peas are cold-tolerant but need to be hardened off by gradually exposing them to outdoor conditions for a week before planting. Choose a sunny spot with well-drained soil and space the plants about 6-8 inches apart. Sweet peas are climbers, so be sure to provide a support structure like a trellis or netting for the vines to climb.
Special Considerations: Annual or Perennial Sweet Peas
Most sweet peas are annuals, blooming in the spring and early summer before dying back. However, there are perennial varieties, such as Lathyrus latifolius (commonly called Everlasting Pea), which will return year after year in USDA zones 4-7. Keep in mind that perennial sweet peas lack the signature fragrance that annual varieties are known for, but they offer consistent blooms year after year.
Growing Tips for Sweet Pea
For a flourishing sweet pea display:
- Pinch back the growing tips of seedlings when they reach about 4-6 inches to encourage bushier growth.
- Mulch around the plants to retain soil moisture, since sweet peas enjoy consistent watering, especially in warm weather.
- Fertilize with a high-phosphorus fertilizer to promote blooming, but avoid heavy nitrogen fertilizers, which can lead to excessive foliage at the expense of flowers.
- As flowers fade, deadhead regularly to encourage more blooms throughout the season.
Unlike green pea plants, sweet peas are not edible.
Pests and Problems to Watch For
While generally low-maintenance, sweet pea plants can be affected by a few common pests and issues:
- Aphids: These small pests can be managed by spraying the plant with a strong blast of water or using insecticidal soap.
- Slugs and snails: These can damage young sweet pea plants. Hand-picking or using organic slug deterrents can help protect your plants.
- Powdery mildew: This fungal disease can develop in humid conditions. To prevent it, water the base of the plant and ensure good air circulation by spacing plants adequately.
- Root rot: Make sure your soil is well draining to avoid waterlogged roots, which can lead to rot.
Plant sweet pea seeds in fall or spring. You can improve germination success by soaking the seeds to soften the seed coat. Sweet pea seeds germinate best in soil termperatures between 55° and 65° degrees F.
