How Long Does a Tomato Stay on the Vine Before Turning Red?

General Time Frame

• Standard size tomatoes need 40 to 50 days to reach the mature green stage. At this point, the tomato is as large as it is going to get. Once it reaches this stage, it will begin to ripen, a process that may take 15 to 30 days or longer. Tomatoes ripen gradually, turning from bright green to pale green, pink and finally red.

Varieties

• Tomato ripening times vary depending on the variety. Several short-season types, such as "Sub-Arctic Plenty" and "Cherry Gold" mature in 45 days or less. Quick-ripening tomatoes are usually small cherry or grape tomatoes. Large beefsteak varieties, such as "Beef Master" and "Supersteak" may grow for 70 days or longer before ripening.

Weather Conditions

• The ideal conditions for ripening tomatoes are warm, dry days with temperatures between 68 and 77 degrees Fahrenheit. When temperatures deviate much from that range, ripening may slow or halt. When temperatures rise above 85 degrees Fahrenheit, the plants stop producing lycopene and carotene, the compounds responsible for a tomato's bright color. Under these conditions, tomatoes will stall at the mature green stage until more optimal weather returns.

Tips for Ripening Tomatoes

• To accelerate ripening, remove any young, hard green tomatoes that appear 8 weeks before the first expected frost. These tomatoes won't ripen before frost arrives, and slow down the ripening process for the more mature tomatoes already on the vine. Pinch off any new vigorous shoots as well; this diverts the plant's energy into ripening fruit rather than wasting it on producing unneeded foliage.