Nutrients. Low N, high P feeding back about early Sept. would have helped. Try one now.

Dave

Thanks. I'm a little reluctant to add P because our native soils (alkaline, on top of limestone) have quite a lot. I haven't done a soil test in a number of years, but when I did the P came out pretty high, and I just keep adding compost, which is only going to make it higher.

I will certainly not add N, as I don't need more green.

In fact, looking closely, I'm starting to see some really tiny flower buds. It'll be several weeks before they open. I'm just a little surprised that the plants just quit flowering entirely during the worst of the heat. I always thought they would continue flowering, but the fruit just wouldn't set. Guess not. The plants must be smart enough to figure that if the fruit isn't going to set, why waste energy making flowers.

The timing on nutrient availability can be crucial. Especially for maintaining blooming ability. But as long as you have an active soil micro herd to convert the compost to nutrients it should be sufficient.

But the big IF is soil pH. If your soil pH is out of substantially out of whack then you can have all the nutrients in the world in the soil but the plants can't use them. Again a steady diet of compost should prevent that assuming sufficient bacterial activity to work on it.

Dave

Thanks. Good advice. There has been plenty of applied compost and dug-in mulch over the years, so I think I'm OK. Also, as noted, these tomatoes at this location produce strongly in the spring. I've just never tried going for fall production.

I'm in SoCal and have heard about late crops in my
area too. I've tried a few times, but never have gotten
anything worth the effort to keep the plants going.

I do manage to keep them going through late Sep, but
it's fruit that set earlier in the year, not new fruit set.