Crocus

Fundamental Facts

HARDINESS: Zones 3 to 7
PREFERRED SOIL pH: Adaptable
PREFERRED SOIL TYPE: Average
PREFERRED LIGHT: Sun to partial shade
ATTRIBUTES: Small, cup-shaped while, yellow, or lilac flowers; tor beds, naturalizing
SEASON OF INTEREST: Spring or fall
FAVORITES: 'Blue Pearl', 'Goldilocks'; 'Remembrance', 'Pickwick', C. speciosus
QUIRKS: Needs winter chilling to initiate flowering
GOOD NEIGHBORS: Lawn grass, peonies, lilies, spring-flowering shrubs, balloon flower
WHERE IT GROWS BEST: In full sun and well-drained soil
POTENTIAL PROBLEMS: After several years, overcrowding reduces flowers
RENEWING PLANTS: Lives years; divide big clumps and replant corms every 5 years
CRITTER RESISTANCE: Poor; corms are vulnerable to rodents, rabbits, and deer
PLANTING DEPTH: 3 in (7.6 cm)
SOURCE:Corms
DIMENSIONS: C. chrysanthus 2-4 in (5.1-10.2 cm) tall, 2 in (5.1 cm) wide; Dutch crocus 5 in (15.2 cm) tall, 4 in (10.2 cm) wide

Crocus in the Landscape

Few sights are as welcome as the first crocus of the season poking their heads through patches of melting snow. The small, ground-hugging, cup-shaped flowers open during the first sunny days of spring, and are clad in gay hues of purple, yellow, and white. Some have petals veined in contrasting shades, some are subtle pastels, and others are bright hues, but all enliven the landscape when few other plants are in bloom. These diminutive heralds of spring can grow almost anywhere, but because they stand just a few inches above the soil, it's important to place them where you won't miss them. Group them in a bed, sprinkle them throughout the lawn, or use them to line a walkway or accent a rock garden.

Crocuses do most of their growing while hardy perennials remain dormant, so they make excellent companions for peonies, lilies, and plants that wait until summer to gain size, such as balloon flowers. Crocuses also paint a delightful picture when informally grouped at the bases of deciduous shrubs and trees.

All in the Family

Often called the snow crocus because it blooms so early. Crocus chrysanthus is available in several cultivars whose names reveal their colors, the best being 'Blue Pearl', 'Cream Beauty', and 'Goldilocks'. If you'd like larger flowers, try Dutch crocuses, such-as-purple 'Remembrance', lilac-striped white 'Pickwick', golden 'Mammoth Yellow', and white 'Jeanne d'Arc'.

Not all crocus bloom in spring. C. speciosus opens its lavender blossoms in fall, as does a similar-looking plant, Colchicum speciosum, often called autumn crocus. The large violet flowers of autumn crocus make fall feel like a second spring, and the blooms are followed by grassy green foliage that persists through winter in many areas.

Growing Crocus

Crocuses grow from small, bulblike corms sold in autumn. Plant the corms after the soil cools in the fall, in a sunny, protected spot. Set crocus corms 3 in (7.6 cm) deep, pointed end up, and 2 in (5.1 cm) apart.The most impressive display comes when crocus are planted in groups of 10 or more, so that they look as if they were planted by Mother Nature herself.

After the blossoms fade, it's important to allow crocus to keep their leaves until they naturally fade away, because they will continue to photo-synthesize and nourish the old corms as well as the new ones that are constantly developing underground. The foliage is easily camouflaged by planting crocus among leafy perennials. In the lawn, crocus leaves blend into green grass. Should crocus become so crowded that they stop blooming, dig and separate the corms as the leaves begin to yellow in late spring. Lift and separate the corms and replant them without delay. Spring-blooming crocus need to be divided every 5 years or so, but autumn crocus can be left untouched for many years.

Crocus emerges so early that it is virtually trouble-free. It blossoms and goes dormant before most pests and diseases pose a threat. Rodents, however, relish the corms. To protect corms, encase them in a cage of wire screening or in commercial wire bulb baskets at planting time. You can also cover corms with coarse, gravel before filling the planting holes with soil to discourage digging rodents.