If the beds are in the ground I'd just add the compost etc. If you've built raised beds from something they may need lining.

Hi Moon growe. Thank you for your reply. I have just built a L shaped bed using tanalised timber. The greenhouse keeps the compost in at the back and the timber keeps it in at the front. Would I have to line it or just carry on as you suggested above?

Okay I really want to check what you have written... You've created an L shaped bed which is higher than the ground level of the soil. Is the compost therefore going to be against the glass or do you have a greenhouse which has several layers/levels of brick at the bottom?

If the timber is a greenish color, the preservative used is an arsenic salt, and I would put at least two layers of polyethylene between it and the soil if you want to plant anything edible, there.

Hi Tugbrethil, thank you for your help much appreciated. I will let you know how I get on. I have tomato plants, peppers to plant.

Hi Moon growe, thank you for your comments. Sorry I am new to gardening so needed step by step instructions. Your help is greatly appreciated. Will let you know how I get on.

Julie can you answer my query... is the compost/soil going to be against the glass of the greenhouse?