Photo: Waferboard (flickr)
After a killing frost, I usually push my dead annuals such as petunias and million bells back into their pots and squash them down with my hands. If they spring back up, I sprinkle a little potting soil on top of them and leave them in the pots to winter over. Usually in the spring, the seeds have germinated and I have new annuals in my pots. Of course, they need to be fertilized regularly all summer as they are growing in old soil, but it is a good trick.
Also each fall, I try to cut back as much of my spent perennial plants as I can. Esters and mums that grow tall are especially untidy if the spring bulbs come up under them. I find that in our climate where the springs are often wet and cold that I prefer to do as much cutting down I can in the fall.
Another trick I use in the fall is to shred all of those leaves that we rake and use them, as well as pine needles, as mulch.
Another of my long-term garden tricks is to plant starts of perennials that I especially love in a number of different parts of my garden to provide insurance if the plant dies out in one location. I do this a lot with mums that I would hate to lose.
If you have time, perhaps you will share some of your tricks in the comments below.