Q.What plants can I put near the back fence, Zone 5, that are hardy and fast growing and require little care?
I have a 50 foot wide and 5 feet tall back fence. The bushes I have had are not hardy enough. There is sun, and partial shade in some parts. Should I just put tall grasses and snow cone flowers and milk weed? Thanks for your input . Sincerely, Pam Novey

Sounds like a great garden project.
Make a good determination of the sunlight conditions to choose the correct plants.
I have listed several articles to help you start making some plant choices.
Also visit local garden centers for some regional plantings; they often have test gardens so that you can see mature plantings.
https://www.gardeningknowhow.com/garden-how-to/info/what-is-partial-sunlight.htm
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-5/zone-5-gardening.htm
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-5/planting-wildflowers-in-zone-5.htm
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-5/zone-5-hydrangeas.htm
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-5/zone-5-native-grasses.htm
https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-5/flowering-shrubs-for-zone-5.htm