By Les Harrison
Wakulla County Extension Director
The shorter days and moderating temperatures are an accurate indication of the dormant period in the near future. Shrubs, trees and weeds are, for the most part, in a shutdown mode.
Seed and berries are ripening and ready for distribution, and leaves are fading to brown.
For homeowners the lawnmower is about to go silent for a few months.
Careful observation in the lawn reveals some counter cyclical plant activity. Thistles are greening up and are ready to thrive in the local winter.
This is prime time for thistles to start growing and become established for the upcoming spring days months from now.
The head start gives the thistles a major advantage for colonizing new ground and pushing out other plants.
The lush green leaves are an enticing target for livestock and wildlife which seek every grazing opportunity during winter.
Unfortunately, at least for the herbivores, the leaves are covered with sharp, stiff spines which make consumption painful.
There are at least nine different species of thistle in Florida which include tall thistle, Lecontes thistle, swamp thistle, Nutalls 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 and not commonly seen.
Thistles split the difference between annuals, which live a year, and perennials, which live a much longer life. These natives are biennials which live for two years.
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 Wakulla County.
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 moved on the breeze.
As the seeds are scattered the biennial thistles are dying.
Throughout history thistles have been used in folk medicine.
Roman naturalist, philosopher and military commander Pliny the Elder believed thistle to be a cure for baldness.
Other early herbalists considered it a treatment for the plague, vertigo and headaches.
The aggressive thistles give little warning to their colonizing efforts.
Once established, they spread by the thousands and grow while other plants are asleep.
Homeowners and landscape managers are usually the ones who need the headache relief from this persistent plant.