Last week as I was scouring our backyard for signs of spring, I was pleasantly surprised to notice a tiny, inconspicuous purple flower popping up all around my house, seemingly at random. Since we just moved to this property last summer, I’ve not experienced a full year to observe all the plant life that comes with it.
The tiny, solitary flower I noticed had not opened entirely yet, but it was undeniably identified by the white strip down the middle of its slender, grass-like leaves that characteristically emerge prior to the flowers. It was snow crocus (Crocus sieberi).
These minute, yet beautiful flowers are scattered about my lawn and garden beds across our south-facing backyard. They seem to love to pop up in the most random and peculiar spaces, with a sparse population of these very early spring flowers making an indiscreet appearance last weekend that grew to an unmissable display as each tiny flower has fully developed over the course of the week. What a wonderful surprise and nice bonus to a yard that already has inherent natural beauty, bordering the untamed and extensive bottomland forest of the Sangamon River floodplain.
Crocus is by far the first thing to bloom in our yard this spring. Ahead of the forsythia that has started to wake, but hasn’t produced its yellow flower pedals yet. Silver maples are starting their display, but also are behind the crocus as their miniscule, bright red flower structures have not quite fully formed. Crocus is truly is a harbinger of spring for our yard.
So, how did this beauty of spring wind up randomly dispersed across our yard? They have come to occupy my yard (and many others in North America) through a process called naturalization. Although snow crocus are native to the Balkan Peninsula in Europe, our area provides a climate, soils, and other factors that are also favorable growing conditions for this non-native plant. In fact, following human introduction of crocus as an ornamental plant, it has been able to reproduce naturally in much of the United States, spanning USDA Plant Hardiness Zones 3 to 8. There are over 30 species of crocus cultivated as ornamental plants in the US.
By definition, naturalized plants are non-native plants that are introduced to a new geographic area and are able to grow and reproduce without human intervention, but do not threaten our native ecosystems due to invasive habits.
Crocus is known for its ease of naturalization in lawns and gardens, spreading though self-seeding or vegetatively underground. Although crocus are commonly referred to as a bulb, this plant actually grows from a structure called a corm. Corms are similar to bulbs since they are underground plant structures that are swollen with stored energy, but differ from bulbs in that they are not layered. For comparison, consider the layers of true bulb, such as an onion. A corm is a solid structure and does not contain the various layers that are characteristic of bulbs.
Crocuses are fairly easy to establish in your lawn or garden beds, as a fall planting, similar to other bulb-like species. They require well drained soil and full sun to partial shade. However, fun sun is typically abundant during their portion of the season as trees have not leafed out. They work wonderfully under a large shade tree, in sparse turf grass or a mulched shade bed. The really nice thing about this plant is that it completes its annual growth relatively early in the season and allows for other plants to quickly steal the show as the growing season progresses. Once the crocus leaves begin to yellow (in the next month or so), you can snip or mow them with no effect on the plant. They will happily come back next year for another early spring display.
Spring will certainly be a wonderful time for discovery as plants around our property begin to wake up and many put on their spring flowering display. I am excited to see what additional surprises this spring may bring.