Dawn of the dead

A lethal night gave way to the dawn of the dead.

That could be the byline for a horror movie starring cold-sensitive plants, and that’s exactly what happened last night.

Typically, when we have frost, it’s for a few hours around dawn. But last night we hit the 32°F mark at 11p.m. and we were below freezing until 9 a.m. this morning (the low was 26.7°F according to Weather Underground.) That’s 10 hours of frost, and that’s bad news for many of our tender plants, not to mention our citrus crop. It’ll take a few days to get a definitive picture of what is damaged, but one thing is clear already: This was the most brutal night of this winter. (Yes, I know we’re all “sensitive petals”, as our Australian friend Bill would say, but we can’t help it.)

The succulents I’d covered with a frost blanket appear to be OK, as are the potted plants on our front porch. But there are still casualties; with any luck they will recover in time.

Variegated Eureka lemon in the front, yellow lotus banana behind it. Some of the leaves on the Eureka lemon don’t look good, especially the tender new growth. There are quite a few flower buds as well. Not sure what will happen to them.

Yellow lotus banana (Musella lasiocarpa). It looks terrible but it’s actually hardy to 10°F. It will grow new leaves as soon as we have consistently warm weather.

Giant elephant ear (Alocasia macrorrhizos 'Borneo Giant'). The leaves are toast. I’m frankly surprised they lasted as long as they did. The tubers are hardy to zone 8 and will produce new leaves in the summer as soon as the soil temperature is consistently above ~60°F.

Euphorbia ‘Helena’s Blush’ (Euphorbia amygdaloides hybrid). It is supposed to be hardy to 0°F. No clue why it collapsed like it did.

Our calla lilies (Zantedeschia aethiopica) look very droopy. Last year I covered them up but still lost about half of the leaves. They’ll bounce back fairly quickly once it gets a little warmer.

Large Agave chiapensis with frost damage (dark spots). Hardy to 28°F. I should have covered this one up; that’s what I did last winter and it sustained no damage. This is just cosmetic damage, but agaves don’t exactly grow fast so the plant will be disfigured for a while.

Agave celsii, supposedly hardy to 20-25°F. This one is in a pot in an exposed spot on our front porch. All I had to do is move the plant to a more sheltered position to protect it…but I didn’t. The dark spots are damaged tissue. This isn’t lethal but the leaves will be pock-marked.

Tower of jewels (Echium wildprettii). Endemic to the Canary Islands and supposedly hardy to 20°F. Too soon to say if there’s any real damage. I lost one of these stunning plants last fall for no apparent reason.

Our bamboos are OK even though these two sub-tropical Bambusas had quite of a bit of frost on their leaves.

Baby blue bamboo (Bambusa chungii ‘Barbelatta). Hardy to 21°F. Some leaves have had a yellowish cast for a few weeks now and may fall off soon. No cause for worry, the plant itself it fine and will grow new leaves in the spring. The culms are unharmed.

Giant clumping timber bamboo (Bambusa oldhamii). Hardy to 21°F as well. No damage here, but this is the first time I’ve seen this much frost on its leaves.

Most perennials in our garden aren’t fazed by a low of 27°F. They keep on trucking as if nothing had happened. In fact, frost makes their leaves extra beautiful, especially since it’s so fleeting.

 

 

Citrus trees and fruit are fairly sensitive to frost. I checked our Washington navel orange tree, which is full of fruit, and it looks unharmed. I picked a couple of oranges and they tasted fine, but that doesn’t mean much at this stage. It’ll be a few days before frost-damaged fruit begins to turn mushy and lose its flavor (that happened last year).

Some experts recommend picking frost-damaged fruit as quickly as possible and juicing it right away in order to preserve the flavor. I’m not sure yet what we’ll do; the optimist in me hopes that most of our fruit had enough protection from overhanging branches and is OK. We’ll reassess tomorrow.

Readers in the citrus belt: Farmer Fred, a well-known Sacramento-area master gardener with a weekly radio show, has some useful information about citrus protection on his website. Read this and this.