I don’t know about you, but when it’s cold out, I tend to pull in on myself—shoulders go up, chin comes down—it’s as if I’m trying to make myself smaller in order to stay warmer. I thought of that recently as I’ve been observing the fascinating foliage on the P.J.M. rhododendron near my front door.
As the season changes, the rhododendron has been telling me how cold it is outside each morning. On chilly days — say in the teens or 20s — the leaves of the rhododendron are turned down and rolled in, sort of like a tube. If the weather is warmer—high 30s or 40s—the foliage is in its usual flat shape.
Rhododendrons are broad-leaf evergreens. Unlike deciduous shrubs, they do not lose their leaves over the winter. The buds for next year’s flowers and the leaves hold on through most of the winter. According to the University of Minnesota, the curling action is a way to hold onto water during the dry, cold parts of the year. Sometimes curling is caused by disease, but that often happens during the growing season and this rhodie looked fine all summer long.
We’ve had a wet fall and this is a long-established shrub, so I don’t think it is struggling for water either. It’s perhaps just upset about the suddenly cold weather we’ve had! Are the leaves on your rhododendrons curling too?