Weeds

I live in the desert where no plants are supposed to grow.  When I had a lawn, without constant watering it turned brown under the summer sun.  Now I have desert landscaping and the grass insists upon coming up everywhere, around the trees and bushes which only get a minimum of water, and even through the heavy black plastic covered by rocks. I can't even pull it out because the ground is too dry. What perverse law of nature decrees that grass grow where it's not wanted and weeds crowd out the grass in a lawn?