The plants in the Primula family are commonly called primrose. The tiny herbaceous perennials are ideal in containers, rock gardens or along borders. Hundreds of varieties exist that sport a wide range of colors. Spring blossoms appear in brilliant shades of purple, pink, white, red, orange, yellow and blue. The foliage of the plant is a subtle green that appears fuzzy and forms ground-hugging rosettes.
Plant primroses (primula) in the early spring. They flourish in semi-shade. The plants also do well in full sun unless the summertime temperatures soar to above 80 degrees Fahrenheit, which can kill the primrose. Choose a spot in the garden where larger plants will not overshadow the small primrose, which usually only grows between 6 to 12 inches in height.
Primroses can also be easily transplanted in the springtime without fear of bloom loss. Primroses can be successfully grown indoors if cool nighttime temperatures can be maintained. The primrose prefers nights to be around 50 to 60 degrees Fahrenheit.
Plant primroses in soil that is rich in humus. They prefer slightly acidic soil with a pH of 6.5. The location should be well draining. Primroses prefer moist soil because they do not withstand wet feet well. When planting mix organic matter into the soil at a ratio of 50 percent garden soil with 50 percent cow manure, peat moss, sawdust or other organic material. Plant 6 to 12 inches apart.
Planting & Watering
Plant the primrose so that the crown of the plant is level with the soil. If the plant is placed too deeply it could easily suffer from rot and a fungal infection. Plant four to six inches deep. Water the primrose so the soil stays moist but it's not overly saturated. Primroses adore moist soil but they do not do well if the soil is soggy.
Many primroses will bloom into summer if regular watering is maintained. All varieties of the Primula plants do not like temperatures to exceed 80 degrees Fahrenheit. The plants will cease to bloom and often show wilt during the hot summer months.
Remove all dead flower heads and dead leaves as they appear to maintain the primrose's health. Fertilize all varieties of primula in the spring using a 10-10-10 or a 5-10-5 fertilizer. Follow the directions on the label for application. If the primula is a double-flowering primrose then use only the 10-10-10 fertilizing mixture because they are a heavier feeders then the single-flowering primrose. Fertilize again after flowering has ended.
Watch for spider mite infestation in the height of summer. If the leaves on the primrose turn brown and curl, it might suffer from spider mites. Look closely for tiny webs and inspect under the leaves for red, brown or black spots.
Wash the primrose thoroughly using a hose and water to remove spider mites. Repeat the washing every other day until spider mites are eradicated. Ladybugs can also be purchased at most garden supply stores. Ladybugs enjoy dining on spider mites and many other garden pests.