I happen to like spiders, and I prefer they stay outside. But around my RV in the park I live in surrounded by heavy gravel I have spiders EVERYWHERE, from the roof to the ground. I also have bi...
Spiders move from the trees in the breeze on a string of their web. Treating the ground will give minimum protection. I've used an Ortho spray bottle that attaches to a water hose and spray everything in site, trees, shrubs, ground. After a few days you have seriously killed off a big piece of their population... Repeat as necessary.