Lack of nutrients. Did you fertilize? Cool temperatures? Temps below 50F, and they just won't grow much. Is it in a container? The container may be too small and it is just rootbound, which is equivalent to lack of nutrients.

No, there was no problem there. Nutrients, fertilizer fine, weather no problem. I'm discounting all of that because I bought 3 tomato plants and although the other two are not a good size they are certainly larger than the brandywine. Although, as to your questions, the other two aren't all that big either, they are just twice as big as the brandywine.

Container size?

I've got a garden allotment which gets sun almost all day. I refreshed the stale soil of last year with sea soil, a little bit of mushroom manure and some top quality compost. Although the weather has been cool at times it never seemed to me to be cold enough to affect the plants. My other plants, beetroots, peas, lettuce, onions, beans, don't seem to be affected at all. Lettuce is abundant and I've already pulled some beets. It's just the tomatoes, especially the brandywine, that are so peculiar.

It and the others were planted directly into the ground and not in a container.

Was it cold when you planted them? Sometimes they get chilled and never really recover :(.

Linda

It's possible that the plant was mislabeled or the tag was switched somehow before you even purchased it. It may not be a Brandywine tomato plant at all.

Since it's only 8" tall, maybe it's a micro-tomato plant?

I think you are right. It's such a tiny plant with quite a number of little tomatoes on it I've been buying a brandywine for the last 6 years from the same garden centre and they have been a normal size. I suppose I should go back to that garden centre and question them, but right now I'm fascinated as to what the fruit will be.

It just about had to have been mislabled somewhere along the path from seed-saving to you. Or, it was weird, wild variants....