Will You Need a Warmer Hat This Winter?

by Carly Brown

A few weeks ago I tied my laces, donned my hat, and set off for a long run down Spear Street, from Burlington to Charlotte and back again. Partway through my run I saw it crossing the road without any signs of hurry, proudly displaying its black and rusty fur: the woolly bear (Pyrrharctia isabella). I immediately looked up to check for oncoming traffic, then dodged out into the road, lunged, and swiped the fuzzy caterpillar. Without breaking stride I carefully set it on the roadside it was moseying to. Some feet down the road I repeated my behavior. My mind clicked back to middle school when I learned that a long rusty stripe means a mild winter. Is that true? And what are woolly bears when they are not cute, furry, caterpillars? Never mind what passing cars must think about my woolly bear lunge.

Wolly bear (Pyrrharctia isabella) caterpillar

Wolly bear caterpillar (courtesy IronChris, http://en.wikipedia.org/wiki/File:IC_Pyrrharctia_isabella_caterpillar.JPG)

The woolly bears that we see in the fall will overwinter as caterpillars under plant debris in the cold snow environment. In order to survive the winter chill, the caterpillars produce a substance, called a cryoprotectant, which acts much like antifreeze. When spring begins to show its face, the caterpillars emerge from the leaf litter, begin to eat new plant growth, and then form a pupa to eventually emerge as the Isabella tiger. This moth is a relatively nondescript yellow-brown moth with several darker spots on its wings. Woolly bears have two generations per year. This means that the newly emerged moth lays its eggs, which hatch to complete the cycle through woolly bear and moth in the summer. The eggs that these new moths lay will hatch into the woolly bears that overwinter.

Isabella tiger moth (Pyrrhartia isabella)

The Isabella tiger moth (Pyrrhartia isabella) (courtesy Steve Jurvetson; http://flickr.com/photos/44124348109@N01/501714313)

Do these fuzzy caterpillars tell us something about the winter to come? The legend is that the longer the rusty brown stripe on a woolly bear, the milder the winter. Conversely, a narrow rusty band predicts a harsher winter. There have been a few attempts to correlate the size of the stripe with winter conditions. One of the most well known studies was by biologist Charles Corran in the 1940s. For the first few years of his study, the prediction of the woolly bear was correct, but there was more than enough evidence to disprove the common myth in the years to follow. Some suggest that the length of the rusty stripe may actually tell us something about the harshness of the winter and spring that occurred the year before.

I know deep down that the woolly bear myth is just that—a myth. That doesn’t stop me from doing a few extra lunges to save a woolly bear or two and check out the length of the rusty stripe. Curious about what this winter will bring? I suggest that you join me in the woolly bear lunge.

Fern Surgery

by Carly Brown

The hand saw sits on the disinfected countertop. Fresh fern-appropriate soil waits in a bucket next to my workstation.  I wheel the ferns in on their ‘gurney’, a garden cart that I pull through the greenhouse to the office. I pass by the succulents, the lipstick tree, and finally the cacti. I am wheeling the ferns in for surgery.

As a greenhouse student employee I work in House 2 amongst the pitcher plants, orchids, and ferns. Once a week I scout the area for greenhouse pests. My hand lens is more or less permanently pressed to my right eye as I search for spider mites, thrips, and aphids (more on that in another post).  Today, however, is fern bisection and transplant day. I have transplanted before, but I have never cut plant clusters into pieces to put a smaller individual back into the original pot. The ferns have not only outgrown their pots, but will soon outgrow their area in the greenhouse if they are not cut back.

Removing the large leather fern from its pot is not a task for the weak. Its deep green, shiny, waxy-looking fronds rise up above my head as it sits on the counter. The pot is dense with secret underground growth. Using all of my strength, I flip the pot upside down and rap it against the edge of the counter until the fern slides out of the pot. Catching it in my hands, I flip the fern right side up. Intricate roots and underground rhizomes support its structure enough that it retains the pot shape. The rhizome on a fern is comparable to the stem on a flowering plant. Though it is below the soil it gives the plant a sturdy structure, much like our legs.

I grab my surgical tool: the saw. The goal is to divide this fern into four equal sections. I start the cut, putting all of my muscle into it, but the saw does not make progress. I move the saw back and fourth, but it does not go deeper into the soil. Is this possible? Am I trying to saw through a piece of metal that I did not see? My muscles strain as I push and pull – back, forth, down – until I finally feel the saw going deeper into the soil. After the saw makes it halfway, something gives. I have made it through the hard, almost woody, rhizomes of the fern, and can now detangle the more delicate roots.

Pulling apart the fern base, I am mesmerized by the beauty in the mess of rhizome structures weaving in and out of each other. I have admired ferns in the forests and fields, and have recently tried delicious fiddleheads smothered in butter.  Despite my above-ground admiration, I have never known what goes on in the life of a fern below the cover of soil.  After making a second bisection I place one section of the fern in its old pot and fill it with new soil. This new soil hides the fern’s secret – its solid, intricate, rhizomatous base. After returning the leather fern to House 2, I drench the dry soil with water to jumpstart the growth that will eventually reveal the secret to another naïve student employee on transplant day.




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