Fall Gardening Tips for Plants
Bulbs and Tubers
Plant spring-flowering bulbs, such as tulips, crocuses and daffodils, as early as possible in September and no later than mid-October, to allow the bulbs time to root. (Work bone meal into the soil before planting.)
Add Bone Meal and Myke Bulbs to the soil to help establish and strengthen bulbs for winter. Soil additives, such as well-rotted manure, compost and peat moss, can be worked into flowerbeds.
Remember to lift and store tender bulbs and tubers that are not winter-hardy, including dahlias, begonias, gladiolus, freesias, most lilies and gloxinia. Remove excess soil, coat lightly with a fungicidal dust, place bulbs in a container of dry peat moss or vermiculite, and store in a cool, dry area, such as a basement.
Perennials
Fall is an excellent time to plant perennials and container-grown nursery stock. (Be sure to water heavily prior to freeze-up.)
Soil additives, such as well-rotted manure, compost and peat moss, can be worked into shrub and flowerbeds.
Early fall is the best time to divide certain perennials, such as peonies, daylilies and any early spring bloomers. Fall-flowering perennials, such as chrysanthemums, should be divided in spring. Check a reference source if you are unsure of the best time to divide a particular plant.
In late fall, cut back perennials 10–15 cm above ground level. Mulch tender perennials with dry peat moss once the ground has frozen solid, to a depth of 15 cm.
Make sure to water in heavily all your plants before freeze-up.
Do not cut any flowers from roses or deadhead roses after September 1st. Allow rosehips to form, because their formation signals the plants to prepare for winter. Just prior to freeze-up, water heavily and cover with a mound of new soil or peat moss to a minimum depth of 25–35 cm. (Wait until spring to prune, and remove the protective covering in spring as soon as the native trees begin to leaf out.) Hardy shrub roses need no protection, but should be watered well in late fall.
Water hybrid clematis varieties, such as Jackmanii, heavily just before the ground freezes in late fall. When the ground is frozen, carefully remove the vines from their trellis or support and lay them on the ground at the base of the plant. Cover with 15–25 cm of dry peat moss and sprinkle garden soil overtop to prevent the peat moss from blowing away.
Overwintering Plants
If you are bringing plants indoors for winter, spray them first with an Insecticidal Soap or Trounce to prevent bringing insects into your home.
Remember that a good snowcover is nature’s best protection for all overwintering plants. Help out by throwing shovelled snow on top of flower- and shrub beds, especially under house overhangs.