how to fix/avoid this

This edging on the leaves happened after doing a color selection, and I have seen it happen a few times before but I dont know why it happens or how to avoid it. Anybody know?

until I can get it to upload heres the link

http://s292.photobucke​t.com …ion=view¤​t=crop.jpg

Picture gone?

finally figured out how to upload

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Did you feather/refine your selection first? It looks like you may want to play with the feather and expand/contract selection controls to avoid this edging.

I dont remember if I feathered it but I know that I didnt do any expand or contracting.

It looks like its not been feathered as mentioned before. I reckon you'd just need a feather of 2 or 3 pixels to sort that out.

What software and which selection tool did you use?

I used gimp.
And used the color selection tool. Im still learning and was replacing the sky. If you look at the pic at anything other than 100% you dont really notice it.

How about posting the original image?