GARDENING : Happily Led Down the Primrose Path

Primulas, better known as primroses, add vivid colors to what can be a drab winter garden. Although they’re often planted in November, primroses can be planted now to yield months of vibrant color, especially along the coast where they’ll bloom into the summer months.

“Primroses command attention in any garden setting because of the clarity of their colors,” said Mary Lou Heard of Heard’s Country Gardens in Westminster, which specializes in perennial plants. “They perform well in shade, but also thrive in full sun during the winter when the bright light coaxes more blooms from them.”

Heard recommends planting primroses under deciduous trees or between perennial plants that are dormant during the winter. She also uses them as border plants, marking pathways or in containers.

“Because I’m originally from the East, to me primroses are heralds of Easter, since any sign of life in winter is a promise of the approaching spring,” Heard said.

There are more than 600 species of primroses, but only a limited variety are suitable for the relatively low humidity and warmer temperatures of Southern California. They’re technically perennial plants, but perform as annuals in this benign climate.

The most popular in this region are P. polyantha , also called English primroses; P. obconica ; P. juliae hybrids, Julian primroses; and P. malacoides , fairy primroses. English primroses are a group of hybrids which produce up to two-inch flowers on thick stems that can reach 12 inches high. Their range of brilliant colors includes solid colors of red, pink, blue, white, yellow and orange, and the newer picotee and bi-colors.

Obconica primroses are similar in appearance to English primroses, but have round, soft-hairy leaves and a longer bloom time. Julian primroses are small, dwarf primroses that are also popular because of their vibrant colorations. Fairy primroses produce lacy whorls of flowers on upright stems.

Primroses originated in moist meadows and woodlands, in climates that are cool and humid. Cowslips, often mentioned in English literature, are a variety ( P. veris ) which Southern Californians must enjoy in other climates since they won’t grow here. But primrose enthusiasts can choose from a selection of varieties and a number of different colors.

“We grow 21 different colors of a variety of English primrose called the Santa Barbara strain, originally known as Pacific giant hybrids,” said Mark Bartholomew of Hi-Mark Nursery in Carpinteria. The commercial wholesale nursery grows more than 200,000 primroses and supplies Amling’s Nursery in Newport Beach, Heard’s Country Gardens and Roger’s Gardens in Corona del Mar.

“They’re relatively trouble-free in the home garden,” Bartholomew added. “They thrive in rich soil, appreciate ample water, and need fertilizing only when they’re flowering.”

Bartholomew recommends using any high-bloom type of fertilizer that is water soluble. Excessive nitrogen can produce excessive leaf growth. Gardeners can fertilize once a month or every two weeks if using half the recommended dose.

Phil Miller of Roger’s Gardens notes that primroses are a valuable garden addition now.

“We sell approximately 100 flats of primroses each week,” he said. “They’re excellent plants for both containers and in the ground.”

In addition to the Santa Barbara strain (termed Super Giant here), Roger’s Gardens offers a number of other varieties: P. obconica ; fairy; pageant; two dwarf varieties, Julian and Romeo; picotee and Chinese primrose.

“The Super Giant has a lot of punch in a garden because of its large flower size,” said Miller. “The new picotee, a type of English primrose, is also attractive with the different colors around the flower edge.”

Miller recommends massing primroses in the ground for a dramatic statement. He suggests planting white cyclamen along the border and massing mixed colors of primroses behind them. He and Heard also like to use baby tears to soften brick or concrete border edges.

For containers, Mille recommends as companion plants to the primroses campanula, mother fern, cyclamen, variegated ivy or liriope, a grass-like perennial.

Wherever and however they’re planted, gardeners will have to be watchful that snails don’t destroy their handiwork. Primroses are a favorite food for snails who feed on their foliage. To control the problem, snail bait can be scattered at the base of each plant. Nontoxic snail baits can be used where pets or small children may have access to the bait.

Some gardeners also like to use diatomaceous earth, a nontoxic abrasive and desiccating powder composed of minute, sharp-shelled sea creatures (diatoms).