You been smoking way to much!

There is weed there, and tomatoes and mellons and strawberrys and tobaco plants. I took the photo for another thread, I noticed it had the cucumbers in the picture and I dont have any way to take another one at the moment so thats why I had to use that photo.

Anyway, this thread is about the cucumber plant, I know I have to pick them when there ripe but how do i know when they are ripe?