What Is Happening To Our

Rhododendron Leaves?

The photos show the unique behavior of the leaves of rhododendron when it gets cold. These leaves on the North side of our house were reacting to the 16 degree temperature that arrived yesterday morning.

When the temperature drops below 35F, rhododendron leaves begin to cup and curl at the edges. At 25 degrees F, the leaves curl so tight that half the leaf surface disappears and the leaves droop. When temperatures hit the teens, leaves shrivel even tighter, turn brownish-green and dangle like stiff string beans. This response to temperature changes is a rhododendron's method of preventing loss of moisture through the leaves.

The upper side of a rhododendron leaf is leathery. The bottom side is dappled with tiny air valves that control the flow of air in and out of a leaf. Cold air contains less moisture than warm air. So when low temperatures and high winds arrive, the leaf valves close. By looking out a window on a winter day, one can determine roughly how cold it is by the degree the rhododendron leaves have curled and drooped. When temperatures rise, the leaves open again. The rhododendron makes the same response in summer when temperatures become excessive; only the leaves curl upward to prevent undue moisture loss.

I also took a few minutes to photograph ice crystals on our van. As you know, I think these structures are so beautiful and are, indeed, delicate and temporal. Here are a few examples courtesy of the cold surface of our Grand Caravan.

While we are in the midst of a cold snap, Sarah, Jeff, and Sammy are enjoying 80 degree weather! Yes, they are spending Thanksgiving week at the Paradisus Riviera in Cancun, Mexico. Photos below are a few pics of where they will be spending seven days.

Tis so sad that Sammy did not see the curling of the rhododendron leaves or ice crystals on the van. I hope the tropical beach experience can make up for the loss! (chuckle)