[colinc]

my green house has bare soil on the floor, would I be better off putting down paving slabs down to stop the weeds. I am only usuing grow bags in the green house any way.

[ranat22]

after the last 3 years in my greenhouse i would recomend keeping it as soil if your gonna plant tomatoes...............i had mine in pots..on flags and got black spot...........so i lifted the flagstones...and dug a hole about the same width and depth as a pot(1ft d x 9" wide)
then filled it with compost....and put a good few inch rotted manure dressing on top to keep from drying out.....no problems since 

[Azazello]

Why not use some soil for your crops and cover up the bits you don't intend to use? Maybe use plastic ground cover so you retain some flexibility.

[arugula]

You could put some weed suppressing fabric down, then put slabs on top or even better gravel which might help deter slugs and snails.

[Kristen]

If you plant in the greenhouse soil you have more cropping height to the eaves.

You will have to water less often, and are less likely to have split fruit.

The plants will be less "forced" and (theoretically at least!) should taste better as a result.

Downside is that you have to replace the soil frequently - dig it out and swap it with other soil from the veg patch (or, in my case, I dig it every year and replace it with a 50:50 rotted manure and rotted compost combination)

[cooperman]

Greenhouse hygiene is imperative - at the end of the season I always clear out my greenhouse completely, wash everthing down with Jeyes fluid (inside & out)

I do the same again early in the new year when preparing to start stuff off...  I never have any problems.

The greenhouse itself has a paved path down the middle weed control fabric underneath and shingle down the sides. I grow toms, cues and peppers in large 25ltr pots and have bigs yealds and excellent flavour (but thats a different story on how I acheive that!)