You can grow tomatoes from seed like I’m doing – or you can buy the plants ready grown and ready to go into the greenhouse. It is less effort buying the plants but seeds are fairly cheap and as long as they don’t die from frost they should be ok.
A problem with growing from seed – well for me anyway, is being pessemistic about how many seeds will come through. Virtually all the tomato seeds I’ve planted this year have come up – so now I’ve got 20 plants in my greenhouse. This is nice in a way as I’ll have plenty of tomatoes to use, but also means I’ll need some extra tomato food!

I can recommend unwins for buying plants from. They’ve got a great choice of greenhouse plants from different types of tomatoes, peppers, chilis and Aubergine plants.
Buy greenhouse plants online at Unwins

The tomato seedling in the picture is of a plum tomato called San Marzano. The true shape of the tomato leaf is now showing – contrasting with the smooth leaf shape of the first two seed leaves.
It’s always worth bearing in mind you can buy plants in case you have a disaster in the greenhouse!