Inkscape: How do I create background colors/textures

Hey, (almost) first time poster.

I've been using Inkscape for a while and while forests, mountains, roads and cities are starting to look good, I have trouble coming up with a way to create generic patches of backgrounds for use on maps. I need some advice on how to make plains, grasslands, desert, etc. instead of just a white (or other color) background on my maps. I have attached an image as an example of the current map I'm working on, and how it uses a white background.

I don't have any trouble creating the areas and such, but I either a) need some good textures or b) some techniques for giving a color some generic rough/grass/sand-looking texture.

I have looked around for grass/plains textures, but from what I've found all of them seems to be "too realistic" (real grass pictures turned into a texture) and often not very good for top-down maps.

If any of you know the Pathfinder RPG module "Hollow's Last Hope" (centered around Falcon's Hollow on my map), their overland map is really what I am looking for. It's basically just a green color with some wrinkles and noise.

Again, I am looking for something that can be done more or less in Inkscape and not as an after effect on the finished map.

Thanks in advance.

The tool I use for this in Inkscape is Filter Effects. Start by looking through the Filters menu, then try looking at how the stock filters were built using the Filter Editor and try altering them.

It's not exactly intuitive, and it can be VERY slow, but it is very powerful. Keep playing with it and you'll be able to pull of some very cool effects. I recommend you go into the preferences and enable multiple thread filter rendering if you have a multicore processor. Hopefully performance should improve in the next release or two, though it's still going to be a computationally intensive feature.