Henry Homeyer: Fall flowers important food for butterflies, other pollinators and birds

By Henry Homeyer
© 2023 Telegraph Publishing

Despite my best efforts to support monarch butterflies, this year was discouraging: I only saw two monarchs visit my gardens.

I have a small bed just for milkweeds, both the common one and swamp milkweed (Asclepias incarnata). But no monarchs laid eggs there this summer, no larvae ate the leaves, and I saw no butterflies sampling the nectar.

I know the importance of food for migrating monarchs at this time of year. They need to fill up on carbohydrates, fats and protein before flying long distances. That holds true for birds, too. Right now I have plenty of flowers blooming for monarchs and other pollinators, and seed heads waiting for the birds. I’m a bit discouraged, too, by the lower numbers of birds I am seeing. Let’s take a look at some of my fall favorites that migrating creatures could be feasting on.

According to Dave Tallamy, the guru of native plants for pollinators, the No. 1 plant we should all have is golden rod – and we probably all do. There are dozens of species of native goldenrod, all popular with bees, moths and butterflies.

Many gardeners pull them out when they show up uninvited. A few species spread by root and can take over a flower bed – but others are clump-forming. Even if you don’t want them in your beds, think about leaving them at the edges of your fields or woods.

Of those species easily found for sale in garden centers, the best is Soldidago rugosa ‘Fireworks’. This plant is 3 to 5 feet tall, and stays in an ever-expanding clump in full sun or part shade, but does not take over. Its blossoms last a long time, the stems curving gently outward, like fireworks. And no, goldenrod does not cause hay fever – that is ragweed, which blooms at the same time.

Less common is blue-stemmed or wreath goldenrod (Solidago caesia). I bought a plant 20 years ago and it is blooming now in dry shade. It really has not expanded its reach very much. It grows just 1- to 3-feet tall, but usually is about 18 inches for me. It has delicate flowers that help light up a dark spot.

New York ironweed (Vernonia noveboracensis) is a tall native plant in the aster family with purple blossoms. It is still blooming for me, a month after starting to bloom. It does this by producing lots of buds that open sequentially – so it is not always a dramatic flower in a vase. But the bees love it. It is happiest in full sun in moist soil, but there it got too big for me, so I moved mine to dry soil with only morning sun. Now it is more manageable, but still a big plant. I’ve read that if you cut it back to the ground when it is 2-feet tall, it will stay smaller – but I never remember to do so. Sigh.

Speaking of asters, there are many native species, all good for pollinators and loved especially be monarch butterflies. This year the woodland asters are quite dramatic. They are a pale lavender, and grow in shady places. Elsewhere a taller wild cousin stands 4 to 6 feet tall with deep purple or pink flowers. These grow in full sun and are often seen by the roadside at this time of year. Asters of all sorts are readily available at garden centers. Ask for native ones, not fancy hybrids.

Joe Pye weed (Eutrochium purpurea) is another tall plant in the aster family. It can get huge – over 6-feet tall if grown in rich, moist soil. A named cultivar called ‘Gateway’ has longer lasting flowers and richer colors than the wild ones, though those are nice, too. Smaller varieties such as Little Joe, Baby Joe and Phantom are nice, and better suited for smaller gardens. I haven’t grown them but see they are sold as being 3- to 4-feet tall. Monarchs and other pollinators love them. All appreciate soil that does not dry out.

One tall annual that monarchs love is Brazilian verbena (Verbena bonariensis). It grows tall stalks that are remarkably tough – they grow 4 or 5 feet tall, but rarely need staking. Its flowers are in small clusters. It often drops seeds which send up new plants the following year.

Lastly for pollinators, I have to recommend fall crocus – which is not a crocus at all, but a Colchicum. This is a bulb plant that flowers on a 6-inch stem (actually the throat of the blossom) in pink, white or lavender. It sends up foliage in the spring that dies back, then each bulb sends up a cluster of blossoms in September, or even earlier. They do best in full sun and rich soil, but do fine with some shade. They like to be fertilized each year. I often see small bees and wasps buzzing around in the blossoms.

I know that many gardeners are already cutting back their flowers in preparation for winter. But hold on! Flowers with lots of seeds can be left as winter snacks for our feathered friends.

Among the best are black-eyed Susans, purple coneflower, sunflowers, zinnias, Joe Pye weed, coreopsis, sedums and ornamental grasses. Wait until spring to cut those back so that finches, chickadees, cardinals and other seed-eaters can enjoy them, especially on those cold, snowy mornings when you don’t want to go fill up your feeder.

And of course, leaving some work for spring means less work now! So leave some seeds for the birds, and enjoy watching them in the winter.