The genus Primula offers the shade gardener plants with an assortment of colors including white, magenta, pink, yellow, and orange. Some flowers are bicolored and others are fragrant. There are several hundred species, varying in height from a few inches to 3 feet tall. Flowers appear in February in mild winter areas and in April and May in northern climates. These perennials are hardy to Zone 5. The crinkly, tongue-shaped leaves form basal rosettes and are evergreen when temperatures do not drop below 15°F. For an array of spring color, plant primulas with bulbs.
New plantings can be established from nursery bedding plants, divisions, or from seeds started indoors in late winter or early spring. Primulas grow best in medium to light shade with rich, well-drained soil. Keep the soil evenly moist, and fertilize occasionally with a complete fertilizer. Divide crowded plantings every two to three years after flowering. New plants appear in the garden from self-sown seed and from surface roots, but primulas cannot be considered invasive.
The easiest-to-grow primulas are Primula vulgaris, English Primrose; P. x polyanthus, Polyanthus Primula; P. japonica, Japanese Primula; and P. sieboldii