Posted: 17/02/2017 at 15:12
I bought a 14x10 second hand greenhouse 3 years ago and it's the best money I ever spent. Lengthens your growing season and allows you to overwinter cuttings easily.
You are probably too late this year to do much in the way of seed sowing until the autumn but the advice I would suggest is that you think carefully how you intend to use the greenhouse before you set it up. Will you really grow tomatoes given that they take up a lot of space for a long time?
I now have a setup very similar to Perki's above with staging and a high shelf down one side with membrane & gravel underneath, a flagstone path and then soil on the other side. I have a couple of trestle tables which I put on the soil side to over winter cuttings and tender plants but in an ideal world I'd like some high shelving along that side too. I bought a few mat heaters which are a good investment for starting seeds.
I have grown tomatoes in the soil and in growbags and tbh they're a chore. Chillis and peppers are more useful. You only need ONE chilli plant though! I think it is probably best to grow these in large pots on gravel as Palaisglide suggests above. I am considering digging out the soil and doing as he suggests. I find that the soil gets very very dry inside the greenhouse so this would reduce the need to water.