How to fill an area with a Pattern

Hi guys,

I need your help! Since months I am trying to find a proper solution for my problem:

Im drawing mushrooms in Adobe Fresco. Many of them have some specific patterns on their stem, like a net or some flakes.
It takes hours to draw this by hand, especially cause I need to draw about 10 different mushrooms.

So 

I tried to create pencils with Adobe Capture, but it doesnt look real (Photo 1). I tried to use Adobe Illustrator for redrawing pictures with the texture and that did not work out as well. 

How could I solve this problem? I have full creative cloud so I could use other programs as well. 

Sooo happy about any idea or help.

Thanks!