Rhododendron 'Praecox' is a beautiful early-flowering shrub bearing rosy lilac flowers in profusion in late winter to early spring. It is underplanted with the reddish-purple blooms of Crocus tommasinianus 'Whitewell Purple'. Among the earliest to flower, this crocus withstands wind, rain and is a great choice for naturalizing.
Other pairing options for your early flowering Rhododendrons are possible. Among the beautiful bulbs in their prime in late winter to early spring are Chionodoxa, Crocus chrysanthus, Narcissus bulbocodium, Narcissus cyclaminus, Scilla mischtschenkoana.