How long can you leave a ripe tomato on the vine?
Also, how do you know when tomatoes are ready to pick?
Gently squeeze your tomatoes to test for firmness. A ripe tomato will be slightly firm. If it's too hard, it probably needs more time to ripen. If it's too soft, it's probably over-ripe and should be picked and thrown away.
In this regard, do tomatoes ripen faster on or off the vine?
This is possible because tomatoes continue to ripen even when removed from the vine — thanks to ethylene, a naturally occurring plant hormone that many foods, including tomatoes, release. The more ethylene tomatoes are exposed to, the faster they ripen.
Harvest time for tomatoes should ideally occur when the fruit is a mature green and then allowed to ripen off the vine. This prevents splitting or bruising and allows for a measure of control over the ripening process.