Hello. I have just returned to scale model building after a 10 year break, and want to make dioramas for some of my better efforts.

I'd be grateful if someone could help me out with some advice. Having picked a wooden base for a diorama what is the best material to create the groundscape?

I've watched videos by a talented modeller on youtube who uses ready mixed grout. He is able to put tank tracks, grass, small stones etc on the grout before it cures.

Does anyone else use this material? What other materials do members recommend? Is polyfilla equally effective?

Maybe some useful info for you here:
AMPS Central SC::Group Builds & Demos::AMPS 2013 International Show::Bases and Groundwork Seminar Slides

There are many approaches and materials that are used.

I prefer Celluclay - it's relatively inexpensive, light weight, and very shape-able. But, since it's wet it will cause warpage of your base. Be sure to seal your base well, preferably with waterproof varnish, or paint. Another point, if your base doesn't warp, the drying Celluclay will..and the edges will lift off the base. But not to worry! When all is dry just fill the gaps with more Celluclay mix. You can also sculpt a piece of styrofoam to your required contours and apply a thinner layer of Celluclay on top. A couple more tips - add earth (or whatever) color to the Celluclay mix; cheapo arts'n'crafts acrylics are excellent. I also find that I get better drying and textural results by adding white glue, or powder paste for making papier mache to the mix.

Thanks a lot for your replies.

There are some tutorials here that may give you some idea's
http://scenicfactorydio.com/
- John

Hi. I build up terrain using building insulation then cover with poly filler mixed with a water and a generous squeeze of "no more nails". This makes it a lot stronger and stops cracking. Once dried I Seal it with diluted "no more nails" which gives a harder surface and helps prevent chipping once painted. Never had any problems with this method.