Your little dark spot is called blossom end rot, and is usually caused by too much water. Slack off on the water and trash the bad toms. good luck with them.

It is called BER (blossom end rot) and is quite common in early spring due to the plants difficulty in circulating calcium. You'll find a great FAQ detailing it over on the Growing Tomatoes forum (linked on the front of this page). It usually corrects itself once the weather settles but the FAQ will give you more ideas on things you can do for plants in containers.

The rest of the tomato is fine to eat and they will cause no problems in the compost.

Also, if you will search the forums using the search box using BER you'll find many discussions about it.

Dave

Here is a link that might be useful: BER FAQ's

Trash them if you want but most of us eat them - just cut off the bad end. ;)

Dave

You are all so wonderful! And quick, too!

Terra cotta pots are definitely your problem. I would never plant tomatoes (or anything really) in those again if I were you. Those pots wick water out of the soil and cause pots to dry out much faster than they would in a plastic pot. If you like the look of terra cotta then you need to put the plants in a plastic pot then put that pot inside a terra cotta one. I am sure you come home and find your plant bone dry and give it lots of water, that would definitely cause BER.

Does it look like the photo in the link below?

From the U of WI:
"Blossom end rot is a disorder associated with the temporary shortage of available calcium in the fruit. It is aggravated by soil moisture fluctuations. If water is limiting, plant growth slows and subsequently, nutrient uptake is reduced. This reduces calcium concentrations in the plant since calcium is carried through the plant in the water flow. Because calcium is carried along in the water stream, those plant parts that are transpiring most rapidly will receive the most calcium. This is often the oldest leaves since they are the largest. Developing fruit is least likely to receive the calcium it needs. Moisture stress that results in even partial wilting of the crop is enough to cause a calcium deficiency. Once moisture is available, the plant resumes regular growth but calcium uptake continues to lag and the rapidly-expanding plant doesnÂt have enough calcium to develop properly. Applying nitrogen as ammonium also appears to directly affect calcium uptake by tomato plants. This produces a reduction in calcium absorption and accumulation in the tomato leaf tissue.

The incidence of blossom end rot is reduced by providing even moisture and avoiding excessive nitrogen fertilizer applications. Although varieties do differ in susceptibility, there are currently none with sufficient tolerance to provide dependable control. Timely and repeated spraying of tomato fruit and foliage with a dilute solution of calcium chloride has been reported to prevent blossom end rot but the benefits are often variable."

Sue

Here is a link that might be useful: Photo: blossom end rot in a tomato

That's definitely it!~ Thank you.