Primula vulgaris or common primrose, a species of plants from the Primulaceae family, is found in Europe and parts of Africa and Asia.
This perennial grows around 4–12 inches high and 4 – 9 inches wide. The wrinkled leaves are oval, somewhat serrated and about 9 inches long with a width of 1 – 2 inches and form a basal rosette.
It has a short single stem at the center of the rosette producing bell-shaped fragrant yellow and white flowers about 1 – 2 inches in diameter – sometimes, pink or white flowers are also frequently seen in wild plants. The flowers grow in clusters, normally appearing in spring, and are very dependent on insect pollinators like bees, butterflies, wasps, beetles, flies, and bumblebees for pollination.
The ovary later forms a valved capsule containing tiny black elaiosome seeds that are often distributed by ants; a few birds also like to feed on the seeds and help in distributing them.
This plant is almost evergreen when growing under favorable conditions. In the wild and under suitable growing conditions, this plant can carpet the ground in woods and dappled hedgerows.
It is found growing naturally near streams, bushes, orchards, and open deciduous forests, sometimes also appearing in meadows. In Europe, this plant is found thriving naturally in nutrient-rich, loose, and loamy soils in areas with mild winters.
However, in populated areas, it has been suffering from plant collectors so very few natural displays of these plants growing in abundance can be found now. Nevertheless, it is commonly found growing on verges along motorways and railway embankments wherever human interference is limited.
Several countries have enacted laws making it illegal to pick or remove these plants in the wild to protect the species from too much damage.
Generally, this plant is rather easy to grow in flower beds, rock gardens, borders, under trees, and in open gardens, creating a beautiful sight with their yellow flowers and attractive green foliage.
It also provides a wonderful display when growing along hedgerows, paths, ponds, streams, and marshy areas. This plant can be cultivated in containers of humus-rich soil and kept on porticos under partial shade.
This plant grows well under partial shade and can tolerate full sun in places where summers are not very hot. Sun exposure should be just enough to provide some light but not too strong that it dries up the surface of the soil.
Like most other perennials, this plant has modest watering requirements. Generally, water it once a week – more if necessary, particularly in hot summers. It loves moist soil but won’t tolerate wet or soggy soil, since root rot can easily set in causing wilting and making foliage yellow. If this happens, let the soil dry completely before resuming watering.
This plant prefers moderate levels of humidity.
It is hardy in zones 4 to 8 and prefers temperatures between 35 – 80°F. However, it is important never to expose seedlings to a temperature above 68°F as this might inhibit growth and bud development.
It prefers organic, humus-rich soil but can also tolerate heavy clayey soil. If your soil is poor, occasionally add organic compost to increase nutrients. Mulching might be necessary for climates with hot summers to retain moisture and cool the roots.
This plant can rapidly get root-bound unless it is repotted every year and divided after the flowering season. Use regular potting soil amended with compost in larger containers with many drainage holes.
After easing the plant out of its home, gently shake it to remove the old soil, divide it if necessary, and repot into the new containers. When repotting, always make sure that the crown is slightly raised above the soil. Regular repotting will prevent fertilizer buildup as well – if you do fertilize the plant.
This plant is normally propagated from seed and root division.
Propagation by seed
This should be done when the seeds are ripe. Sow the seeds in a seed tray of potting soil, making sure the temperature is controlled and doesn’t rise over 68°F. After the seeds germinate, wait until they are about 6 or 7 high before transplanting, picking them out carefully from the tray. Transplant them into individual containers, later planting them in the garden or continue growing them as potted plants.
Propagation by division
This is best done after the plant finishes the flowering season or when you are repotting potted plants. First, dig up the plant and study the root clump carefully. Tease out any small plants on the edges with your fingers and keep them aside. Now push a trowel straight into the large clump and separate it into different sections. Replant the divided sections with rich well-draining soil and water the new divisions thoroughly.
This plant generally doesn’t need feeding. Adding fresh compost in spring will be sufficient to supply it with nutrients.
This is a plant that needs very little maintenance or pruning. Generally, all you need to do is deadhead faded flowers (unless you want to harvest seed) and remove old leaves.
This plant is generally free from insect or disease problems. However, keep a careful eye out for aphids, mites, snails, and slugs. The two insect pests can be treated with horticultural insecticides or insecticidal soap. Organic controls like coffee grounds or crushed eggshells can also be used instead of chemical repellents to control slugs or snails.
As for diseases, this plant can be vulnerable to root rot from soggy soil, along with some viruses in poor growing conditions. Fungal attacks from mold, rust, powdery mildew, botrytis, and leaf spots can also wreak havoc. All these can be prevented by providing this low-maintenance plant with proper watering and suitable growing conditions.
As mentioned above, flower production can be affected by inappropriate temperatures above 68°F as seedlings. Hot temperatures might also cause heat delay, turning this perennial into an annual plant that will die from the heat.