Tag Archives: frost

Fall Frost Flowers

Fall is not my favorite time of year. Yes, the leaves are beautiful in their many hues. Yes, the cooler temperatures are a welcome respite from summer heat. Fall frost warns of cold moving in.
For me fall makes it hard to enjoy walking in the woods. I love the green plants and colorful flowers. I love warm air and not wearing layers of clothing plus a coat.

frosted gallium leaves

This gallium plant has its leaves edged in white frost lace.

Frost means dead plants, bare trees and slippery paths covered with dead leaves. Definitely a time to sit inside near the wood stove.
But frost has its attractions too. Killing frost has a special attraction.

leaf edged in frost

Each delicate lacy leaf lobe has its frost edging.

Hard frost freezes the dew on anything. In freezing the dew becomes little spikes edging leaves and leaf veins. They form delicate traceries on plant stalks.
Such frost pictures are common all winter. One isn’t.

seed head with ice spikes

Ice spikes fuzz out from the beggar lice in this Queen Anne’s Lace seed head.

The first real killing frost, the one down in the low to mid twenties, brings out the frost flowers.
The wild mint dittany is a reliable plant to make frost flowers. White crownbeard does too but grows along the road where the sun shines early in the day. Dittany is up in the woods.
Frost flowers last only a short time. The air must be cold. No hint of sun must touch these ice creations. No wind must go through to break their delicate ribbons.

frost flower

Dittany stems still have water in them when killing frost hits the Ozark hills. The water freezes splitting the stem allowing the ice to ooze out in an ice ribbon forming a frost flower.

The temperature was twenty-five degrees at dawn. Perfect.
Frost laid heavy on the ground so there was no wind. Perfect.
The sun was peaking over the hill but still hidden behind the trees. The world was light enough to see easily. Perfect.
The frost flowers were out in abundance on the hills.

Fall Colors

Mention fall to most people and leaves changing into fall colors is what they think of. My part of the Ozarks is disappointing in that regard this year.

Beautiful fall colors depend on several factors. One is day length and that happened right on schedule.

Ozark road in fall

An Ozark country road winds around a bluff rock and past a creek under leaves turning colors.

Another is rain. Rain in the Ozarks stopped in September just when the leaves would stock up to put on their fall display.

Temperature seems to matter too. Usually temperatures drop in early September and flirt with freezing for about a week. The cold spell did show up but wasn’t very cold.

red sumac leaves

Sumac turns red early in the fall.

The last factor is the wind. This has been a windy year especially lately.

Fall colors show up when temperatures are too cold for chlorophyll. Most leaves start making a thick layer between their stalk or petiole and their branch about then. They start sending chlorophyll back into the branch or letting it decay in the leaf.

Colored pigments can do photosynthesis at lower temperatures than chlorophyll so the leaf makes these. Green disappears. Reds, yellows, purples and oranges appear. It takes water to make these colors.

That thick layer marks where a leaf will break free of its branch later on. It is a weak spot. Wind tears the layer loose early pulling the leaves off the trees.

yellow spice bush leaves

Spice bush turns bright yellow. This bush started but wind carried off its leaves before the entire bush turned yellow.

October is usually the month when the Ozark hills are painted in fall colors. I was watching the far hill start turning.

One morning the green on the hill becomes yellow green. The yellow increases until the hill is covered with yellow hickories and dusky red oaks.

The yellow tinge began on schedule. The wind tore through. Instead of yellow and dusky red there is the dull gray of bare branches usually reserved for November with patches of fall colors trying to show off.

green sycamore leaf

Light frosts encourage leaves to turn color. There were no early frosts but plenty of wind so many leaves like this sycamore one are blown down still green.

Many trees still have green leaves. Several frosty nights have confused matters even more.

Light frosts will turn leaves into fall colors in a single night. There were no light frosts this year. Instead temperatures dropped into the high twenties, a medium frost but not a killing frost.

A killing frost at night is followed by a morning when the leaves drop like rain. A medium frost is followed by dead dry leaves of green or fall colors hanging from the trees until the wind tears them loose flinging them to the ground.

Fall is the harbinger of winter, not a happy thought. Fall colors at least make this palatable. Maybe next year will be better.