Pristine white flowers about three inches across, each petal often marked with a single delicate purple stripe. Rhododendron 'Roblex', sold as Encore Autumn Lily®, grows 4 to 5 feet tall and 3 to 4 feet wide in full sun to part sun, hardy from Zone 6 through Zone 10.
The habit is upright and full with dense branching, and this is one of the most cold-hardy Encores. White reads brightest at dusk and in the shadier corners of a bed.
Encore azaleas can flower up to three times a year. A traditional azalea blooms for a couple of weeks in spring and then stops, while Encores set buds on new growth through the season and bloom again in summer and once more in fall. Spring and fall give the strongest shows, with the summer flush lighter and more scattered. They also take more sun than most azaleas.
Azaleas want acidic soil, roughly pH 4.5 to 6.0, with good drainage and steady moisture. Alkaline ground turns the leaves yellow. Mulch the shallow roots.