What makes tomatoes grow sweet?

Pretty basic question but I really don't know the answer.
Two gardens ago, we grew cherry tomatoes that came up sweet as candy. Amazing.
This year they're coming up in abundance, with decent overall flavor, but fairly acidic and not at all sweet.
I'm wondering what variables make the difference, if anyone knows.
It's a small, and probably overcrowded, little patch behind our house. Decent but not overwhelming amount of sun. The toms are near eggplant, cucumbers, peppers, arugula, and the usual herb suspects. All are doing well except the little strawberry plant, which is being mercilessly harassed by pests.
They're all growing in organic dirt from Home Depot.
Tips for next year?

This year they're coming up in abundance, with decent overall flavor, but fairly acidic and not at all sweet.

I am inferring that these were volunteers, not plants you put in this spring; what variety were the plants you put in two years ago? If they were a hybrid variety, it sounds like the volunteers have reverted to type. If they are from new plants (or if you grew the starts from seed), try a different variety next year.

Though I haven't noticed this with tomatoes, I'm noticing that most other local sweet crops aren't as good this year due to the huge amount of rain (at least, that's what the farmer told me about his peaches.) It certainly is a variable in this year's produce.

The type of tomato planted would of course be the biggest variable, and depending on where you got the plants, you might or might not be able to trust the label on them (ie, Home Depot vs. Gethsemene Gardens). And after that, whether you picked them at le moment juste -- I believe the sweetness peaks as they ripen.

That said, I think our tomatoes are kind of watery tasting this year, due to all the rain.

Judy H wrote:The type of tomato planted would of course be the biggest variable, and depending on where you got the plants, you might or might not be able to trust the label on them (ie, Home Depot vs. Gethsemene Gardens). And after that, whether you picked them at le moment juste -- I believe the sweetness peaks as they ripen.

That said, I think our tomatoes are kind of watery tasting this year, due to all the rain.

As far as trusting Gethsemene's labeling: last spring we were asking for tomatillos. A worker pointed us to an unmarked plant, we took her at her word (though the appearance was odd).
Now we've got a nice batch of Thai Yard Long Beans!

Wow, that's not good. We've generally found the staff there reasonably knowledgeable, but they have gotten so big it sounds like they are losing control. We like Anton's in Evanston. Unless the staff is really on top of things, it is so easy for a customer to pick up a plant one place and put it down another place, pull out a tag and drop it.

No excuse for a worker to mix up beans and tomatillos, however.

bean wrote:

Judy H wrote:The type of tomato planted would of course be the biggest variable, and depending on where you got the plants, you might or might not be able to trust the label on them (ie, Home Depot vs. Gethsemene Gardens). And after that, whether you picked them at le moment juste -- I believe the sweetness peaks as they ripen.

That said, I think our tomatoes are kind of watery tasting this year, due to all the rain.

As far as trusting Gethsemene's labeling: last spring we were asking for tomatillos. A worker pointed us to an unmarked plant, we took her at her word (though the appearance was odd).
Now we've got a nice batch of Thai Yard Long Beans!

Sounds like it wasn't matter of trusting the labels, but trusting the employee. Unlike the labels, the employees are very smart but fallible.

Our tomatoes are beginning to ripen-a lot of green ones are still out there. It seems that as soon as they develop that rosy/yellowish blush as the ripining begins small gnat like bugs start to bore holes. By the time we pick them for final reddening the bugs have ruined the fruit. They start to fly around my windowsill after a few days. We have a totally organic garden and any recs as to a safe way to repel these bugs would be most appreciated. .

I don't have an answer for you, but I have always had good luck with the Ask A Hort service of the Illinois Extension office: http://web.extension.illinois.edu/askex ... kSiteID=34

One garden website suggested using a keyboard vacuum to capture the bugs (and subsequent dumping of the contents into a bucket of soapy water) is a good solution.