The cherry laurels in my neighborhood are not looking good. Chinese
Euonymus and Japanese Aucubas are a bit haggard also. Where they come from,
this sort of thing just doesn’t happen. And you know the sort of thing I’m
talking about: extreme cold followed by snow followed by blustery days and
nights. Prunus laurocerasus comes from parts of southwest Asia that enjoy hot,
dry summers and mild, relatively rainy winters. Euonymus kiautschovicus
(Manhattan Euonymus) hails from eastern China, where winter temperatures
generally hover around 40°F. So there was never a need
for them to develop the techniques that keep our own broadleaf evergreens fit
for spring.
Rhododendrons, for example, reliably roll their leaves into cigars
when the temperatures dip into the low 20s F. Their pores are located on the bottoms of the leaves and the
curling mechanism protects these vulnerable undersides. It also allows them to
conveniently shed any leaf-loads of ice and snow. You can tell the temperature
just by watching the rhododendrons; when it warms up to about 32° again the leaves
flatten, no harm done. Wouldn’t it be dandy (or should I say handy) if our own
bodies had a similar maintenance system?
 |
| You can tell the temperature by the rolling of rhododendron leaves. |
But no, we
are more like the cherry laurel and the Manhattan euonymus. When water evaporates
from these broadleaf evergreen leaves faster than their roots can replace it—which
tends to happen when the ground is frozen solid—cells die. Leaves turn brown. Plants
turn ugly. It’s their version of human frostbite.
 |
| Ewww-onymus |
Our
response to those same cold temperatures starts with the narrowing of blood
vessels in exposed body parts. If this goes on long enough, blood flow
to extremities drops and tissue dies, fingers and toes and nose tips being,
relatively speaking, expendable.
Of course we have mittens and boots and down-filled jackets,
and in fact we can make use of this bundling up concept to protect our tender
visitors from rude extremes of weather. We can swaddle them in burlap or spray
them with an antidessicant or, like the Staten Island Italians used to do to harbor
their figs, build linoleum towers.
We could also choose to plant only natives that are adapted
to the weather, but this feels rather hypocritical. We go to extreme trouble to
make all kinds of adaptations to our living conditions for the benefit of our
fingers and toes (like extracting stuff from 10,000 feet below the soil). It
seems only fair to make the habitat suitable for our guests when things turn
nasty.
The good thing is, the ugliness of cherry laurels is only
spring-deep. Unlike our cold-blasted extremities, their damaged parts were
destined to fall anyway, eventually, and will be replaced with fresh new functioning
parts.
How convenient for them.
