October 27, 2018
Perhaps this spring or summer, you planted a garden to attract and support bees, butterflies and hummingbirds — also lovingly referred to as buzzers, sippers and dippers. As fall settles in, there are secret shortcuts and practical solutions to keep your garden healthy and supportive of pollinators during later seasons.
The best fall secret shortcut is to avoid tidying up too much. What you see in your garden as dead leaves, hollow stems and flowers gone to seed, pollinators see as places to lay eggs, overwinter and get further nourishment. A second secret is to stop fertilizing and cut back on watering. As temperatures cool and daylight hours diminish, the growing season for plants is slowing. Check the Marin Municipal Water District website at marinwater.org/161/Weekly-Watering-Schedule for data on weekly water needs specific to Marin gardens.
Practical garden solutions for fall include getting rid of weeds before they set seed, pruning and dividing overgrown perennials for healthier plants, planting spring bulbs and sowing seeds that need winter chill to germinate. Blooming perennials that benefit from fall division include sedums, geraniums, dahlias, yarrow and rudbeckias commonly called black-eyed Susan. Spring bulbs to plant now include crocus and tulips; both are bee-friendly. Seeds to plant now are generally those requiring winter chill, including poppies, columbines, hollyhocks and coneflowers.
The migration of monarch butterflies in fall to overwinter in warmer climes is documented. Have you wondered what happens to other pollinators during fall and winter? The mournful dusky-wing, California sister and spring azure butterflies all lay their eggs on coast live oak. If you rake and bag all leaves, you are likely tossing future generations of butterflies, whose lifecycle can take anywhere from weeks to years to complete the four stages — egg, larva, pupa and adult. Fallen oak leaves also serve to protect the roots of plants in winter. Another butterfly found in Marin, the Western tiger swallowtail, lays its eggs on sycamore, willow, ash and fruit trees. At the end of summer, native bees mate and the female builds nests underground or in the hollow of a tree or plant stem, packing it with enough pollen and nectar for developing larva set to emerge next spring. While many hummingbirds migrate south for winter, some such as the Anna hummingbird stay year-round in Marin. Planting perennial natives that provide bloom cycles continuously through the year helps to support pollinators in your garden. For a complete list of plants that support pollinators through the seasons go to anrcatalog.ucanr.edu/pdf/8498.pdf
What blooms when
Fall is arguably one of the very best times to plant with the goal of extending flower bloom across as many seasons as your climate permits. It’s fun to explore ways to expand your pollinator garden especially as habitats continue to decline. To discover what’s in bloom when, consult the bloom calendar on the UC Davis Arboretum and Public Garden website at arboretum.ucdavis.edu. The Arboretum all-stars plant list highlights really interesting drought-tolerant plants, some of which make beautiful container plants. You can also prune up a shrub so you can plant more perennials as understory. Candidates to prune up might include manzanitas, ceanothus and coffeeberry. Understory perennials with showy fall blooms include sedums, sages and California fuschia.
Showy winter understory perennials include daphne and California poppies. Fall is also time to plant hellebores, hebes, echinacea, correa, foxtail ferns, pelargoniums, geraniums and cold-hardy succulents. The Xerces Society, dedicated to protecting our native pollinators, encourages cultivating gardens that include a diverse range of plants to provide pollen, nectar and nesting sites throughout the year. Before planting, do amend your soil by adding 2 to 3 inches of organic compost. Once all new plants are in, mulch to get better weed control and better water retention, but do leave bare areas for nesting sites.Your rejuvenated pollinator garden is a beautiful place to observe nature’s fall spectacle.