Primula is a genus of flowering herbaceous perennials consisting of over 400 different species including primrose, cowslip, oxlip and auricula. Primulas are native to temperate regions in both the Northern and Southern hemispheres, and bloom during the late spring. The flowers can be any color except for green, and many species and cultivars have blossoms featuring two colors. Primulas can grow up to 1 foot in height and require only routine maintenance to thrive in most regions.
Plant primulas during early spring in a location that receives direct morning sun and partial afternoon shade. Spread 2 inches of organic compost over the site prior to planting and use a garden tiller to incorporate it into the soil.
Dig a small hole in the soil just large enough to hold the primula seed. Cover with a thin layer of soil and water thoroughly. Space other primulas at least 8 inches away to allow plenty of room for growth.
Water primulas twice per week during the first year of growth, ensuring the roots are never allowed to dry out completely. Reduce the frequency of watering to once per week after the first year when the root system is established.
Feed primulas once every two months using a balanced 10-10-10 NPK fertilizer. Water thoroughly both before and after applying to prevent root burn from the sudden influx of nitrogen. Follow the instructions provided by the manufacturer for proper dosage. Do not fertilize between November and February.
Cut primulas back to half their height just before the onset of winter and spread a 2-inch layer of mulch over the soil surrounding the plants. This will help insulate the soil and protect the roots during cold weather. Remove the mulch as soon as the risk of frost has passed.