The Drumstick Primrose

By Pam Eveleigh

If you’ve never seen Primula denticulata, the “drumstick primrose”, then you might just wonder what kind of plant could deserve such a name. But that name aptly describes the look of this beautiful primrose. It forms its flower buds in the late fall, holding them until early spring in the center of a large resting bud. The flowers start opening before or just as the leaves start to grow and at that time the whole inflorescence is tucked down in the center of the plant. As it continues to grow the flower stalk elongates and more flowers open, until the plant consists of a ball of flowers perched on top of a stout stalk. It then looks like a drummer’s stick.

Primula denticulata is found in a large area of the Sinohimalaya and is variable throughout its range. It grows in wet, open meadows. Plants in the wild are usually a soft purple with a yellow eye, but flower color in cultivation ranges through stunning shades of red, blue, dark purple, pink and white. Many of these selections have been named and offered in the nursery trade. The size of flowering plants also varies from a few inches to a normal 13 inches tall (18 inches in fruit). Though the leaves are small and just starting to grow when the plant is flowering, they eventually expand to 12 inches or more. Give individual plants lots of room! Fortunately the leaves are deciduous and disappear in readiness for next spring’s flowering display. Some gardeners have been known to move their plants to a holding bed after flowering so they don’t take up so much room. The plants are moved back once they have formed resting buds.

There is only one subspecies of Primula denticulata: ssp. sinodenticulata, which is found in Burma and China. It is distinguished by its extremely long flower stem that can be up to 6 times the size of the leaves! Related primulas include P. cachemiriana and P. glomerata. Both are readily found in cultivation and exhibit a drumstick appearance.

Primula denticulata has been in cultivation since the early 1800s. It is easily grown in fertile, moist soil in part shade. It grows equally well in acidic soils or limey soils. Like any primula, it prefers not to dry out, but I have found the large leaves act as an indicator that my flower beds need water. Once the leaves start to droop then water the plants immediately. If they are dry for too long, then watering may cause rot rather than recovery! Primulas are heavy feeders and Primula denticulata will benefit from a rich soil, a yearly top dressing of compost and regular fertilizing.

Plants can last for many years. They can be moved but the thongs, or thick anchor roots break easily. Try moving the plant with the soil intact around the roots to maintain their spread. If the plant is already bareroot, then gently fan the roots out and cover them with soil. It is less difficult to plant out young plants and they grow vigorously. If you do move your plants and the roots break, don’t despair. Root cuttings are a recognised method of propagating Primula denticulata so the remaining roots may form into new plants. Primula denticulata can also be propagated by division after flowering. The individual crowns are teased apart and replanted.

Primula denticulata produces a head of many small capsules containing fine seed. Examine the capsules closely to see when they change color from green to brown and when the end of some capsules open into a star-shape. The seed is then ready to be collected by either shaking the head over a bowl or bag, or by gently crushing the capsules and sifting the results through a fine sieve to remove the chaff. Prolonged exposure to wet when the seeds are maturing may produce a poor yield and mouldy seed. The seed exchanges usually offer garden collected seed and wild seed is introduced regularly. Seed germinates quickly when sown immediately and can be sown directly into the garden. You will likely find that your plants will start self sowing anyway. Seed may be stored in the refrigerator for later years though viability is reduced over time. Plants generally bloom in their second year from sowing. If muddy colored plants appear, then pull them out and keep the better color forms.

Primula denticulata is a hardy plant. It can easily survive long cold winters such as those in Scandinavia and Canada. The resting buds resent winter exposure which can be avoided by protecting the buds with dry leaves, frost cloths or evergreen branches where snow cover is unreliable. They also resent freezing when wet which can be solved by using covers that allow for air circulation in milder wet climates. I have noticed that young plants many heave partway out of the ground during winter, but the thick anchor roots prevent total exposure. These plants can be pushed gently back into the ground in the spring.

Primula denticulata is one of the most popular primulas to grow. A search on the World Wide Web will produce a wealth of nursery catalogue entries and articles. Pictures showing the variety of color forms are listed, including pictures on the American Primrose Society Website found at www.americanprimrosesoc.org and on Primula World found at www.primulaworld.com. Information on Primula denticulata can be found in any book dedicated to the genus Primula such as Primula by John Richards, The Genus Primula In Cultivation and The Wild by Josef Halda and Primulas The Complete Guide by Mary Robinson. This species is usually mentioned in general gardening books under the primrose section.

If you are an experienced primrose grower or just starting out, Primula denticulata is for you. It is easy to grow, boasts a wide range of colors, has a long flowering period and even makes a great cut flower! So that is the Drumstick Primrose. Not a very elegant name perhaps but a plant everyone should be enjoying.

Photo Credit: Debbie Hinchey