Radishes and science

Radishes and science

Photo by Skyla Design on Unsplash

Originally published 24 April 1989

All over New Eng­land spades are turn­ing earth. It’s that time of year to ask the peren­ni­al ques­tion: Is gar­den­ing a sci­ence or an art?

Around our house the evi­dence comes down heav­i­ly on the side of art. I’m the sci­en­tist in the fam­i­ly, and when­ev­er I bring my ana­lyt­i­cal skills into the gar­den the result is dis­as­ter. My non-sci­en­tif­ic spouse, on the oth­er hand, needs only walk into a room and the house­plants bur­geon in their pots. If she sticks a dry twig into stony ground the result is a boun­ti­ful bush.

But the sci­en­tist in me refus­es to admit that plump, juicy toma­toes can­not be engi­neered into exis­tence by the brute appli­ca­tion of ana­lyt­ic methods.

My dream of sci­en­tif­ic hor­ti­cul­ture was giv­en a boost when I came across Roger Swain’s new book The Prac­ti­cal Gar­den­er: Break­ing New Ground. Swain is a host of PBS’s pop­u­lar tele­vi­sion series The Vic­to­ry Gar­den. His sci­en­tif­ic cre­den­tials are impec­ca­ble. He is a biol­o­gist, trained as an ento­mol­o­gist, and sci­ence edi­tor of Hor­ti­cul­ture magazine.

Plumb bobs and protractors

Swain is one of the best sci­ence writ­ers work­ing today. His essays are grace­ful, intel­li­gent and always inter­est­ing, and the chap­ters of this new book on gar­den­ing are no excep­tion. I eager­ly culled his pages for evi­dence of a sci­en­tist suc­cess­ful­ly mak­ing things grow.

And in ear­ly chap­ters it did indeed seem that sci­ence, not art, made Swain’s gar­den flour­ish. Chap­ter one: Enough Sun­light. Swain the sci­en­tist ruth­less­ly applies Ock­ham’s Razor. “Soil, water, fer­til­iz­er — these things can be changed, but nobody ever repo­si­tioned the sun,” he writes, and gets out his com­pass, plumb bob and pro­trac­tor to chart the motion of the sun across his back­yard plot.

Now that’s the way I like to do things. Num­bers. Graphs. Degrees of azimuth and alti­tude. How many foot-can­dles of sun­light fall on each radish plant? How many hours of full sun for each toma­to? (And as I write these things I hear my spouse sniff deri­sive­ly; she knows instinc­tive­ly that our back­yard is too shady for tomatoes.)

Swain is the son of two chemists (he tells us), and expounds with quan­ti­ta­tive delight on soil acid­i­ty. I loved his chap­ter on the pH scale; it is laced with num­bers and deli­cious dol­lops of chem­istry. But at the end of the chap­ter comes a hint that chem­istry alone will not make veg­eta­bles spring from the soil. “I will con­tin­ue gar­den­ing in the soil I’ve got,” writes Swain, “which I’m cer­tain is basi­cal­ly acid, more or less.”

From that moment of equiv­o­ca­tion things start down­hill (“Uphill,” I hear my spouse glee­ful­ly retort). By the time I get to Swain’s chap­ters on seed cat­a­logs, mulch, and com­post I detect art tak­ing over from sci­ence. Worst of all, I detect the bane of the failed sci­en­tif­ic gar­den­er — the Green Thumb.

Lis­ten to our author on water­ing grass: “Ignore all the advice about when to water; ignore the peo­ple who tell you not to water at night because you will cause fun­gus, or dur­ing the day because droplets of water will become tiny mag­ni­fy­ing glass­es and burn holes in the grass blades. It rains at all times of the day, does­n’t it? I pre­fer not to water at mid­day for the sim­ple rea­son that the sun evap­o­rates some of the water before it gets to soak in. I don’t water in the mid­dle of the night because I am usu­al­ly asleep.”

Practical magic

It dawns on me that Roger Swain the sci­en­tist and Roger Swain the gar­den­er are not nec­es­sar­i­ly the same per­son. Roger Swain the gar­den­er is part sci­en­tist and part artist, part ento­mol­o­gist and part insect adver­sary, part botanist and part implaca­ble foe of weeds (“There are no paci­fist gar­den­ers.”). His head may be in the sci­en­tif­ic clouds, but his hands are grub­bing in the soil. This is not a man in a crisp white lab coat speak­ing, but a man who loves to thump the soil from a king-sized clump of car­rots or feel in his hand the heft of a humungous sum­mer squash. His les­son seems to be, “do what­ev­er works.”

OK, so I’ll grudg­ing­ly admit, gar­den­ing is not a sci­ence. Sure­ly sci­ence brings some­thing to the gar­den. For exam­ple, the biol­o­gist who knows that plants and insects have been inti­mate­ly asso­ci­at­ed for 300 mil­lion years is cer­tain to approach the prob­lem of pest con­trol with a cer­tain fatal­ism; “it is unrea­son­able to expect to have the for­mer in your back­yard and not the lat­ter,” writes ento­mol­o­gist Swain.

The best gar­den­er may be part sci­en­tist and part artist. Com­pass­es, pro­trac­tors, and pH kits won’t pro­duce prize-win­ning veg­gies with­out a touch of hor­ti­cul­tur­al mag­ic, as Swain’s book on “prac­ti­cal” gar­den­ing delight­ful­ly con­firms. And when you think of it, the best sci­en­tist is also part sci­en­tist and part artist. All the mea­sur­ing and cal­cu­lat­ing in the world won’t make a lab­o­ra­to­ry drudge into an Ein­stein. Prize-win­ning sci­ence is done by those with the sci­en­tist’s equiv­a­lent of the gar­den­er’s green thumb.

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