I checked with a friend and he suggested that we should take the transport if we wanted to go to Chek Jawa. If we just want to roam about, there is a Scent Garden near the customer Service area to take pictures of plants like Spices...Lemon Grass, Ginger, etc.
You can get more info from this site :
Can check out Chek Jawa and Sensory Trail
Not too sure if must pay to go in....the website is a tour website.