Prized for their pretty, intensely fragrant flowers, most sweet peas are grown as cool-season annual vines, reaching 4 to 6 feet tall, but some are bushy 1- to 3-foott-tall dwarfs.
All produce lovely clusters of 1-inch long, pea-type flowers in white, light orange, yellow, lavender, blue, red, purple; some produce bi-color flowers. Longer-stemmed types are classic cut flowers. Attractive gray-green leaves nicely complement these blossoms. Bloom time depends on the variety with many blooming in early winter in mild climates and early spring to midsummer elsewhere. Notable Varieties 'Royal Family' is especially heat-tolerant and fragrantMost older varieties, such as 'Antique Fantasy' and 'Painted Lady' are fragrant while newer cultivars may not beCare: Sweet pea prefers fertile, well-drained soil, enriched with lime when possible. Sweet peas should be fertilized heavily, and watered well. They grow best in areas with long, cool growing seasons. A support structure, such as a trellis, often necessary for any sweet pea growing more than a foot or so high. PlantingPlant directly in the soil when the weather is cool and a light frost (or close to it) is still possible, perhaps 2 to 3 weeks before the last frost in late winter or early spring.In cooler regions, can start indoors 4 to 6 weeks prior to last frost. Plant outdoors when seedlings are 1 inch tall.In Zones 8 to 11, plant seed directly outdoors in late autumn or early winter. Soak seeds in water 24 hours before planting, then plant 1/4-inch deep and 6 to 12 inches apart. Pests and Diseases Powdery mildew can occur in warm weather. Anthracnose, block root rot, aphid, and two-spotted spider mite are also possible problems.