Thursday, February 19, 2009


February’s fluctuating temperatures have been giving my rhododendrons a workout. Have you noticed this fun little botanical phenomenon—that you can tell the temperature by the angle of your rhodies’ leaves?

The first time I saw my rhodies curl up for the winter, it scared me to death. I thought I had lost them all. But now that I know what’s going on, it’s fascinating to watch their slow-motion dance. (There. You now know just exactly how dull my life is!)

When temps are above freezing, they kick up their leafy heels at almost a right angle to the stem. Here’s one of mine on a recent 40-degree day:
rhodo 40 degrees b
Just below freezing, the leaves begin to droop (much like me on a cold, sunless day!).
Below 25 degrees (it was 15 here today when I took this next photo), the leaves dangle almost straight up and down, and curl lengthwise till they look like bean pods or little green straws. Besides preventing moisture loss, this also protects the plant from sun damage while the bare deciduous trees provide no shade.
rhodo  below 25
Rhododendrons and azaleas can be a little tricky to grow here in zone 5, but there are a number of varieties that do well in our colder winters, including PJM, Girard hybrids, and the “Northern Lights” series.

The two in these photographs are catawbiense varieties, my own personal favorite. (They’re also recommended by Ezra Haggard in his book,
Trees, Shrubs, and Roses for Midwest Gardens, which is where I found the comforting news that my curling rhodie leaves were nothing to worry about.)

These two rhod0-mometers are in my front foundation bed, which I’ll tell you more about in my next post. Stay tuned—and stay cozy and uncurled in the meantime!


  1. I have noticed mine drooping too, but never like your third picture! We don't usually get weather that cold. It'll be nice to see them warmed up and in bloom won't it?

  2. Hi, Sheila--
    The plant world never ceases to amaze, does it? Always something new and interesting to observe. Thanks for visiting!

    Hi, Catherine--
    I'll bet my rhodies would love to pick up their droopy skirts and trot over to join yours! But it won't be too much longer now till it's nice and toasty around here.

  3. Hi Donna, thanks for stopping by to visit my blog today. I love discovering new garden blogs, especially in the Chicago area. I've added your blog to my sidebar in the list of Chicago-area/Illinois blogs.

    I hope you're thinking about attending Spring Fling!

    I'll be looking forward to seeing those rhodies in the spring.

  4. Hi, Garden Girl--
    Thanks for the link on your blog. That's one thing I still want to do on my blog as well--add a list of some of my favorites. Little by little... Spring Fling sounds wonderful. I'm still not sure if I can come or not. Maybe I'll see you there!

  5. Aren't rhodomometers great, Donna? Mine aren't quite so offended-looking today, but on the real cold days they haul down and roll up their leaves and just plain look irritated. As the snow gets deeper and deeper around here, I look just plain irritated too! ;-) Thanks for visiting and leaving your comment, and i"ll be back again soon.

  6. My pleasure, Jodi! Nice to have a little diversion on a cold and blustery day, eh? I mean, you can only watch rhodies for so long, as intriguing as they are! :)


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