Why Aren't My Tomatoes Ripening?
Steve Reiners, Co-Team Leader, Cornell University
Eastern New York Commercial Horticulture

So what's happening? It takes six to eight weeks from the time of pollination until tomato fruit reach full maturity. The length of time depends on the variety grown and of course, the weather conditions. The optimum temperature for ripening tomatoes is 70 to 75F. When temperatures exceed 85 to 90 F, the ripening process slows significantly or even stops. At these temperatures, lycopene and carotene, pigments responsible for giving the fruit their typical orange to red appearance cannot be produced. As a result, the fruit can stay in a mature green phase for quite some time.
Light conditions have very little to do with ripening. Tomatoes do not require light to ripen and in fact, fruit exposed to direct sunlight will heat to levels that inhibit pigment synthesis. Direct sun can also lead to sunscald of fruit. Do not remove leaves in an effort to ripen fruit. Also, soil fertility doesn't play much of a role. We do know that high levels of magnesium and low levels of potassium can lead to conditions like blotchy or uneven ripening or yellow shoulder disorder. But the slowness to ripen is not likely due to soil conditions and adding additional fertilizer will do nothing to quicken ripening.
If you absolutely cannot wait, some growers will remove fruit that are showing the first color changes. These fruit, in the a mature green or later phase, could be stored at room temperature (70-75F) in the dark. A more enclosed environment would be best as ethylene gas, released from fruit as they ripen, will stimulate other fruit to ripen. If temperatures remain high outdoors, these picked fruit will ripen more quickly, perhaps by as much as five days. As far as flavor, the greener fruit should develop flavor and color similar to what you would get if field ripened. The key is picking them when they are showing the first signs of ripening (no earlier) and keeping them at room temperature. Do not refrigerate, as this will absolutely destroy their flavor.


Upcoming Events
Chautauqua Winter Vegetable Meeting

February 10, 2023
Clymer, NY
Meeting will feature growers from Ohio sharing their production know-how and thoughts on food safety. Other topics include weed control, pesticide safety, and the impact of poor crop nutrition. 0.75 DEC credits in 1a, 23 plus 0.5 in CORE, which is good for all categories. Trade show booths available.
Meeting cost is $20/person, includes snacks and educational materials. Registration required by 4 pm on Friday, February 3.
Orleans Regional Vegetable Meeting

February 15, 2023
Albion, NY
Offering presentations in pesticide safety, tips for managing diseases in vegetable crops, how to attract beneficial insects to your field, herbicide options for cole crops, and strawberry disease information. Meeting cost is $10 per person, payable at the door via cash or check. Pre-registration requested by 5:00 pm on Monday, February 13.
DEC credits available: 2.25 in 1a and 10; 2.0 in 23; 1.5 in 22; and 0.5 in CORE (used in all categories)!!
NYS Processing Vegetable Industry Roundtable Meeting

March 15, 2023 : Morning Session: Snap Beans, Sweet Corn, and Peas
Batavia, NY
Processing vegetable industry members who grow, manage, or support snap bean, sweet corn, or pea production for Nortera and/or Seneca Foods, should attend this session of the roundtable meeting. You will:
- Network at this in-person meeting.
- Learn the results of industry-funded research.
- Have a voice in Cornell research and extension.
- Earn 2.0 DEC credits in categories 1a, 10, 23 and CCA recertification credits.
This FREE event is followed by lunch! Pre-registration requested.
March 15, 2023 : Lunch Break and Networking
Lunch is FREE to anyone attending either the Morning Session or the Afternoon Session of the NYS Processing Vegetable Industry Roundtable Meeting. Registration is required.

March 15, 2023 : Afternoon Session: Beets and Carrots
Batavia, NY
Processing vegetable industry members who grow, manage, or support beet or carrot production for Nortera, Seneca Foods and/or Love Beets, should attend this session of the roundtable meeting. You will:
- Network at this in-person meeting.
- Learn the results of industry-funded research.
- Have a voice in Cornell research and extension.
- Earn 2.0 DEC credits in categories 1a, 10, 23 and CCA recertification credits.
Lunch is provided before this session. It's FREE! Pre-registration requested.