Both problems are generally caused by uneven watering. Are they in pots or in the ground, Backforthe2ndtime?

1) Sounds like blossom end rot. This is caused by a mineral deficiency in the soil. The cellular walls in the tomato aren't getting sufficient calcium or magnesium & collapse & rot on the vine. This could also be cause by insufficient watering. Find a high quality tomato feed and work it into the soil around your plant. I recommend JOBE’S ORGANICS VEGETABLE & TOMATO GRANULAR. I'm using this and my tomatoes look perfect. You can also add a couple tablespoons of epsom salt to a gallon of water and use it as a foliar spray.

2) Is cause by too much water. This usually happen following a rain storm or if you deluge your tomato plants with too much water. This causes the tomato to swell & crack.

Plant your tomatoes very deeply, up to the top 2 leaves. The roots will go down deep & find it's own water. Don't flood your tomatoes. Keep the soil barely moist. Water maybe once per week.

As already suggested, its simply your watering causing the issue, both the problems you describe are physiological disorders. Irregular and/or insufficient water is the primary cause. Blossom end rot because irregular or insufficient water disables calcium take up, and fruit split because the plants have not been sufficiently well watered for a while, then suddenly they get a lot of water all at once and the fruits swell too quickly, the skin can't keep up, and it splits.

If they're in pots, water well, regularly, (daily at least if they're in hot sun) allow the pots to drain down freely, don't leave them standing in water in any outer tray. If in the ground, its a bit harder to keep them efficiently watered, but they'd need a good soak every day during hot and dry spells.

In the ground, think someone tossed tomato seeds in my compost, cause that's where their growing. Right in front of my compost. I have crushed egg shells and sprinkled that around the plants, not enough? How do I control the water if they are in the ground? We had a severe storm yesterday, rained for an hr straight. Rained hard. Seems to only happen when they are ripening.

The blossom end rot and the cracking. Only seems to happen when they ripen.

No, blossom end rot isn't merely caused by insufficient watering though that may be a contributing factor. It's due to certain minerals lacking in the soil which the tomato plant needs for proper development. Tomatoes are extremely heavy feeders and is a mineral dense fruit. Blossom end rot is caused by a calcium deficiency. Obviously water is necessary to move the calcium. You must also feed your tomatoes for proper development. As I mentioned above, Jobes is an excellent tomato feed which will prevent blossom end rot. That's what I'm using on my tomatoes and it works.

Here is a picture of my tomatoes http://www.growsonyou.com/photo/slideshow/331997-cherokee-purple-tomatoes/member/bathgate

The above advice is incorrect and will guarantee blossom end rot and fruit split. Planting deeply in the ground is best for tomatoes. The ground is evenly moist deep down and will provide and optimal growing environment. The above advice will cause mineral leaching, fruit split & mineral deficiency. Don't soak your tomatoes everyday. That will cause fruit split & blossom end rot - leaching the calcium & minerals out of reach. Your soil PH is another factor to keep in check.

Here is an article which offers more detail.

https://bonnieplants.com/library/conquer-blossom-end-rot/

"If you see a dark, rotting spot on the bottom of your tomatoes, it’s blossom-end rot. This problem, caused by a calcium deficiency, can be solved a few ways."

Have a look at this link - you'll have to copy and paste into your browser. It contains secondary links to both blossom end rot and fruit cracking/splitting

https://www.rhs.org.uk/advice/profile?PID=392

You obviously can't control how much rain falls out of the sky - but you can water the tomatoes well on a daily basis if its hot and dry, or even just dry, giving each plant a gallon or two, watered round the base of the plants. If the plants had sufficient water when there wasn't much rain around, they wouldn't have accelerated the fruit's growth so much that the skins couldn't keep up when there was plentiful rain and water, and they would have been able to take up calcium with the water to prevent blossom end rot.

If you've had blossom end rot as a problem year on year, you might want to get your soil's levels of calcium checked, because that makes it more likely there's low calcium content, but because you've got skin splitting AND blossom end rot, that points to a water supply problem rather than actual calcium depletion in the soil.

Blossom End Rot & Fruit Splitting are two separate unrelated issues. You can have either or both.

I have either & both. Some have one, some have both, some have neither. My neighbor picked one that was perfect. While I have one that I picked that was cracked. Meanwhile, all of hers are in pots, and all hers are perfect. An numerous.

Thank you Bath & Bamboo.