Light: Full to part sun. The warmer the climate, the more shade it requires.
Soil: Moist yet well-drained acidic soils are imperative for success with rhododendrons. A 2-3″/5-7cm layer of shredded bark mulch or pine straw is imperative to keep the shallow roots cool and moist, especially during summer and winter.
Water: Average water needs. Avoid drought stress in all seasons
Fertilizing: One application of a granular fertilizer formulated for trees and shrubs is sufficient. If your plant is yellowing or otherwise looking sickly, this more likely indicates an issue in the soil pH. While applying fertilizer and/or iron will remedy the issue, the fix is only temporary and you should instead devote your efforts to changing the soil pH for a more sustainable, long-term solution.
Pruning: Branches may be removed selectively to create the shape and look you want, but avoid any habitual pruning or cutting back of rhododendrons.