What can cause tomatoes to stop ripening?

June 21, 2019 10:21 AM

Last year, our tomatoes did wonderfully - until the end of summer, when they just stopped ripening. We had beautiful, healthy plants full of green tomatoes that stayed green. More details inside.

Y'all were great with my last plant question so I figure I will start a new one. I did Google this and found some pages like this one, but it doesn't quite fit:

https://commonsensehome.com/tomatoes-not-ripening/

Last year, we cleared a patch by the side of our rental house for a garden, and planted some tomatoes, hot peppers, and zucchini. Everything did great - wonderful, bushy plants, and the tomatoes were gorgeous. We live in lower Michigan. I grew up in Missouri and my family always grew tomatoes there, but the climate is on average about 10F hotter there.

I had several varieties, some with shorter maturation times than others. They all did ripen at first and were delicious. But then toward the last part of summer, they just ... stopped. The fruit stayed green. It looked very healthy otherwise! No signs of rot, etc.

I don't think it was that the weather got colder - they stopped ripening well before the temperature changed much. It also wasn't too hot. My roommate wonders if it was the soil, but I'm not finding much about that online - and the plants did so well otherwise. We did fertilize now and then. I'm left wondering if it had something to do with not getting enough light. The only place we can plant them is next to the house, which is fully sunny until late afternoon, when it gets blocked off by shadow (and earlier, after the solstice).

So, what do you think? If there's anything I can do differently I'll try it. This year's tomatoes are already in the ground and looking great, like last year. I can do things with green tomatoes but nothing beats a good ripe homegrown tomato and I WANT TO EAT AS MANY AS POSSIBLE.

posted by Kutsuwamushi to Home & Garden (5 answers total)

It will probably be due to lower temperatures as the growing season winds down. You might want to experiment with partially enclosing your plants with plastic film over a frame to make a little ad hoc greenhouse once their ripening rate starts to slow down.

Once you do hit the ripening wall, this advisory video is pretty sound.
posted by flabdablet at 10:38 AM on June 21, 2019 [2 favorites]

I had a lot of still-green tomatoes at the end of last growing season (zone 7). When a big storm was forecast that was likely to blow them all down, I just picked them all and put them indoors in a bowl. It took a long time - a couple more weeks, maybe - but they all ripened up indoors.
posted by xo at 3:07 PM on June 21, 2019

Overnight temps cooling off is probably the issue. You can pick green ones and wrap in newspaper indoors to encourage ripening. OR! You can do what I do and fry those green tomatoes after dredging them in buttermilk>flour>cornmeal with a pinch of cayenne.
posted by little mouth at 4:05 PM on June 21, 2019 [1 favorite]

You may be on to something with the amount of sunlight; what was an acceptable amount of sunlight in late June may not be adequate several weeks later. If this year's crop doesn't pan out, I'd experiment with planting the tomatoes in big pots and moving them around as the season goes on to catch the most sunlight. Bonus is that you can move them inside if you get an unseasonable freeze.
posted by Tuba Toothpaste at 7:40 PM on June 23, 2019

Did you remove the leaves to encourage the last ones to ripen? That would be what I would try before picking them to ripen indoors. Pinch out the top nice and early so the plant's not putting its energy into growing taller and making more flowers, and then just start removing the leaves from the bottom once all the tomatoes are there and ripening has slowed.
posted by london explorer girl at 3:02 AM on June 24, 2019