Dig up bulbs
After the first frost has struck and foliage begins to yellow and die, cut back the foliage, dig, and store tender perennial bulbs such as dahlias and gladiolus that can’t survive the winter in the ground in a cold climate.
Expert tip: When digging, be careful not to damage the underground bulb or tuber.
Pruning, watering and feeding
In addition to pruning your perennials, fall is a good time to feed them by working in a 4- to 6-inch-thick layer of compost around the beds. The compost slowly breaks down, releasing nutrients to the plants and improving the soil structure. Don’t forget to water!
Expert tip: Read Composting 101 to learn how to make your best compost yet.
After the ground freezes, remove old mulch and replace it with hay, evergreen boughs, or floating row covers. This extra layer protects tender perennials and helps catch and hold snow, which will also insulate the bed.
Expert tip: Mix different organic mulch types to reap the benefits of each.
In cold winter areas, stop fertilizing perennials by midsummer to encourage them to slow their growth and harden off for winter.
In warm winter areas, fall is a good time to plant perennials. Since frost and snow are rare in warmer climates, you need only keep the beds cleaned up and replace diseased or worn-out plants as needed.