This maybe be a roooolly stupid question but I haven't been able to find and answer to this anywhere!

Quest:  To use a grass brush to make realistic vegetation. 

I understand that you can choose the foreground and background colours in your colour palette to simulate the dark lower stem and lighter leaf tip for example and have done that with greens (looks ok........) BUT can you apply a gradient to your brushes for even more colour variation?

Hope you can help .........      :huh:

Hm, well... maybe someone else can answer this better, but this was the first thought that popped into my head... Put your grass layer on a new layer. Stamp it with any color (white, black, whatever). On your layer pallet, lock the transparent pixels with the little button that says "lock" and use your gradient tool to fill the grass with your green toned gradient. I tried this real quick and it gives a nice result. Hope this helps!

Or make a new layer, draw the design and then choose gradient adjustment layer. Hold the ALT key while choosing the adjustment layer and in the dialog box click on "group with previous layer". Now you can play interactivly with the gradient and change it or tweak it any time, even after closing and opening again the saved document :)

Tihomir