|Boursault is a sturdy, hardy shrub, to -25 degrees Fahrenheit, bearing sizable lavender flowers held in round trusses. Shrubby, evergreen "ironclad" rhododendron with medium leaves. Grows to 5 feet tall.
There are between 500 and 900 species of evergreen and deciduous plants in the Rhododendron genus. Azaleas fall into this category. The evergreen rhododendron is characterized by medium to long, elliptical leaves and large, clustered, trusses of, late, showy, spring to early summer flowers, ranging in colors from red, pink, white, lavenders, purples and even yellow and orange. Form maybe low and mounding to gangly and almost tree-like with age.
All rhododendrons love well-drained, acid soil and should be planted high, preferably on raised beds. Partial shade is preferable too, though many plants grow quite well in full sun in cooler, more forgiving climates. In general, the evergreen rhododendron tends to do better in cooler areas of zone 7 and lower, thriving in the Appalachian Mountains and the Pacific Northwest.