We tend to press the limits and this year our jade trees
suffered as a result.
We left them out too long into the fall -- they were too cold
for too long one night. The following morning we noted the leaves
were dark and watery. Imagine lettuce gone old or impatiens thinned
out after the first frost (below). That's what we saw.
Here's what we learned, and did.
Tender impatiens teaches us the signs
Below: Impatiens still might pass a cursory inspection after
the first frost...
...but look closer and you'll see
water-soaked dark spots on the leaves
where cells iced and burst.
Below: After the second hit, so many leaves have been lost
that it's just a stemmy mass. All that's left are the lower leaves
that were protected by their fallen comrades.
Above, right: Sometimes cold damage can be almost pretty.
Many hostas gradually change color in fall until one night when the
cold finally penetrates to the leaf bases. The cells there ice up,
burst and the next morning the hosta's a heap. Color change ends
because the leaves have been effectively cut off.
Jade's tough but cold's tougher
Jade can take more cold than an impatiens, but a limit's a
limit. In this case, both our jades were under cover of the porch
roof, one closer to the open air than the other. One looked like it
would lose all its outer foliage but keep the interior and lower
leaves. The plant more exposed to the night air, had damage on all
its leaves. That meant its branches had taken a hit, too.
It can be hard to tell right way when a jade's branches die. We
just hoped the trunk hadn't been hurt.
(Just how much cold can a
houseplant take?
Say thanks to a fellow reader who Sponsored us to
help us post Growing Concerns
680.
It lists minimum temperatures for
major indoor plants.)
Symptoms are subtle at first
Where's the picture? No use taking one. In the overall, they
still looked okay. What we saw was the off color of the foliage,
and that they felt less firm.
Right: On the left in this picture, a branch with
cold-damaged leaves. On the right, survivors.
It would be days before they'd start to wither, a week before
they'd be a pukey moist brown (below, right), and two
weeks before they'd be dry enough to drop off.
The plant that had a bit more
shelter than its unfortunate
buddy -- in fact, its companion's
canopy had been part of its
protection -- stayed that critical
degree or two warmer. That was
enough that many of its inner
leaves survived where the tree's
own outer layer of leaves trapped
some warm air.
Drastic measures:
No saving that limb
We cut them back -- this one severely. That was 4 weeks ago. We
crossed our fingers. Both are now recovering, pushing out new
shoots.
Here is what we mean about not being able to see the damage
to jade branches right away. When we cut back, we were guessing how
far the cold had penetrated the crown. Now it's clear that we
missed one branch. There's a crease on the limb (arrow) that has no
sprouts. That's developed as it's begun to pucker. It's
drying, having been cut off internally. It would eventually wither
away. We'll cut it back.
It will be a year before they're back to cat-hosting status,
though. Sorry, Olive! (Click Water, fertilize indoors in
March in the links at the bottom of this screen, to follow
this jade's progress.)