How to Prune Tomato Plants #Organic_Gardening
The best time to prune suckers off of your plant is when they are young like in the picture above. At this stage of growth you can simply snap off the sucker with your thumb and index finger. If the sucker is as thick as a pencil a sharp knife or hand-held pruners should be used. Sterilize the knife or shears after ever cut to lessen the chances of spreading a disease that will kill your tomato plant.
If you didn’t notice the sucker until it grew to a size thicker than a pencil, I would recommend just leaving it alone and allowing it to flower and fruit. I’ve damaged and killed many a tomato plant by trying to remove a sucker that was just too thick. It is better to be safe than sorry.