Cool weather annual that is best grown in rich, humusy, medium moisture, well-drained soil in full sun. Tolerates some light shade. Compost may be incorporated into the growing area prior to planting. Best performance occurs in cool soils (soil mulch helps) in cool summer climates with good air circulation. Sweet pea can be a challenge to grow well in hot and humid summers where, as temperatures rise, plants will decline rapidly to the point where removal from the garden becomes necessary. Provide even moisture and regular fertilizer throughout the growing season. Avoid overhead watering to the extent possible. In St. Louis, start seed indoors about 6-8 weeks prior to last spring frost date to maximize bloom time. In warm winter areas, seed may be sown in fall or late fall for winter and spring bloom. Avoid planting sweet peas in the same location in consecutive years. Plants may be grown in bushy mounds or as climbers. Climbers need a support structure on which to grow (e.g., trellis net, fence, strings, stakes or bamboo pyramid). Deadhead spent flowers to prolong bloom. Propagate by seed.