Inkscape: How do I create background colors/textures

[Flayra]

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.