What is the best thing to get rid of spiders on my porch?

http://prepforshtf.com/spiders-peppermint-oil/

http://naturemoms.com/blog/2016/04/07/pest-control-essential-oils/

Spread a thin layer of diatomaceous earth around your plants, over your lawn or anywhere you notice unwanted spiders. Application is performed by either tossing handfuls of the powder onto your lawn or garden or loading the product into a dust spreader, which is available at hardware or home improvement stores.

First do you have a yellow insect light bulb in your porch light fixture? that will solve the bug problem. Then get a can of either Victor's or EcoSmart natural insect sprays at hardware stores, and I also use this product.... https://greenerways.com/collections/repellent-usda-organic-insect-repellents-and-bug-spray/products/usda-organic-natural-lawn-and-garden-insect-repellent-spray-23oz

http://pestkill.org/insect/spiders/repellent/

I use the following spray....Mix one gallon water, and 1/4 cup lemongrass essential oil in a garden pump sprayer. Spray your whole porch area...walls, doors, around windows and trim, eaves, etc. Use this about 2-3 times per year. It will help keep spiders and other crawling insects away. Our house backs up to the woods and a pond, and we never have a spider problem.

Try washing down your porch with soap water that you have added peppermint oil or extract to. Also sprinkle salt in holes around porch from time to time.