I'm making this wedding cake, and I have several ideas as to how to accomplish the look of the tree stump, but I'm not really sure what is going to get me as close as possible to this picture. It looks like a buttercream technique to me, but not air brushed, so maybe icing with 2 different colors? and then a fondant inlay for the top? Any suggestions or help would be greatly appreciated.  Thank you!!

I recently saw a cake that used this mat for the texture - http://www.jenniferdontz.com/Bark-Texture-Mat_p_1516.html Maybe you could get this to achieve the look?

That mat is awesome, but unfortunately the wedding is tomorrow and they want to avoid fondant...  My biggest question is the coloring, I don't think the texture will be a problem, but I want to get the colors as realistic as possible.

I'm pretty sure that is all fondant

Ok, but even if it were fondant, how is the coloring done?

This was done by CC member Wildorchid.  According to the description, the texture on the bottom was done with royal icing and then airbrushed.  Here is the link to the picture http://cakecentral.com/g/i/2263079/bottom-tier-is-done-with-royal-to-mimic-tree-bark-given-depth-with-airbrushing-gum-paste-leaves-and-tiny-birds-photo-by-mark-davidson/

If it were me and I had to do it the next day I'd do it with one coat of the light brown in buttercream. Then a coat of dark brown buttercream about 3 times the thickness of the first. Then smear with cake spatula. When it crusts you could lightly dust with some petal dust in a few areas with dark mocoa for some dark effects.

Ya know Goreti, I was actually thinking it looked a bit like royal icing.  Thank you so much for the help everyone!

I know it's too late now, but I do have that mold shown below (got mine from the Winbecklers at cakesuppliesplus.com) and made my daughter's wedding cake with it. I will try to attach a picture below but if that fails, I am RoxieCakes and I called it tree bark - tree stump - sunflowers so you can see the texture up close if you like.  I am glad to answer any questions but did the entire cake in chocolate ganache which worked perfectly.  I also practiced on crusted buttercream and it worked perfectly too.  I didn't try fondant but am sure it would work equally well but I am here to say that fondant is not your only option.  The Winbecklers demonstrate this mold with an airbrush but I don't have one so I painted using thinned dusts in white, black, browns,and greens.  If this works, here is the cake and Happy Baking --

RoxiesCakes, that is awesome!! I will look up that mat. Any idea if the mat could be used to do a birch cake like this pic - Or how else could this birch stump cake be made...any tips on getting the colors and texture right..thank you!!

pj22 - I personally wouldn't try the Winbeckler's mold for the cake shown below.  What you are showing is "birch bark" which is rather white-ish and smooth.  The one I did was I guess pine bark (not sure other than it looked like a tree ) which is much more rugged and distressed.  My daughter initially wanted the birch bark but since she changed her mind, I never got started. What I was planning to do was finish the cake in chocolate ganache then "paint" it in diluted white (or ivory - something along those lines) with a very stiff bristle-type brush.  In theory, this ought to work, but I have no personal experience to say that it did or didn't.  To make the carvings, I planned to dip a ball tool in hot water, dry it off, and carve.  For the knot holes, I planned to form them out of the same chocolate ganache and paint them with the same white.  However, since I can't give personal testimony to if my idea would have worked or not, I would encourage you to take some time and peruse around Cake Central searching for anything related to Birch Bark tutorials, forums, and posts.  I  know I did this myself and found lots of great examples and ideas.  PS:  If you aren't familiar with the paint technique I'm describing, use vodka or a clear similar alcohol or a clear extract of some kind to thin either an icing color and/or a matte luster dust.  If you use water, you will ruin your icing no matter what kind of icing you use.  Alcohol or extract is very important because it will evaporate quickly and not ruin your icing.  You can use a colored extract (or alcohol for that matter) and it won't hurt your icing but it will affect the color(s) you are using, so that's why to stick with clear.  I'm glad to answer any questions, but if you want birch bark (which is gorgeous), you'll need a different technique than the one I used.  Good luck and Happy Baking!!

Thank you RoxieCakes! Appreciate the help!!