I have six tomato plants which are doing really well. The three plants with the big tomatoes are giving me no trouble but the three plants with the small cherry tomatoes are producing beautiful, little tomatoes which split.
They have all been watered, equally, so why are the cherry tomatoes splitting and is it ok to eat them when they have split?
I had the same Tilly - put it down to the fact that they are so small if they get a bit of a growth spurt there's no room for expansion - perfectly okay to eat.
Think yourself luck I had about 70 plants to deal with this year... I'd say as others have, over watering is your problem. As the weather cools down, reduce the amount of water you give them but still water them regularly.
One more thing as this is your first year .. dont put waste tomatoes in your compost, or next year you will be plagued with tomato seedlings popping up everywhere when you use your recycled compost ... I've been there !
Don't know the reason, Tilly, but I had the same problem with cherry toms. in France. Not here, however, maybe something to do with them ripening mores slowly? I used to pick them immmediately they were OK to eat, but, yes, it's OK to eat them when split as long as you give them a good wash - well, I'm still here!
I agree with others, that uneven watering can cause this and also fluctuating temperatures, might play a hand in it too. (A difficult balancing act to get it right)
I think its possible that your larger toms are a variety that are resistant to splitting, so maybe next year, search for a resistant varirty