Greenhouse floor

[jean2]

You could use a gravel or crushed limestone floor as a base for the future concrete floor Many of the greenhouses that I've been in only have the stone or gravel floor. That would be much easier on your feet and legs if using it for any length of time. Another idea would be a loose-lay brick floor in a sand bed, but they tend to get uneven over time and take quite a while to install. Good luck in your venture.

Frame the floor like you were going to pour concrete but fill it with pea gravel, about three inches. It is great for drainage, and holds some moisture in the bottom to help with the humidity.