It was hardly worth the trouble. I've never had that kind of bad luck. Our neighbor poured Round Up along our fence on his side, where we had also planted our tomatoes. At the time, our tomato plants were about 2.5 to 3 feet tall already, but not producing yet. The blossoms all fell off though. The plants lived and kept growing, but we didn't have hardly any blossoms set after that. Maybe it was the weather.