Primula 'Penumbra'
SILVER-LACED PRIMROSE, SILVER LACE POLYANTHUS
Family: Primulaceae
Pronounced: PRIM-yew-la

Quick Jumps
Growing Guide
Rainy Side Notes
GROWING GUIDE

Origin:
Garden
Plant Group:
Perennial.
Hardiness:
Sunset zones: 1-24.
USDA zones: 5-7.
Heat zones: 7-5.
Mature size:
Height: 4 inches (10 cm) with flowers 10 inches (25 cm).
Width: 9 inches (23 cm).
Flowering period:
February to June.
Flowering attributes:
Clusters of fragrant flowers top stems, above the rosette of leaves. The petals are deep mahogany red to almost black, edged in white, with yellow centers.
Leaf attributes:
Evergreen, heavily veined, 7-inch long, dark green leaves.
Growth habit:
Rosette forming.
Light:
Partial, dappled shade and full sun (full sun in cool summer climates only).
Soil:
Moist, humus rich, well-drained, neutral to slightly acidic soil.
Feeding:
In spring, side dress with compost or top dress with leaf mold and a complete organic fertilizer.
Propagation methods:
Divide after flowering.
Divide in autumn in mild winter areas.
Pests and Diseases:
Slugs and snails may be a problem.
Rainy Side Notes

Mary A. Robinson notes in her book "Primulas the Complete Guide" that florists deem the silver lace polyanthus group “fit only for the rubbish heap.” However, like Robinson, I wouldn’t listen to the naysayers when it comes to this primrose in our gardens. It may be harder to find than the gold lace group; however, it’s a wonderful addition to the shade garden and the first of the silver lace group to become available in the nursery trade.
I love that the cultivar name Penumbra is, according to Merriam Webster’s Dictionary, “the shadow cast by the earth or moon over an area experiencing a partial eclipse.” It also means “the partially shaded outer region of the shadow cast by an opaque object,” both of which describe the flowers perfectly. It originally comes from the Latin paene (almost) and umbra (shadow).
Although this plant comes with cautions about slug and snail problems, my primroses receive little damage. My slug herd never developed a voracious appetite for them.
These long-lived primroses have exceptionally lengthy bloom times. Some years they may flower deep into summer in our cool maritime climate. For best results, give them supplemental watering during our typical dry season.

Photographed in author's garden.

Gardening for the Homebrewer: Grow and Process Plants for Making Beer, Wine, Gruit, Cider, Perry, and More
By co-authors Debbie Teashon (Rainy Side Gardeners) and Wendy Tweton
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