“Eden”, a company that markets vegetables to the kosher market, ran an ad in Jewish newspapers that reads in part:
“Cauliflower, broccoli, and many other vegetables are home to tiny insects that are nearly invisible to the untrained eye, and are quite impossible to remove. That’s why Eden doesn’t just try to get rid of insects; we keep the insects out, from the moment of planting.…
“Eden keeps insects out by growing its vegetables in greenhouses… So if you want to keep the food in your home truly kosher, trust the brand that has… a greenhouse –that keeps the tiniest intruders away.”
Now this is an advertisement, not a halachic ruling, but much like pre-washed vegetables, I can see greenhouse-grown vegetables becoming a widespread convenience bought “just in case;” then a communal norm; and finally a standard to be kept without which the vegetables may not be eaten.
And so Orthodoxy becomes ever-more restrictive. Here’s hoping I’m wrong.