Some kinds get it even if you're doing everything "right." What kind are cracking?

Yes it can be from over-watering. That's the most common cause. The water causes the inside of the fruit to swell and the skin cracks. And yes, it is still possible to over-water even with a drip system. ;)

But as Jean said, some varieties are very prone to cracking no matter what.

Dave

I wish I knew how to avoid/minimize cracking myself. In one raised bed, right next to one another, are an Aker's West Virginia and an Indian Stripe. The Aker's are smooth and perfect and the Indian Stripe are cracked to hell. Must be genetic.

I had cracking on my Amish Paste and Box Car Willie last year. We had
a lot of rain. The tomatoes were very big on both plants. You said your
soil is always moist. Tomatoes do not need a lot of water. The soil
should not always be moist. You might wash out some flavor. 1 inch
of water per week is suppose to be sufficient. If you live in an area that
does not get much rain, mulch the tomatoes with straw or grass clipping,
hardwood mulch, newspaper,,etc...

"The Aker's are smooth and perfect and the Indian Stripe are cracked to hell. Must be genetic."

I disagree. Indian Stripe have been consistently easy to grow without either concentric or radial cracks for me every year since 2006.

Here's a few from last year that show typical results.

Fact is, those were grown in a black nursery tub, neglected somewhat, and watered every other day or so right out of the end of a garden hose with a 20-count stream of water that flooded the growing mix. So I don't get it that Indian Stripe is genetically predisposed to cracking, because it's not, in my experience.

Hoosier just referred to radial and concentric splitting so I thought I'd just kind of list them below.

Radial splitting is seen as splits that come out from the stem end, as in radiating outwards, and they are perfectly normal for many tomato varieties b'c in part it's genetic. They usually scar over. But with too much rain or too much irrigation they can split open again and normal bacteria and fungi in the air can invade and initiate a rotting process.

Concentric splitting is seen as circular splits around the stem end and they too are perfectly normal for many varieties and they too usually scar over and then do as I said above in terms of splitting open again.

So with the above two kinds of splitting it's a genetic situation and the initial splits are not caused by too much water, etc.

Horizontal splitting is seen as splits on other areas of the fruits and these are usually due to too much water getting into the fruits from too much rain or irrigation. That water doesn't cause the fruits to swell, rather, the fruits split b'c the epidermis at maturity or close to it can't expand and so the epidermis splits.

And no, fruits don't blow up. I've seen folks who have said my fruits blew up b'c they got too hot and just plain burst. Nope, doesn't happen. It's too much water and the inability of the epidermis to expand beyond its mature structure.

Hope that helps.

Carolyn, who can ID some varieties just by the pattern of the concentric splitting; one good example is Black from Tula which has a single circular scar line that ends in an open unclosed line.

I grew 12 varieties this year. Indian Stripe(aka Indian Crack), Berkley Tye Die, Cherokee Purple, and Cherokee Green were my worst crackers.

Each Indian stripe had a crack from the top to the bottom that exposed the seeds. An Berkley was the only tomato that cracked from the bottom.

The tomatoes that didnt crack at all were KBX, Rose, and Green Zebra(as well as Black Cherry and Isis Candy).
Brandywine Sudduth, Black Brandywine, and Black from Tula had very little cracking.

For what it's worth, I can ggrow variety X one year with no splits and grow the same variety a different year and it splits and I'm talking about the horizontal splitting I talked about above b'c the other kinds of splits are pretty much genetically determined.

Each season is different with regard to environmental variables so that's why I think it's difficult to say this or that one is a splitter unless grown in different seasons. Just my opinion.

Sorry to hear about your Indian Stripe b'c I've grown it quite a few times and have never seen any kind of splitting whether that be radial, concentric or horizontal.

Maybe I'm just lucky although I think I remember Hoosier saying the same thing in a post above.

Carolyn

Carolyn, I understand what you are saying, I've followed you and Hoosier for the past few years on multiple sites.

That was just my experience this year with my environmental factors. I got the IS seeds from the exchange here, so who knows. My BFT also cracked differently as well, it looked like a bunch little cracks around the stem, and those are from SSE.

The OP is in my zone, and we share the same problems, so just wanted to my .02

Maybe the Indian Stripe just isn't enjoying the Southern AZ climate this year. It and the Aker's WV are no more than three feet apart in a raised bed on the same drip system. I'm glad to hear that it isn't genetically predisposed to cracking because the flavor is exquisite and I'd like to try them again next year. Aker's will definitely be back next year.

I've had horrible cracking on my C. Purps and German Pink this year. My solution has been to pick them as soon as they start to blush and ripen them on a rack(stem side down, yo).