Primroses are small colourful flowers that work well to brighten gardens or front yards. Mature primroses can bloom for several months in the spring and early summer. Primroses require shade, so prepare to plant them on the north side of your house or under shade trees. The most common Primrose variety available in stores is the Polyanthus Primrose. You can plant primrose seeds outdoors, or plant them in a greenhouse and transplant them to your garden after germination.
Planting Primrose Seeds Outdoors
Plant primrose seeds outdoors only when temperatures are below 26.7 degrees Celsius. Primroses do better in cool weather. Plant seeds in early August for autumn germination, or in November for germination in the spring. Make sure the seeds are out of direct sunlight. Cover the seeds with about 1/16 or 1/18 of an inch of sand and peat moss soil. This thin layer will allow minimal necessary light to reach the seeds. Cover the seeds with thin cheesecloth to block direct sunlight if necessary. Check on the seeds daily.
Planting Primrose Seeds Indoors
You can sow primrose seeds in a greenhouse or a cool indoor location at any time of year. Prepare each cell in a planting tray with seed starting soil mix, and moisten the soil. Place one or two seeds in each cell, and cover the seeds with a light dusting of peat moss and sand, about 1/18 of an inch deep. Transport germinated seeds to a garden bed in August if temperatures are below 26.7 degrees Celsius. Cover the young primrose plants with a cheesecloth if necessary to protect them from direct sunlight, and cover them for protection in freezing temperatures.
When to Fertilize
Fertilise young primrose plants in the early fall to promote growth before temperatures drop below freezing. Then fertilise the plants again in early spring before they begin to grow or bloom. Sprinkle commercial fertiliser mix over the entire primrose bed.