Preparing the Garden for Winter

My sunny, East Bed looking a bit chaotic, to say the least!

Fall is upon us and I am officially in that limbo phase of waiting for the first killing frost to turn many plants in the garden to black mush. Leaves and pine needles are beginning to fall, but not yet enough to pick up the rake. Another shipment of Fall-planted bulbs just arrived. Enough for at least two days’ worth of planting effort. But, first I need some of the perennials to die back to expose opportunities to tuck in more Allium bulbs.

Meanwhile, the Goldenrod, Honeysuckle, Persicaria, Japanese Anemone and Hydrangea are still covered in bloom and native bees. So, the garden cleanup hasn’t yet hit the “urgent” phase.

Certainly by the first weekend in November, the work will begin in earnest to put the beds to sleep for the winter. Some plants will be cut down completely, others only partially, and others will be left to stand throughout the winter. All beds will receive an insulating layer of leaves and leaf mulch!

Here’s my Plan of Attack to tidy up a bit while protecting bio-diversity throughout the winter. What not to do is more important than what to do!

As always, remove any diseased stems and fallen leaves completely from the garden and dispose of these - do not compost! This includes bee balm and phlox that may have succumbed to powdery mildew. Also leave 2 or 3 inches of old growth as a marker for identifying your plant locations next spring.

Cut back entirely as plants completely die back:

  • Perennials, including: Joe Pye Weed, tall Phlox, Filipendula, Japanese Anemone, Goldenrod, Baptisia, Iris and Day Lily foliage, Hosta foliage

  • Astilbe can be easily pulled or raked away, exposing perfect planting areas for spring blooming Allium bulbs

  • Tall annuals, including Tithonia and Verbena Bonariensis (the latter reseeds profusely, so cutting down and removing the seed heads will prevent a gazillion seedlings next spring

  • Herbs, sedums and annuals, including the nasturtiums that have completely rambled through the East Garden bed, threatening to smother the lovely Amsonia Hubrichtii that will soon turn golden red!

cut back partially, leaving new basal foliage produced in the fall:

  • Monarda (bee balm): remove dead stalks and gently remove fallen leaves that may have been diseased with powdery mildew

  • Achillea (yarrow): remove dead stalks and foliage but leave anything that’s green as the plant continues to produce basal foliage which will help protect the plant’s crown throughout the winter

  • Shasta daisies: same approach as bee balm and yarrow! Fall is a great time to divide and share or transplant daisies.

Do Nothing:

  • Many perennials over winter more effectively if clean up is put off until Spring, including: Agastache (hyssop), Heuchera, Hellebores, Moss Phlox, European Ginger, Vinca Vine.

  • Penstemon: these jewels of June will have a better chance of surviving the winter if all foliage is left undisturbed until Spring when new leaves emerge in early May.

  • Ferns will die back naturally and dried fronds help to protect the shallow rooted plants survive our tough winters. Fern debris is easily cleaned up in the Spring.

  • Ornamental grasses, including Hakonechloa, should be left alone until spring. Cut down completely in late April to about 3-4” before new shoots emerge.

leave for wildlife:

  • Echinacea (coneflower), Black-eyed Susan provide nutritious seeds for Goldfinch throughout the winter.

  • Groundcovers provide habitat and cover for birds and beneficial insects.

  • Climbing vines like Honeysuckle and Clematis retain their dried foliage throughout the winter, providing cover and protection from the elements for small birds.

  • Fallen leaves and pine needles provide insulation for butterfly larvae and beneficial insects, including native bees, that over winter in plant debris. These creatures are essential as pollinators and as a food source for our native wild birds. If you “vacuum” your beds clean, you circumvent the Circle of Life in your garden next spring.

In the next issue of Garden Talk, we’ll explore the benefits of applying fallen pine needles and leaf mulch to insulate tender plants and to provide essential habitat for over-wintering butterfly larvae and native bees!