Hmm... The part that I'm a bit confused about is watermelons are abundant now but I wouldn't be planting new tomato plants in the ground at this point. Maybe experimentation is possible further south where there is a full fall growing season for tomatoes?
When I would be planting tomatoes in beginning of May, watermelon would be rare/expensive and likely imported from S. America -- not worth buying.
But My garden is still getting raided occasionally by some non-resident goundHOG so I would also be concerned about attracting vermin.