Practical experience tips:

1) use much bigger containers. 5 gal. is the very minimum and very problematic. Especially important when growing indeterminate varieties.

2) use a good quality soil-less potting mix to fill the containers.

3) do NOT count on the nutrients supposedly contained in the mix. With containers the nutrients leach out every time you water so they must be replaced regularly. Use your fertilizer of choice and feed the plants weekly with a 1/2 strength mixture.

4) leaf curls (actually named 'tomato leaf roll') is a sign of stressed plants and is usually related to inconsistent soil moisture levels. Stabilizing the soil moisture level will eliminate the problem.

Hope this helps.

Dave

PS: check out the California Gardening forum here for contact with local and regional gardeners.

I'm a little south of you in Merced.

Are your plants protected from the wind? With your Delta winds, with a container that small, my guess could be that your watering is inconsistent and maybe drying out with the winds.

I grow organically and only use a half handful of Dr. Earth's or other good organic vegetable fertilizer in the planting hole when transplanting. However, I also grow in the ground, so I can't compare to someone growing in containers. You may have indeed burnt them when applying your last fertilizer. Good rule of thumb, especially with containers, is to cut the label amount by half or even 1/4 to prevent overfertilizing.

Elaine

Are your containers mulched well? With small containers, a hot climate, and potential winds, mulch is essential!

Depending on your container, it is possible your problems are from the roots cooking in plstic pots. In our climate it is best to make sure pots themselves are shaded from the sun, either by other plants growing up around them or by wrapping something like insulation around the pot. Although I might add that Green Zebra and Yellow Pear are both among my LEAST favorite tomato varieties, so if you were going to lose some plants, those are the ones to lose!!!
Carla in Sac

I live in Lodi and have 2 heirloom cherry, and 1 heirloom green grape, tomato plants in 16" containers, which are probably closer to 10 gallons. The plants are large and thriving with lots of fruit, but the tomatoes are super tiny. I haven't fertilized regularly, but will do so going forward (thanks digdirt). I soak each planter pretty well about twice a week. Mine are not mulched, but thanks to the tip from missingtheobvious (apropos), I will be doing that tomorrow. One good thing about these plants, the tomatoes on all 3 are the most delicious I have ever tasted, including my 7 other in-ground varieties.
I used Hollandutch Nursery's proprietary potting soil (organic and pretty potent at full strength).

I live in Modesto and I tried tomatoes, squash, lemon cucumber, Serrano and bannana peppers in 5 gal buckets last year and all did poorly except for the peppers. Like you said they took off great at first but 5 gallons is just not enough for most tomatoes and squash. I double dug a garden in my backyard in August, planted carrots, radishes and several kinds of lettuce and it produced like crazy. I also added a raised bed this year and that is doing great. I guess the moral of the story is containers work well for some veggies but squash, tomatoes(not labelled container friendly) and cucs need more space than 5 gallons. Some people may get results with those plants in 5 gallon buckets but planting in the dirt has made a world of difference for me.

I think veggie container gardening in the Central Valley is a challenge in the summer, too. You can grow some nice winter greens in containers here without too much difficulty.

That said, I potted up 3 peppers in a large container (with marigolds) today. I will place it among a cluster of pots with (tough) flowering plants to shade the pot with the peppers in it. Don't think I'll be experimenting with containers for tomatoes soon, though.

I am also in the Central Valley (Modesto). I have a gardening page dedicated to container gardening on FB. Feel free to check it out.

Here is a link that might be useful: Growing Vegetables in Containers