Take pictures.
Mark your plants.
Make sure plants are watered in October and November.
One inch of water/week
Many perennials can be left to be cut back in the spring, especially those with bountiful seedheads such as coneflowers or rudbeckia, as the birds will enjoy their seeds through winter. However, there are some perennials which are best cut back to avoid spreading diseases—such as powdery mildew—especially bee balm, phlox, and Hosta. See which perennials to cut back. When cutting back, wait until the ground has frozen hard and the foliage has died. Leave about 3 inches of stem and mulch them with a thick layer of leaves or straw.
Fertilizing after September 15th can encourage new growth that won’t have time to harden off before winter. Once the ground is nearly frozen in late November and December, however, you can apply fertilizers so that they will be available first thing in the spring.
Thorough clean-up can prevent or at least reduce the intensity of disease and insect problems the following season. Here are just a few examples. Leaves that may carry the spores of fungi should be thoroughly removed from your property if at all possible.
Thorough clean-up can also prevent rodents from nesting for the winter at the bases of shrubs and perennials and using the plants as a convenient winter food source.
Selective clean-up can mean winter beauty. Ornamental grasses, Echinacea, or Sedum look lovely with a dusting snow. Think, too, about whether leaving some plant material will provide food for winter birds.
Because they don’t compact down like other leaves and allow air to enter and moisture to escape even when they’re wet, oak leaves and pine needles make terrific mulch. Don’t throw them away without considering their usefulness. Note that both can increase soil acidity.
Temporary mulch can go a long way to protect more tender plants over the winter by insulating roots against the late winter damage of the frost-heave cycle. The best mulches are pine needles, oak leaves, evergreen boughs, or bark mulch in a pinch. Research your plant first – for example, some perennials resent having their crowns covered with anything that retains too much moisture. Don’t put down protective mulch too early. You may be making a perfect winter nesting site for rodents that view the protected plant as a convenient food source. Instead, wait until the ground freezes or is about to freeze, usually no earlier than late November. Protective mulches must be removed in the spring when the soil warms up, usually no later than April 1.
References
The Garden Club of Norfolk, Inc. 