When Does the Annual Sweet Pea Bloom?

The sweet pea (Lathyrus odoratus) fills the garden with fragrance and delicate blossoms. This annual climbing vine is a highly scented ornamental closely associated with the common garden pea. Though the flowers are sweet smelling, sweet peas aren’t an edible crop. Sweet peas flower in the summer in cool climates and at the spring and fall in light Mediterranean climates.

Gentle Climate Planting

Sweet peas like to bloom if the weather is cool. In a Mediterranean climate with light — frequently frost-free — winters and warm summers, the best time to plant is in late summer and early autumn. A late season planting contributes to flowers in winter and early spring. For holiday flowers, get your seeds in the ground by Labor Day. You can also plant quite early in the spring to get an early summer bloom time.

Cold Climate Planting

In regions with cold winters where temperatures often fall below freezing, sweet peas are planted in the spring after the last frost date. By early to mid summer, the fragrant flowers are in full bloom in the garden. Sweet peas are best planted right into the garden bed, however, in regions with a long, cold spring, it is possible to start seeds indoors four to six weeks before the last frost date in your area. By the time that the ground thaws, you will have plants already growing to really go in the ground.

Planting Seeds

The seeds should be planted 1 inch deep in moist soil and spaced 2 to 3 inches apart. Sweet peas germinate best in a ground temperature between 55 and 68 degrees Fahrenheit. You can accelerate germination by soaking the seeds in warm water for 24 hours before planting or by gently nicking the seed coat with a pin or knife. Germination commonly takes 10 to 14 days but can be as fast as two to three days once the seeds have been jammed or nicked prior to planting.

Growing Sweet Peas

When planting sweet peas, a spot in the sun where the soil is shaded by other low-growing plants is ideal. It is one reason sweet peas are so happy in the vegetable garden; they can develop with their roots shaded from the other plants and many vegetable gardens are at a spot that gets lots of sunlight. This climbing annual vine will climb a trellis or climb up corn stalks and end around sunflowers.

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