Buttermint Rhododendron Buttermint Rhododendron has large yellow flowers stand out above thick leathery leaves. Compact growth habit shrub. Primary Color: Yellow Bloom Time: Midseason Height in 10 Years: 3' Hardiness (Temperature): -5 Sun / Shade: Morning Sun, Afternoon Shade Landscape Category: Shrub Genus: Rhododendron More plants in: Coming Soon Find out if this plant is available: Rhododendron and Azalea Availability List