It seems that only yesterday I was picking my first ripe tomato of the season. Now I’m looking at the vigorous vines still full of green fruit and wondering… how long will the warm weather last this year? Is there will time for these to ripen? If not, when should I pick them? How should I store them? Is it OK if they freeze?
It’s early October, with warm, golden days and crisp nights, and frost could come at any time. In fact, October 10 is the average first frost date in Colorado Springs. (Where I am, 1,000 feet higher in elevation than downtown, I have to subtract 10 days (one day per hundred feet), which means that in any given year, my garden has a 50% chance of seeing a frost by October 1.)
It’s helpful to know my average frost date, but I still need to keep an eye on the weather reports. If frost threatens, but the weather is generally warm, I just throw a blanket over a plant for a night or two. Keep it from freezing, and I continue to get nice, vine-ripened tomatoes.
However, when dealing with tomatoes, the average temperature is much more important than the first frost of fall. When the nights are consistently cold, and average temperatures over a 24 hour period routinely fall below 60°, keeping the plants from freezing won’t prolong the harvest. The tomatoes might continue to ripen, but odds are we won’t want to eat them.
Tomatoes exposed to prolonged chill become watery and lose their homegrown goodness. Even storing them in the fridge will rob you of the flavor we crave. This is because that wonderful tomato aroma and taste come from a chemical, Z-3 hexenel, that the plant can only synthesize at temperatures above 55° or so.
If I want to avoid tasteless, mealy fruit, I store them at room temperature, or better yet, eat them still warm from the garden!
When temperatures are consistently cool, I finally acknowledge that tomato season is over. Before the last stragglers are ruined, go ahead and pick what is left on the vine.
Then, if I’m 100% certain my plants are disease-free, I pull them out and shred them into the compost pile. Otherwise, I dispose of them in the trash. Early blight, the most common tomato disease along the Front Range, overwinters as spores on plant debris in the soil. Composting doesn’t destroy it, and I sure don’t want to risk re-infecting next year’s plants.
So… will those green tomatoes become juicy red fruit?
I’ve found that if a tomato has started to change color from green, even if it’s only yellow, it will continue to ripen in the house. Of course, nothing that ripens on a counter can compete with fruit that ripens right on the vine. Still, it’s not any worse than supermarket produce. I just leave them sitting along the back of the counter—a nice neat row from greenish to ripe, reminding me of the summer just past. Some people wrap the tomatoes in newspaper to keep one rotting fruit from contaminating the rest of the pile. I’ve never found that to be necessary.
For tomatoes that are truly green when picked, well, we’ve all heard of fried green tomatoes.