The Iceman Cometh: April freeze casualties

– Posted in: Plant info, Weather
7 comments

After my shrubs got planted they enjoyed a weekend of glorious weather. But I happened to notice Sunday morning that it was supposed to get in the low 30s that night. Low 30s, I knew, meant definitely below freezing around here. I made a mental note to bring in my potted plants and cover the hydrangea.

But I forgot.

Monday morning (April 17th) I awoke to 25.7 F (-3.5 C) on my max-min thermometer.

image of two potted plantsHere you see the two plants I meant to bring in. The first is a potted rosemary that I managed to keep alive all winter long. I haven’t had much better luck than Michele in bringing rosemary through the winter–until this year. This year was different, because I finally followed Judy’s advice from way back here. (Actually, we had several posts about rosemary back then, so you might want to run a search on “rosemary” to make sure you see them all.) My bedroom is the best combination of cool and bright to be found in this house, but there wasn’t room at the south-facing window until I got rid of one jade plant and put the other one on the floor. While it didn’t bloom, the rosemary did pretty well there, though the new growth was obviously leggier than what had grown outdoors last summer. And then I went and fried it with one night’s forgetfulness. Sigh.Frost damaged rosemary showing new growthFried. Scorched. Burnt. Cooked. Ever notice how many words used to describe plants damaged by cold are actually words we associate with heat? Take a good look at that rosemary above. (Click on it to enlarge.) This photo was taken twelve days after the damage was done, and you can see the bright green new growth at the tips of branches that have damaged leaves ranging in color from olive green to brown. It looks scorched, doesn’t it? But, fortunately, not killed. I debated whether I should cut it all the way back to the roots, or give it a trim. I could see new growth breaking along the branches as well as at the tips, so I opted to cut away all the leggy growth and take a wait-and-see approach with the rest.

It surprised me a bit to see the rosemary take such a hit, because Judy Miller wasn’t the only one to tell me rosemary could tolerate temps lower than what mine got that cold night. But it surprised me even more that the variegated Solomon’s seal (Polygonatum odoratum thunbergii ‘Variegatum’) that I had bought on impulse came through unscathed. Due to having been grown in a greenhouse, it was obviously much further along than if it had started the season in the ground in my garden. I had been hardening them both off for a couple of weeks, and gotten to the point where I was leaving them out all night when there was no danger of frost. Still, the Solomon’s seal seemed like the more tender plant. I took courage from its endurance of cold and have since planted it in its permanent location.

The final casualty of Jack Frost’s visit (which was typical for April in this area) was my precious hydrangea.Scarcely leafed-out hydrangea with frost damageAll those crispy brown things along the stems used to be healthy green baby foliage. It’s grown that one leaf in the past 12 days. I’m hoping that once it settles in it won’t be so precocious in breaking bud, but Don tells me that it has a tendency to get in this sort of trouble. I hope it proves worthy of the extra coddling it will apparently need.

Since that fateful night, it has gotten below freezing 4 more times. The coldest it got was 22.9F (-5C). I’ve dutifully brought in the rosemary and covered the Solomon’s seal and hydrangea all of those nights, and every other night temps below 40 were predicted. Our last frost is usually sometime between the last week of May and the first week of June, so I’ve got another month of babying ahead of me. Even if I faithfully remember to do my duty, there’s always the possibility of being thrown a curve ball, such as when the predicted cloud cover fails to materialize and the earth radiates its precious heat far away from the plants. I’ve braced myself for the worst, but still hope for the best. It beats Texas heat any day.

About the Author

Kathy Purdy is a colchicum evangelist, converting unsuspecting gardeners into colchicophiles. She would be delighted to speak to your group about colchicums or other gardening topics. Kathy’s been writing since 4th grade, gardening since high school, and blogging since 2002.

In the spring, at the end of the day, you should smell like dirt.

~Margaret Atwood in

7 Comments… add one

Susan May 10, 2006, 7:23 pm

I’m delighted to hear that the rosemary can survive such a chilly evening.

I’ve been brave/foolhardy and set out a few tender plants already … but have hedged my bets with mini greenhouses constructed of the bottom halves of several plastic milk jugs.

My neighbor had given me a few tomato seedlings in a milk-jug planter, and that gave me the idea.

No, I haven’t set out my tomato seedlings yet, though I have been leaving them out in their pot each day and most nights. (Soon, soon!) On the chillier evenings, I move them into my four-wheeled greenhouse, aka the minivan, which is where they spent their first few weeks in my care.

Kathy Purdy May 2, 2006, 7:23 pm

Bill and M Sinclair–
That wasn’t even the coldest night, just the first one. The coldest it’s gotten since I planted the hydrangea on April 13th was 22.9F on April 26.

bill May 2, 2006, 5:48 pm

I’ll second the last comment. We’ve already had some triple-digit days. Although it does sometimes still get cool enough in the evening to warrant a heavy shirt.

There are some really big rosemaries out along a country fenceline where I travel some. They are over 5 foot tall. I’ve been meaning to stop sometime and check the fragrance. Some are much more fragrant than others.

M Sinclair Stevens (Texas) April 30, 2006, 3:58 pm

25.7 degrees. Unbelievable. I can’t process it. We’re down here wiping our brow and sipping iced tea. It’s hovering around 90.

jenn April 30, 2006, 11:22 am

We had a frost come through one night a week ago, and hit pretty hard. I wasn’t watching, so I didn’t know it had happened until I went out and saw the damage. The canna lilies I put out early are probably going to recover, but I was ready to write them off. They were an impulse buy and while I have overwintered them successfully twice, they haven’t bloomed for me yet…

What made me sad was the damage to the anemone japonicas. Sigh. These are late to arrive in spring, but still show up about 2-3 weeks before our frost date. I’m thinking about rigging spring row cover to put over them when I pull the mulch, and to uncover when we hit our last predicted frost date. A bit of pampering for a favored flower. Really like these guys. Startled me to see the damage. I thought they were a bit tougher than that!

Hanna in Cleveland April 30, 2006, 9:59 am

I try to overwinter rosemary in my basement overwintering room and it never makes it. I think it is too damp. Maybe I will try rosemary cuttings in the garage this next winter, which would be much like a cool sunroom.

Sandy April 29, 2006, 6:46 pm

We have an upper level deck and I recently put out Rosemary and other marginal plants underneath on the lower patio. So far, I’ve been able to get the rosemary, artemesias and pelargoniums (geraniums) to weather the few frosts we’ve had here on the northern coast of Maine. I’ve even overwintered a Purple Wave Petunia! That’s not to say we won’t have a real “whopper” before our last frost free date of late May. But one can dream, can’t one?

I just got my order from White Flower Farm. The “Black Lace Elderberry” arrived in good condition, but looks a bit droopy. I watered it well, but think I will take a snip and see if I can get it to root. Any advice out there?

Leave a Comment