, Muskogee, OK

December 26, 2012

Hybrids spur primrose comeback

By Molly Day
All the Dirt on Gardening

— The English primroses made famous by Shakespeare grew wild in shady meadows. Primroses have since faded from cottage gardens, but new hybrids are helping them make a comeback.

There are more than 400 primula species that bloom in early spring on stalks above rosettes of crinkly leaves. The common primrose, Primula vulgaris, has single flowers on 6-inch stems. It is related to cowslips (Primula veris) and oxlips (Primula elatior).

Primula sieboldii goes dormant in the summer, although if they are mulched and watered the rhizomes will spread to send up even more the following spring. The flowers are pink, white, purple or mauve on 12-inch stems.

Polyanthus primroses are easy-to-grow hybrids. They need to be divided every few years as they spread. They have large clusters of red, purple, yellow, white, pink or blue flowers on stems that can grow to a foot tall. Plant them with spring flowering bulbs and cut them back by half after they finish blooming.

Drumstick primrose (Primula denticulata) will self-sow and spread in the right conditions. It blooms early with lavender and purple flowers on 2-inch stems.

Primroses are cold hardy in USDA zones 4 to 9 but cannot thrive in warmer zones. In half-shade locations where they are watered, primroses will become perennials. They can also be used as houseplants and as annuals in containers outdoors. They like soil amended with composted leaves, manure and other composts.

All primroses are resistant to insects, disease, rabbits and deer – but not deer-proof. Heat stress can bring spider mites. If they are planted too close together, they can get leaf spot. In the summer, mulch them with chopped leaves or other organic material to protect them from the heat.

Plants will be available in garden centers in early spring; the seeds are started in January. German Primrose, Primula obcondia, seeds produce plants with large, fragrant, single flowers on 10-inch stems. Flower colors include lavender, red, pink and white.

Plant seeds in potting soil and barely cover them with vermiculite. Put the pots outdoors on the north side of a building where they will be exposed to weather, but protect them from direct sun, wind and strong rainfall. During droughts, water them from the bottom and let them drain.

When the seedlings have two sets of leaves, move them to flats with their seed starting soil. You can keep them in pots over the spring and summer and transplant them into a permanent garden spot in the fall.

For spring plants, start the seeds in January but keep them inside a greenhouse or under lights when they emerge.

When planting in the spring or re-planting divisions in the fall, keep the crown above the soil level and do not press them into the ground.

The Double Primula vulgaris Bellarina series is a collection of new hybrids grown from cuttings. The flowers look like roses and come in several colors, including pink ice, nectarine, cream, yellow and cobalt blue. They are hardy in USDA zones 5 to 11 and bloom a long time because they do not produce seed.

Companion plants include other part-shade-loving plants such as Hostas, Virginia bluebells (Mertensia virginica), woodland phlox (Phlox divaricata) and ferns.

To grow primroses as houseplants, keep them on a bright windowsill but out of direct sunlight. Water them regularly and let them drain after watering. Keep them away from heat sources such as furnace vents. Fertilize with liquid fertilizer mixed at half strength when flowering.

Photos of primroses are at The American Primrose Society’s website  (www.americanprimrosesociety.

org) and at

Primrose plants are available from Bluestone Perennials (, and seeds are available from and Primula obconica libra blue seeds are available from