I would suspect the pots in full western exposure. The roots get so hot they give out.

Can you get them some shade or plant in the dirt?

Whose book did you read?

http://www.tucsongardener.com/Year98/marapr98/vegetabl.htm

Pots are a bummer here, they heat up so quick for veggies.

That afternoon sun is also killer.

We water our potted veggies twice daily and they still look way worse than our in ground (raised bed) veggies.

Spacing of seedlings could be an issue.

Soil mix could be an issue.

The actual "color" and material of you pots could also be an issue.

Current books in our library that we read often are:

Desert Gardening for Beginners - Cathy Cromell, Linda A. Guy, Lucy K. Bradley

Gardening in the Deserts of Arizona - Mary Irish

Extreme Gardening, How to Grow Organic in the Hostile Deserts - Dave Owens, "The Garden Guy"

All New Square Foot Gardening - Mel Bartholomew

Arizona Master Gardener Manual - UofA College of Agriculture and Life Sciences (had the daughter pick this up for us, she's a med student at UofA)

The books in my library include:
- Gardening for Beginners: How to Grow Vegetables in Arid Climate by Cromell, AZ Master Gardner Press
- Desert Harvest, A Guide to Vege Gardening in Arid Lands by Nyhuis
- Desert Gardening Fruits & Veges by Brookbank
- Gardening in the Deserts of Arizona - Mary Irish
I have more, but you get the picture.

Thanks for explaining, that the "pots get hot and that kills the roots." Frankly, that never would have occurred to me, that roots in the ground stay cool, while those in the pot get much hotter. I have moved the pots so they get a bit less sunlight.

Since I can't (yet) get the plants into the ground, my plan is to wrap the pots with reflective material (cheap space blankets) that will reflect the heat away from the pots and thus keep the roots cooler.

All other suggestions and ideas are welcome. Thanks!!

tucsonmax,

Glad to see the desert gardening books in your library. Most folks move here and think it's the same as back east or middle America. Not even close. Our climate is unique and 3 clicks from the sun :)

What type of "pots" are the veggies in? What color?

You could also double up the pots, stick them in larger pots with an insulating layer of sand in between the pots. Think: making ice in the desert ...

Here is a link that might be useful: Making Ice in the Desert

mangledmind: I bought carmel color plastic (fake-terra-cotta) pots from Home Depot. Since I have 18, I'd rather not buy another 18 larger ones... but that's a great idea. Maybe I'll buy smaller ones, use the ones I have as the outside ones?

I have set aside and put in PVC on a 250 sq ft plot that I will eventually build 4 raised beds... but that's not until next year. My goal this year was to simply experiment and learn.

tucsonmax,

Try to cut the watering down to just the morning, with a good heavy soak. If you notice the following morning that the plants are still up-right and look good then a light watering.

Are you able to provide afternoon shade for your pots?

Will cut-down the watering and see what happens.
Unfortunately, "No" on providing afternoon shade. But I did move them to where they sun doesn't reach them for 2-3 hours later in the AM.

Shoot, Tusconmax, you set about everything the right way, but nobody I've read talks about roots cooking in pots during our summers. Anything at all you can use to shade those pots would be very helpful: cardboard boxes, styrofoam panels that are used for house insulation, bales of straw, concrete blocks....really anything that will keep the sun from striking the pots. I won't be beautiful but it will save your plants.

Since it's been a while, I thought I'd post my results.

I pulled-out everything, turned the soil, moved all of the pots to a southern exposure that's a tight fit in between my house and brick wall, meaning they get partial sun most of the day, but significantly less then before. Plus, I wrapped the pots in sun screen fabric. I planted almost everything from seed again and the difference is incredible. The cantaloupe vines are 6 feet long, the squash has taken-off, the peppers are doing well and everything else is substantially better. And best of all, my kids are having a ball watching and helping! Thank you all for your advice!

:) good to see the update ... glad they're doing better