AMONG THE MANY things I'll never understand about this country is why we import millions of migrants to pick our groceries at the same time that we can con untold thousands of upper-class Americans into doing exactly the same work and have them pay for the privilege. There hasn't been such a scam since Marie Antoinette romanticized frolicking with sheep, the most loathsome animals in the barnyard, with the possible exception of geese. We're talking pick-your-own-vegetable farms, a be-your-own bracero program for the urban elite. Now I've never been to one, but I have been dragged into my wife's garden and I want to tell you what I discovered. The sucker is hot. The miracle of agriculture is that tomatoes don't come off the vine stewed. A cornfield is the veritable invention of the devil. Know why the John Deere 7700 combine was invented? Because you can't air-condition the back of a mule, that's why. Why doesn't this register with people who want to stuff their fretting progeny into a car and drive two hours to drip their own sweat onto a couple of pints of string beans? I just don't get it. Studies of illegal Mexican immigration into America keep showing that our southern brethren don't stay in our fields any longer than they have to. They need the money bad, but as soon as they get it, most of them head back home because rockscrabble central Mexico looks a lot better to them than the conditions in California. What's the attraction to spending a day bent double lugging a heavy crate under a sun that would be infinitely more pleasant over Rehoboth? Especially if all you've got to show for it at the end of the day is a load of spinach? You know what a farm is? Gritty. Except when it's full of mud. A Wyoming farmer just found oil on his property; know what he did with his first royalty check? He paved the barnyard. This is the response of people who get to live on farms. And they want us to pay for the privilege of playing in the dirt? Then there's bugs. If you're into picking your own vegetables, you're probably one of these ecofreaks. Are you aware of one of the most popular organic pest controls? Wasps. And, of course, all this plant life won't reproduce without -- bees. Have you ever gotten on a first-name basis with one of those thick, squishy, vile, green tomato worms? Why are you doing this to yourself? Okay, let's assume that you're allergic to the plastic that supermarkets provide for produce. What's wrong with farmers' markets and roadside stands? Let those suffering souls eke out their meager income hacking their way through the rutabagas five times a day so they can deliver them to you still quivering. Just hit the button and power down the car window quickly enough to pay the man without letting all the conditioned air out. Do your bit for the agricultural economy without looking like a chump with sweatstains down to your waist. After all, the agricultural economy is what pick-your-own is all about. In the early '70s, real farmers noted that they could sell 10 acres of their worst hard-pan at outrageously inflated prices to the pampered sons and daughters of wealthy industrialists who had this thing about going back to the land. The next trick they learned was to park their tractors, turn off their diesel pumps and open their fields to liberals feeling guilty about living in the city. The suckers would pay to romanticize the harvest, gritting their teeth through the pain, and the farmer could spend December, January and February in the Bahamas -- instead of just January. The only argument I can see for pick- your-own is tha in a daiquiri at your favorite, civilized, air-conditioned, urban tavern?