From your posted descriptions, in this and other posts, of your soil it sounds like the soil is the problem, not the tomato variety. ;) Constructing raised beds would solve most, if not all, your problems.

But no, AFAIK, there are no tomato varieties - or any other plant for that matter - that will thrive under the conditions you describe. They may grow and even produce some, but not thrive.

Dave

californian

Why don't you look into gardening in raised beds? I have red Georgia clay, which is great for growing some things, but without rain for a while, it looks like Death Valley, all cracked and hard.

So I use raised beds for most of my garden vegetables. You just need to find plenty of compost or compostable materials to fill the frames with. I'd build them so they're 8-12 inches deep.

You'll find that the composted contents of the raised beds will gradually "soften" the clay soil under them and improve your clay so that roots can penetrate even more deeply. FWIW, many clay soils are rich in plant nutrients if the plants can get to them.

Furthermore, if you dig holes in clay soil and add compost or peat moss to the hole, your tomato plants are not likely to thrive -- that creates a "bowl" that holds water when it does rain. It doesn't drain well.

Do some research on raised garden beds.

Another help for your problem would be to install drip irrigation. It isn't that expensive if you do it yourself and it is easy to add to. I have a hill of clay soil for a backyard and the drip irrigation was the only way to water without it all running down the hill. With drip the water comes out slowly over a long period of time so it can sink in. Check out the dripworks website - that's where I got my system from.

I would terrace the slope using retaining wall block available form Home Depot and Lowes. Home Depot carries Verdura 30 which is the one I like.

Fill behind the block with good imported topsoil to give yourself a raised bed on a slope.

Be careful when buying topsoil. Most stuff labeled as topsoil isn't really topsoil.

Zeuspaul

Ditto the raised beds and steady watering. Sounds like your seedlings might have been a bit potbound and then encountered a pH problem. 6.5 is best when you can get it there and keep it there. I agree you should use some of your native soil heavily amended with compost and any other ammendments necessary to correct any deficiencies as indicated by a soil test. Long, narrow, terraced beds with good soil and drip irrigation might work for you. Will certainly produce great tomatoes.

I don't want to terrace my yard because I will no longer be able to use my rototiller if I do. I already built five retaining walls, and don't want to build any more. Too much water is almost never a problem in southern California, not enough rain and water rationing is the problem. I do build berms out of clay and compost, but I can rototill them flat after the first rain of winter, and rebuild them in the spring.

Well nothing says you can rototill raised beds. I do all of mine each spring - even the one on the steep incline. You just have to till across the bed or take care to not let the tiller get away from you when going down hill. ;) And nothing says raised beds have to be terraced either. They can run in any direction if necessary - even on an incline.

But what they do accomplish for you is the ability to improve your soil, your growing medium and that appears to be your primary problem. With raised beds filled with a good growing mix your problematic clay soil then becomes irrelevant.

As Anney said above, many have to contend with clay soil, many of us have to contend with glacier scrub and bedrock, and many have steep inclines to deal with as well. But thousands of gardeners have discovered that building contained raised beds eliminates all those problems. Simply leave one end open - 1/2 a railroad tie you can drag out of the way works fine - for tiller entry.

Dave

I garden on a slope in Southern California. I water with soaker hoses to save water. I had trouble with runoff from the soaker hose. I terraced the garden and the problem went away. I didn't use block, just cut into the slope. I roto till without a problem. It's easier to rototill the terraces than it was the slope.

Zeuspaul