Things to know about Crocuses
The Crocus genus comprises approximately 75 species, primarily growing wild in Southern Europe and the Middle East. It is one of the earliest to bloom in our gardens, right after winter aconite and snowdrops. Spring-flowering crocuses are divided into botanical crocuses, wild crocus species, and large-flowered crocuses. All crocuses thrive in ordinary garden soil and sandy soil, in sun and light shade under bushes and trees, and also in lawns and naturalized areas. Bees love crocuses. The botanical crocuses, which bloom earliest and reach a height of 5-10 cm, come in many colours and varieties within the species Crocus chrysanthus, Crocus sieberi, and Crocus tommasinianus. They are followed by the large-flowered crocuses, which have larger flowers and are slightly taller, up to 15 cm. The third group of crocuses are autumn-flowering crocuses, also known as naked-flowering crocuses. They are planted in the autumn and bloom immediately afterwards in September-October. The leaves do not appear until spring. In the second year, they will bloom slightly earlier than in the first year.
Large-flowered crocus, Crocus vernus and Crocus flavus
Large-flowered crocuses have bigger flowers than botanical crocuses. They bloom in early spring, slightly later than botanical varieties. They come in strong colours: white, yellow, and blue-purple, as well as striped varieties. The most well-known are 'Jeanne d'Arc' (white), 'Mammouth'/'Yellow' (yellow), and the blue-purple varieties 'Flower Record' and 'Rememberance'. They grow to a height of approximately 15 cm.
Botanical crocuses, Crocus chrysanthus, Crocus tommasinianus, Crocus sieberi
Botanical crocuses come in many colours and grow up to 10 cm tall. They bloom a week earlier than large-flowered crocuses and are excellent for planting in lawns, for naturalising, for planting in beds, and in pots with other late-blooming flower bulbs such as daffodils and tulips.
Autumn-flowering crocuses, Crocus speciosus, Crocus zonatus (kotschyanus), Crocus sativus (saffron crocus)
Autumn-flowering crocuses should be planted immediately after purchase and will bloom shortly after. The leaves will not appear until spring. They grow to a height of 10 cm and come in light purple, lilac-pink, blue, and white.
Saffron crocus, Crocus sativus, is difficult to cultivate in Denmark. It will flower in the first year but is difficult to get to flower in year 2. Try growing it in a greenhouse. 800 stigmas are needed for 1 gram of saffron, and each flower has 3. It originates from Iran and is also cultivated in Spain and North Africa, among other places.