Your grasses just look like blurry brushstrokes, because that's exactly what you've done - you need to refine it and add detail if you want to make it pop, and this is true of any artwork, not just digital drawing.
Even for this image?
Viewing post in Advice for foliage thumbnails.
There's more detail there, sure, but individual objects are hard to make out.
I look at the main area and see a gradient or two, so those must be rolling hills. It bleeds onto the rocks a bit, so that must be long grass? I see shapes that suggest shrubbery, and what appears to be a vine of some sort to the right? Looking at the image as a whole feels difficult because so many elements just blend together.
The color range is good, and even the blending isn't too bad. But it would greatly benefit from having edges around your grasses, etc, to define them better, as well as simple shading.