Despite chill in air, thistles begin slow awakening for spring | Harrison

The botanical pause of winter is monotonous in its consistency. Each day, with very few exceptions, is just like the one before it, with plants in suspended animation. 

February brings the first inkling of the burst of activity coming to Leon County which will soon arrive with vigorous growth and riotous color.

One herald for the landscape’s eruption is the awakening of thistles, native weeds entwined with many cultures reaching into antiquity.

History and the thistle

Throughout history thistles were used in folk medicine. Roman naturalist, philosopher and military commander Pliny the Elder believed thistles, with their thorny mane, to be a cure for baldness. Other early herbalists considered it a treatment for the plague, vertigo and headaches.

The most likely verifiable and legitimate use for thistle in the distant past was as an early warning system. Over a thousand years ago an invading Viking force was attempting a surprise attack on Scotsmen, when one of the barefoot Norsemen stepped on a thistle.   

The shrill reaction to the sole-piercing spines alerted the Scots who were able to successfully fend off the invaders, at least from this encounter.  The appreciative Scots incorporated the thistle in their national crest, where it remains to this day.

Florida thistles

While the lush green leaves appear as an enticing target for livestock and wildlife which seek any new foraging opportunity during the fresh food dearth of winter, they are not appealing after the first nibble. Unfortunately, at least for the herbivores, thistles are covered with sharp, stiff spines which would make consumption and digestion excruciating.   

There are at least nine different species of thistle in Florida which include tall thistle, Leconte’s thistle, swamp thistle, Nuttall’s thistle, purple or yellow thistle, bull thistle, and Virginia thistle. They are distinguished by their flower’s color and the general shape of the plant, but several are rare to encounter.

All Florida thistles are biennials, except for Leconte’s thistle which is a perennial. Biennial plants are those growing from seed in the first year and which produce seeds the second year.

Stages of life

There are three distinct life stages pertaining to all native thistles. During the first year, the plant will grow as a rosette, a taproot with a cluster of leaves on or near the soil surface. The rosette growth stage occurs primarily during the winter months in panhandle Florida.

During the second year, a stalk with a bloom bud will elongate from the rosette, which is referred to as bolting. Bolting frequently begins in late January and goes through July, depending on the species and environmental conditions.  

Once the biennial plant flowers, it can produce up to 4,000 seeds per plant.  The tiny seeds are dispersed by wind with the aid of thistledown, a soft feathery material easily transported on the breeze. As the seeds are scattered, the biennial thistles are dying.

Spring awakening

In early spring thistles aggressively emerging while many other plant species are dormant. Only a relatively few local plants react positively to the unforgiving cold nights by getting a botanical jumpstart on their competition.

The head start gives the thistles a major advantage for colonizing new ground and pushing out competitor plants when the warmer season arrives. The Cirsium species, as thistles are botanically known, also serves as a host for countless local pollinators, but also to horticultural pests and as a botanical disease reservoir. 

Whether viewed as good, bad or just painful, the thistle’s awakening has begun. The reprieve from landscape repetition is ending in the weeks and months to come. 

To learn more about this beautiful spring biennial in Tallahassee, Fort Braden and Leon County, contact the nearest UF/IFAS County Extension Office. To read more stories by Les Harrison visit: Outdoorauthor.com and follow me on Facebook.

Les Harrison is a UF/IFAS Wakulla County Extension Agent Emeritus.

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