To install plant support trellis netting, you'll first need to establish a framework. 

For vertical support, insert posts at regular intervals and attach the netting using 

string or twine, or even zip ties. For horizontal support, use crossbars between posts,

 then stretch and attach the netting to the bars. As plants grow, you may need to 

add more layers of netting or use clips to guide them up the trellis.