Sweet peas are old-fashioned favorites that have been cultivated for centuries! Hardy annuals, these graceful vines thrive in many garden conditions and offer a constant supply of gorgeous fragrant blossoms all summer long. Soak the seed overnight before sowing directly in the garden as soon as the ground can be worked in early spring. As sweet peas are heavy feeders, work generous amounts of organic matter into the soil prior to planting. Mulch may be applied to the soil to reduce temperature and moisture loss.