Plant library · Ornamental & Flowering Trees
Vitex agnus-castus
Chaste Tree is a multi-stemmed shrub that can also read as a small tree in the landscape, building a broad 15-foot presence at maturity. Lavender-blue flower spikes bring vertical summer-to-early-fall interest, while its open-scale form suits a sunny bed where it can stand above lower planting. Use it as a single focal plant rather than trying to fit it into a narrow foundation strip or crowded mixed border.
Give this shrub a position at the back or outer edge of a large bed, where its height will not block shorter plantings or pinch a route beside the house. Leave a clear approach from a path, lawn edge, or service area so the branching structure can be pruned without stepping through neighboring plants. Its summer flowers attract bees and butterflies, so place it where that activity is welcome rather than directly beside a frequently used doorway or tight seating area.
Space Chaste Trees 15 feet apart, center to center, for a planting that can reach its natural mature width without interlocking too soon. Reserve roughly a 15-foot-wide circle for each plant and keep that footprint clear of walls, fences, overhead eaves, and permanent garden furniture. In a border, allow extra room along the front edge for access; low, drooping branches can otherwise occupy the same circulation space as a path.[1][2]
Set Chaste Tree in full sun and use it in a lower-water part of the plan once established. A well-drained site is important, making it better suited to raised, sloping, or freely draining beds than to places that stay wet after rain. Keep it out of irrigation-heavy planting zones, where its watering needs would conflict with moisture-loving neighbors.[1][2]
The flower display runs from summer into early fall, so let the plant hold a visible position during the warm-season garden rather than hiding it behind later-growing shrubs. It flowers on new wood, allowing early-spring pruning to shape the footprint before seasonal growth begins. Plan for a deciduous winter outline and avoid relying on it for year-round screening.[1][2]
In colder parts of its range, winter dieback can change the plant’s height and structure from year to year, even when the roots survive and regrow. Avoid using it as the only plant assigned to a fixed privacy or shade role. Seedlings may also appear in nearby beds, so leave room to inspect the ground around the plant and remove unwanted young plants before they settle into the design.[1][2]
Editorial content updated 2026-07-20.