Tried & Tested; a one inch wide band of petroleum jelly around the middle of hosta pots stops villainous slugs in their tracks. Do it early in the season and It lasts all summer and as long as the leaves aren’t in contact with anything that can be used as a bridge it definitely works.  (Don’t put it near the top of the pot as its horrible to pick up the pot at a later date.) 

Aphids on roses? Take a bucket of soapy water to the rose bush and swish rose buds around in the water. You can use the same water over & over because the soap makes the aphids sticky and unable to crawl.