Crocus are annual plants with long life span. They grow from seed pods and they produce flowers only once every two years. These flowers have been used in folk medicine for centuries. They are known to improve digestion, strengthen immunity, relieve pain and other health problems. Crocus seeds are not poisonous but their leaves contain toxic alkaloids which may cause skin irritation if ingested or inhaled.
Crocuses are native to Europe and Asia Minor (Turkey). They were introduced into North America in the 1600’s. Today there are several species of crocuses growing throughout the United States. The most common species is the white crocus, Crocus sativus. White crocus grows along roadsides and road margins where it forms dense stands of small, round greenish-white flowers that appear in late summer or early fall.
The flowers are followed by tiny white berries which ripen in July and August.
White crocus is considered one of the best winter blooming plants because its flowers last until spring. Other types include the red crocus, Crocus rubra; the yellow crocus, Crocus alba; and the purple crocus, Crocus sativa.
The white crocus is a favorite with gardeners because it increases rapidly by self-sowing and blooms in early fall, long before other garden plants come into bloom. It is ideal for naturalizing in lawns and can be used in rock gardens.
The red crocus has smaller flowers than the white crocus and grows about a foot tall. It requires the same culture as white crocus but does not spread as rapidly.
The yellow crocus may be the most popular of all the fall-blooming plants because of its brilliant golden-yellow flowers that cover the earth in autumn. This crocus requires the same culture and conditions as the white crocus.
The purple crocus is a biennial growing about a foot high. It forms a low-growing clump and has narrow, grass-like foliage. The flowers are wine-red with a deep purple tinge on the outside. The leaves turn yellow in the fall. It grows best in dry, lean soil and it does not spread rapidly like other crocuses.
All varieties are easily increased by division of the corms (roots) in early spring before leaves appear. The foliage should be cut back to within an inch of the ground since it is unattractive. Each division should be set out about two feet apart in loose soil.
One of the most popular ways of increasing all crocuses is by the use of corms. These are small, brown, nut-like roots that form under the ground several years before the plant flowers. Each corm sends up a stalk and dies after flowering. If corms are collected as soon as the flowers have died and are carefully dried off they can be stored until needed.
In the fall, select a dry, well-aerated spot in which to store the corms. They can be laid on newspapers or pieces of wood with a one to two inch space between them. Keep them dry and cool (a refrigerator is ideal). Plant in the spring as you would seed from the garden.
Sources & references used in this article:
State of Art of Saffron (Crocus sativus L.) Agronomy: A Comprehensive Review by J Ruksans – 2011 – Timber Press
Crocus biflorus (Liliiflorae, Iridaceae) in Anatolia (part three) by R Kumar, V Singh, K Devi, M Sharma… – Food Reviews …, 2008 – Taylor & Francis
Effect of flower structure and flower colour on intrafloral warming and pollen germination and pollen-tube growth in winter flowering Crocus L. (Iridaceae) by H Kerndorff, E Pasche – 2006 – zobodat.at
Effects of temperature on the growth of spring ephemerals: Crocus vernus by J MCKEE, AJ Richards – Botanical Journal of the Linnean …, 1998 – academic.oup.com
Plate 342. Crocus kerndorffiorum by MA Badri, PEH Minchin, L Lapointe – Physiologia Plantarum, 2007 – Wiley Online Library
The genus Crocus (Liliiflorae, Iridaceae): life-cycle, morphology, phenotypic characteristics, and taxonomical relevant parameters by B Mathew – Curtis’s Botanical Magazine, 1998 – Wiley Online Library