It was 46 F. this morning in Rye, and while I’m happy to have the cooler temperatures, tomato plants don’t see it the same way. Tomatoes are a bit fussy–they don’t like temperatures below 50 degrees, and they won’t set fruit if the temperatures get above 90 degrees. Really, they’re happiest in the 70-80 degree range. And who isn’t?
Did you know that it takes about 42 days from the time a tomato flower opens until the fruit is ripe? That’s just an average, cherry tomatoes take less time to ripen, but cooler temperatures can make any type of tomato take longer. With that timeframe in mind, and knowing that the first fall frost is around October 1 (for Rye, Colorado Springs, La Veta, Beulah, etc.) or October 8 (for Pueblo and other towns on the plains) then you know that letting your tomato plant flower after today isn’t really helpful. You don’t want the tomato to set fruit that has no chance to ripen. You can’t really stop your tomato plants from flowering, but you can cut them back at the top. Pruning any branches that don’t have fruit on them now will help your tomato plant put all of its energy into growing bigger fruit and ripening it before frost. Cut off all flowering tips back to where you see green fruit. It seems scary, but it makes sense.
This is also a time of year to be ready to cover tomato plants as the night-time temperatures drop. The dates I mentioned above are “average” frost dates, that means some years frost comes earlier. Often an early frost is followed by weeks of warm temperatures–Indian Summer–so don’t let an early frost take out your tomato plants before you’re ready. Some people use cotton sheets draped over their tomato cages with good results. I have a fabric called Remay that I use–that’s a trade name for a spun polyester material that is very light weight. Cardboard boxes work, too, if you have any large enough.
If you realize you can’t protect all of your tomato plants, pick the best and biggest green tomatoes, or half-ripe tomatoes and continue to ripen them inside. I’ve mentioned the blog A Garden for the House before, and Kevin has a great article about ripening tomatoes inside: http://www.agardenforthehouse.com/2012/08/how-i-ripen-tomatoes-indoors/
I hope you all have had a good tomato summer, despite the heat and extreme drought.
