Frost After the Freeze

On Saturday, January 1, 2022, it was 78 F. The next morning I awoke to a garden at 26 F. Brrrrr! Shorts and t-shirts one day; leggings, layered jackets, cap and gloves the next!

The first thing I saw when I walked into the front garden was a hummingbird zooming past me heading straight for Mexican Honeysuckle. Unfortunately, the orange flowers were freezer-burned and the poor little bird, after trying several blooms and clearly not finding any nectar, flew off to find his breakfast. My SIL ambled over I and pointed to the hummer and suggested she put out her hummingbird feeder so the hummer could get its energy drink.

After this freeze, there’s little for pollinators. Hello winter! Sunday was a cold, windy day and it was clear that most perennials in the garden would have some freeze damage, time would tell just how much.

By Monday morning the wind had died down, but it was another very cold day, 26 F, a hard freeze. What brought me into the garden so cold and early was the appearance of the frost sculptures of Frostweed, Verbesina virginica. So named ‘frostweed’ this particular plant is known for its elaborate ice sculptures along the stems, caused by the first hard freeze of a season. The sculptures develop when water in a stem freezes and expands, breaking through the stem’s epidermis. As the water moves up the stem, it freezes into thin, fragile ribbons. The curls of ice that develop are delicate and can be quite elaborate, though I thought this year’s ice show was a bit restrained.

Frostweed produces substantial ice sculptures along its main stems, but it isn’t the only plant to rock these ice designs. On Sunday morning several perennials burst outward in icy winter performance art.

Firecracker Plant, Russelia equisetiformis:

Lemon Rose Mallow, Hibiscus calyphyllus:

Behind the frostweed, the stems of Barbados Cherry, Malpighia glabra:

The destruction of these stems means that a complete pruning to the ground is now required. The stems that grew during the year are permanently damaged and new spring growth will come from the roots. If the freeze wasn’t so hard, the plants might have suffered some freezer burn (like the aforementioned Mexican Honeysuckle), but not the bursting of the plants’ frozen pipes, effectively killing the plant above the ground. These plants are hardy, at least to 8F, so they’ll come back with warm spring breezes and longer days.

What I found interesting is that the ice sculptures happened on Monday, the second day of the freeze, not on Sunday, the first day of the freeze. Typically, it’s the first hard freeze that produces the ice sculptures. Best guess? I think because our fall and early winter has been very warm, the ground temperature prevented the stems from freezing that first night/morning, therefore there was no breakage and no ice. By the second morning, warmth from the soil had dissipated and all bets were off–it’s ice art all around!

The winter gardening chores are now set: raking and shredding of leaves, most of which go into the gardens, the rest into the compost; pruning of perennials, which is a weekly chore through February, and cleaning the pond which will be a very long, stinky day, indeed!

Frost Again

A few weeks ago I wrote about the whimsical ice art produced by FrostweedVerbesina virginica, typically revealed by the season’s first hard freeze; you can read about this winter’s ice art unveiling in my garden here.  I was coldly, but pleasantly surprised this past weekend to see more Frostweed ice sculptures after Central Texas–and my garden–plummeted to 20ºF (-6ºC).

Curled and swirled outwardly from the fractured and frayed epidermis of the stems, the ice is fragile, usually melting within a few hours as the Texas sun warms.

In the shady parts of my garden, the ribbons of frost remained a testament to the chilly weekend.

Even in sun-warmed spots, the ice art endured through Sunday, mid-day.

Some years, the Frostweed ice capades never materialize because temperatures don’t reach the freezing point. In other years when temperatures have fallen just to freezing, but no lower, and then later a deeper freeze occurs, the sap in the Frostweed acclimatizes so that the immediate and dramatic burst-freeze-ice curl doesn’t happen. In those years, it’s just plain old un-frosty Frostweed sticks amongst the downed, brown discarded leaves until it’s time to prune the sticks and rake the leaves.

This year, with temperatures swinging wildly from 80ºF to 20ºF and back again, the Frostweed proved its worth for the winter garden–at its base,

…and at its crown.

…and in a vase.