[LittleYellowBird]

OMG, I never thought of that. You raise a good point. And the govt/big corporations could possibly use drones (which weren’t around in the viet nam war).
Maybe drones can be kept away by netting stretched across the garden plot, such as the nets used for keeping birds off your fruit trees and berry bushes? but as for the covering against a windborne powder and such… Ya, I think your idea of the plastic coops or greenhouses is best.
A walipini is what I want… i think any way the base is, whether coop hoops or walls etc, the plastic might need to be such that you can fold or roll it back to allow for rain or warmth or sunshine…. Maybe keep the plastic on most of the time and just roll it back on random days? somehow have to allow pollinators to get in there and do their work. If the plastic isn’t all the way down to the ground, but more like a roof, would the pollinators find their way to the plants?