In the fall after frost you should put your perennials to bed for the winter. It is important that:
1) Cut back your perennials and old growth. Leave about 2” above ground so you can remember where your plants are in the spring. Ensure all the plant leaves are removed and stems have a clean cut.
2) Prune shrubs to shape, remove dead wood, and to withstand snow load.
3) Remove all solid leaf debris and other waste from the garden. So ensure beds are weeded and cultivated. This is especially important if you have had any insect or disease problems in your flowerbeds.
4) Add mulch to your perennial beds. Before the snow flies there should be no bare patches of ground. Use composted commercial mulches such as composted pine mulch or composted cedar mulch.
5) Spread a little blood meal around the flowerbeds to help keep rodents out of the flowerbed as well as acting as a fertilizer. This is very important to deter squirrels if you have planted spring bulbs such as tulips.
6) Place a stake in the ground where tender perennials live and then after frost has set in add additional mulch or foam domes-rose covers to protect the tender plants. Ensure to add extra fluffy snow to insulate tender perennials.