It is really difficult to protect our plants from the pests that bother out plants. Our greatest pests are slugs and caterpillars. Additionally I don't like the idea of using pesticides. So at this time I don't protect my plants.
I do not use any chemicals or pesticides in my garden. I put crushed egg shells around my vegetables to protect them from snails. I also sprinkle sawdust around other plants. Both methods stop snails getting through. Also I will handpick snails off leaves and place them in a bucket with salt to kill them. Aphids on roses I spray off with sprayer bottle of water mixed with dishwashing detergent as this solution suffocates the aphids.