Blending help

[Afarseqim]

Trying to connect these two photos, but the green stripe in the middle there is giving me a lot of trouble. I'm a bit of a novice. Any ideas for how to make this more of a gradient?

I tried using the gradient tool, but I don't know how to give it the grainy texture of the rest of the photo, so it looks too obvious.

Grateful for any advice!
Thanks

 

[JeffK]

Select the area you want to change, use the gradient tool to create a dark to transparent or dark to light, and apply.

 

[JeffK]

Here's a 2nd version where you create a new layer on top of the original. Select the area you want to change and on the new layer, fill with the solid light color.
Apply a mask to that layer and with a large soft brush, with opacity and flow set low (I used approx 25%), brush away the lighter color in the darkest area and create a soft transition to the lighter.
I felt this gave me greater control than fiddling with the stops in the gradient tool.

 

[JeffK]

My bad - just noticed you wanted to also give that area a grainy texture. You can just add a bit of noise to that selected area.
I just plugged in 1.5%. Here's a side by side - the new area vs. the existing area next to it:



And the full image again...