as salam alaikum
there is no problem in drawing pictures of non-living creatures like trees. As far as pictures of living creatures like animals and human beings, it is permissible to draw them but they should not be put in front of a Musalli when he is praying in the direction of the qiblah. It is also disliked to have such pictures in a place dedicated to worship, especially a Masjid.
With prayers for your success.