A variety of crocuses in southern Germany.

As we are entering April, the days are longer and slowly but surely becoming warmer as spring ushers in. That means it’s the perfect time to learn more about crocuses! Similar to snowdrops, crocuses can emerge from the cold, snowy ground bringing hope for warmer days ahead!

The genus Crocus of the family Iridaceae (Iris) comprises 85-100 species [2,3]. With a native range covering Europe— particularly the Mediterranean— and Western Asia, crocuses are not native but can be found in North America, especially in gardens as an ornamental perennial plant [2,3]. “Crocus” is the middle English word for “saffron plant” because saffron is the dried stigma and style of the Saffron Crocus or Autumn Crocus, Crocus sativus [2]. The stigma and style are parts of a flower’s female reproductive system; specifically, the stigma is the waxy or sticky receptive tip at the center of a flower which receives pollen, and the style is the extension which leads to the flower’s ovary. Interestingly, crocuses are sterile and thus asexually reproduce through self multiplication; yet, we value their stigma and style as the valuable spice saffron.

Crocuses are well adapted to cool or cold winters, precipitation from the autumn to spring, and warm, dry summers. They actively grow from autumn to late spring, being able to survive summer droughts with belowground growth [3]. The underground growth of crocuses is called a corm. Corms occur in many plants and are very similar to bulbs, but corms lack the layered scales that are characteristic of a true bulb. Corms are typically flat to slightly round with roots sprouting from its base and membranous to scaly leaves growing upwards. Also similar to rhizomes or tubers, corms are specialized sections of the stem, storing nutrients for surviving the winter and next year’s growth and facilitating a unique adaptation for asexual reproduction. As the crocus grows, more corms develop, growing into leaves and possibly flowering; older corms will eventually decompose, returning nutrients to the soil [4]. Many crocus species flower and grow aboveground with autumn rains, whereas other species may bloom without leaves and instead delay leaf production until warmer temperatures, typically in the spring [3]. There are approximately 90 species of deciduous, perennial crocuses that bloom in the early spring [2].

If you’re interested in adding some color to your spring garden, crocuses are a great option. On cloudy days or at night, crocus flowers often close, opening up with the morning sun [2]. Reaching 2 to 4 inches tall, their blooms can be a wide variety of colors— purples, blues, reds, pinks, yellows, oranges, and multi-colored— which brighten an otherwise bleak wintery surrounding [1]. Crocuses grow well in full sun to partial shade and well-drained soil, with sandy loam containing compost being ideal. Since they require an extended cold period to bloom, it is best to plant crocuses in the fall before the ground temperature dips below 60°F and several weeks before a hard frost (typically in September or October) [1]. Plump, healthy corms can be separated and replanted about 2.5 inches deep and 2 inches apart, with 35-70 corms per square foot [2,4]. Although crocuses are not native, they are typically non-aggressive and are not considered an invasive species as they generally do not overtake and disrupt the natural, local ecosystem [5]. In fact, crocuses provide a food source to bees and other pollinators in the early spring months. While crocuses may also serve as food for mice, voles, and squirrels, they are resistant to deer [1].

I hope you take the time to appreciate these spring days, whether it is one of sunny warmth or spring showers. The flowers will only continue to pop up, adding color to our days, and perhaps you will see some of the bright, bold blooms of one of the earliest spring flowers — the crocus.

Sources:

[1] https://www.almanac.com/plant/crocuses

[2] https://plants.ces.ncsu.edu/plants/crocus/

[3] https://journals.lww.com/aayu/fulltext/2010/31030/botany,_taxonomy_and_cytology_of_crocus_sativus.20.aspx

[4] https://www.gardeningknowhow.com/ornamental/bulbs/bgen/what-is-a-corm.htm

[5] http://www.gardening.cornell.edu/homegardening/scene0ab0.html

Written by Faith Forry — March 26, 2025