This is the first time I've ever grown tomatoes. I thought it made sense to grow a tomato that I couldn't easily buy in the shops so I chose a black variety. I now have the first little fruits. But (forgive my ignorance) I'm not sure what happens next. Do they get bigger? I assume so otherwise they are just like berries. And how do I tell when they are ripe? They are black already so won't change colour...