Garden Scheme
Plant library · Annual Flowers
Lathyrus odoratus
Sweet pea is a fragrant annual vine that brings a tall but narrow vertical layer to the garden. Growing to about 6 feet tall and roughly 1 foot wide, it earns its space on a trellis rather than across the bed. Its late-spring to early-summer flowers make it especially useful where a border, fence line, or cutting area needs an early-season lift.
Space Sweet Pea 6 inches apart, measured center to center (15 cm).
The mature spread is about 12 inches (30 cm), so plants set at that distance grow together into continuous cover.
Treat 6 inches as a planning baseline — cultivar and local growing conditions shift the final footprint.
Place sweet pea at the back of a border or along a fence, wall, or dedicated trellis where its stems can climb without leaning into lower plants. Install the support before planting, and keep the planting strip close enough to a path for frequent flower cutting and removal of spent blooms. It also suits a cutting garden, where its seasonal display can be managed separately from permanent bed structure.[1][2][3]
Set plants 6 inches apart, center to center, to form a closely planted climbing row. Although each plant has a mature width of about 1 foot, the stems can be trained upward and gathered onto a narrow support, keeping the bed edge more open than the eventual foliage spread suggests. Allow clear access on at least one side of the row for tying in stems and cutting flowers.
Use a full-sun position with fertile, well-drained soil that does not dry out quickly. Regular moisture is most practical in a bed within easy hose reach or on drip irrigation, particularly when plants are climbing densely on a support. Avoid sites that remain soggy after rain or are shaded for much of the day, since flowering is reduced in shade.[1][2][4]
Treat sweet pea as a cool-weather annual and reserve its support for a seasonal display rather than a permanent screen. Blooms arrive from late spring into early summer, then heat can shorten the display. Pick flowers regularly and remove spent blooms to keep the vine producing; plan a later-season replacement for the same trellis if the structure must carry visual weight through summer.[1][3][4]