well I don't know but I asked Monsieur Google, and he said Google Sketch Up v7 - want to have a look?

I did the same thing and there are plenty out there!
There is also a virtual garden planner on the BBC site.

Thanks will have a closer look at them. has any one used one in particular?

I used to use a 3d garden planner. Take a picture of a garden, then place pictures of plants on top. I did have to import the pictures from google images. But unfortunately the programme is no longer available for the up to date computers. So I do much the same on a photo with Paint, use pictures from the net, and paste on top to the size you want. You can see what I have done on the link to my web site. Below the head plan is a picture for the new border.

https://sites.google.com/site/juleshlangfordceredigion/home/june-2010-onwards?pli=1

I've never been able to get the BBC version to work, Meanie - just sits there, looking at me...

That'll be because like me you need an Adobe doo dah thingy, and probably like me won't be pressured into downloading it!!!

just tried the BBC version, don't bother plants so limited but I guess that is what you get with free versions.
Like the idea of overlaying pictures seems alot of hard work but I guess it gets easier the more you do it.