#64, March 21, 2001
Argus Columnist Bill Soberanes years ago wrote,
"Writing about my tomatoes brings more reader reaction than when I write
about any other vegetable." [note to Chris: we have the clipping on our
refrigerator!] With the buds of spring freshly opened, let me tell you about my
family's vegetable garden.
I'll confess that most of the stuff we plant struggles to a
mediocre performance-- with two exceptions. First are the tomatoes, and
especially Early Girl. Early Girl earned a permanent place in our garden when
my now-adult daughter was but three. I pointed to two plants and said,
"this is Early Girl, and this is Better Boy." Feeling her emerging
feminism, she shook her head, pointed to the first plant, and said, "No,
this is Better Girl!"
Our "Better" Girls grow like jungle weeds
("need a flame thrower to keep them under control", says my wife.)
They rise as high as there is concrete reinforcement wire cage to climb, and
when the cage ends, they spill back to earth and sprawl. Roots spread out as
far as eight feet, sustaining dozens and dozens of tennis ball size tomatoes
(ahhh, autumn…!)
But Russian Kale wins the prize. It's a strangely beautiful
plant, dark green with an eggplant violet blush. The leaf margins are dissected
into flowing art noveau lobes. Many leaves have weird miniature leaves growing
from out the middle. It's beautiful, has the best nutrition of any green
vegetable, and cooks up tasty in a soup or stir-fry. Left alone, it can live
two years, scattering seed for the next generation, producing a stalk nearly
thick as your wrist.
On one of those sweet still winter afternoons, we sat on the
edge of a raised bed, admiring our dozen baby kale plants. The snails had hit a
few of the runts pretty badly, but they all looked like they'd make it to
adulthood. I wondered, why do the snails go after the weak plants? You can
understand why the wolves attack the sick caribou versus the alpha male. But what
is a healthy kale plant going to do, crack the snail with a whip of it's stem?
Are the weaker plants easier to chew? Maybe the weak ones,
whether damaged in transplant or genetically inferior, just happen to break
down in a way that makes them more appetizing to predators. But why would they
do that? What advantage is there for them, or their species, to become tasty
salad for snails?
Imagine you are Raphanus, the wild radish ancestor of
Russian Kale. You've got to create viable descendents, to carry on the family
line. Unlike the oak, you've only got a year or two, so you make lots of seeds.
Most are eaten by birds, bugs, or bacteria, but a good crowd of them sprout.
They grow well, which is good. But then they start to crowd each other, which
is bad-- if they keep crowding, they all suffer, along with seed quantity and
quality.
So then along come the herbivorous predators, mowing down
the weaker plants. Not only are the weaklings removed from the competition for
light/nutrient/water, their bodies are recycled as fertilizer for their
surviving kin. But how do these predators find the weak ones? They seem to know
without having to taste everything. Are the suicidal sacrificial radish plants
sending out signals, chemical temptations for the snails' antenna. Have the
radishes and snails co-evolved a biochemical call and response partnership,
designed to strengthen the DNA durability of both radish and snail?
The wild radish and the Russian Kale weren't always the way
we know them. They evolved up from monocellular ocean critters, along one of
the bazillion multibranching paths leading to every living creature on the
world today. At some point along the way, the radish ancestor may have
"learned" how to respond to stress by producing chemicals that
attract snails. How? And how did it determine and stay current of the interests
of snails as they evolved. A hundred million years of trial and error? Some
form of universal intelligence? Reader reactions, anyone?