I have heirloom and hybrid tomato plants this season. Now I realize the season is still early but the hybrids seem to be out producing the heirlooms at least three to one and in some cases more than that. This is counting both green tomatoes as well as blossoms on the plants. Unless the heirlooms come on like gang busters later in the season, the hybrids will win hands down as far as production.
Rich from PA Zone 5-6