Failure to Thrive

I mentioned my strange Pink Caspian tomato plant earlier this summer. This is what it looked like on June 15th:

Pink Caspian on the right

Three months later, it looks like this:

To put that into perspective:

The other tomatoes grew to 6-7 feet tall, but the Pink Caspian didn't get over two feet tall. The strange thing is, it didn't die. The leaves are still green; it just did not grow.

I don't know enough about tomato plants to have any idea why this happened. The upshot is that I now know that seven tomato plants is enough. If this one had grown and been even half as prolific as the others have been, I wouldn't have room for its tomatoes.