Smooth transition between spawners

[Mussorable]

Hi, how I can make a smooth transition between two texture spawners? For example if I have a forest and desert close to each other and when I'm trying to make a more smooth transition - I have only two textures(forest/desert sand) with half of opacity in both textures. How I can make a really something like smooth transition? For example, I've read about Jitter, but on texture I can't find this option at all 😞 

If I'm trying to make noise or smooth - its applying for all terrain instead of place where I need. Thx for the info.

[Bryan]

You would want to use noise and bleed it into each other like this: