Goldenrods deserve a place in your garden

A version of this article originally appeared in 2 Million Blossoms quarterly

Autumn in New England: crisp mornings, apple cider, and county fairs. Thriving in the background of this scene—overlooked, but ubiquitous—are goldenrods, their luminous yellow spires brightening tired roadways, fields, and woodlands.

Goldenrods (Solidago, Euthamia, and Oligoneuron spp.) are a group of 100+ species of asters native to North America. All are pollinator powerhouses. They bloom in succession from June through October, providing sustenance and shelter for pollinating insects long after the flower-laden days of summer have passed.

Yet, goldenrod gets a bad rep, mainly because of two pervasive beliefs. First, that goldenrods cause hay fever and second, that goldenrods are hard to control in the garden. The first is a myth–goldenrods don’t cause allergies–and the second fails to recognize that while some goldenrods are unkempt, most are well behaved. In both cases, disdain is unwarranted, so I’m here to make the case that goldenrods deserve a place in your garden.

A case of mistaken identity

Goldenrods can’t make you sneeze. They are animal-pollinated, meaning their pollen is can carried by insects, not the wind. The real culprit of hay fever is ragweed pollen, which is dry and easily picked up by a breeze, tickling our sinuses and making us sneeze. The two plants grow in similar open habitats and flower in fall, but ragweed produces green, nectarless flowers, which are never attractive to insects.

Although goldenrods also get a bad reputation for being unruly, only some species are unfit for gardens. Canada goldenrod (Solidago candensis), giant goldenrod (Solidago altissima), and grass-leaved goldenrod (Euthamia graminifolia) are indeed quick to colonize open areas and, once established, sprawl unchecked via wind-dispersed seeds and underground rhizomes. These species should be avoided in backyard gardens, but are suitable for large meadow plantings, rain gardens, or roadside restorations.

Goldenrods for your garden

For every goldenrod species that’s weedy, however, there’s at least one that’s tidy. Take blue-stemmed goldenrod (Solidago caesia) and zig-zag goldenrod (Solidago flexicaullis) that spread slowly in shade and partial sun. Or showy goldenrod (Solidago speciosa) and stiff goldenrod (Oligoneruon rigida) that form elegant clumps in well-draining soil. Planting along a salted roadway? Look no further than seaside goldenrod (Solidago sempervirens) which is tolerant of salt since it naturally grows along coastlines. And if you already have too many yellow flowers in your fall garden, add contrast with the cream-white blooms of silverrod (Solidago bicolor).

Many goldenrod cultivars have tidy growth habits, too, but not all provide high quality resources for pollinators. One cultivar that does is wrinkleleaf goldenrod ‘Fireworks.’ Pollinators love it and, true to its name, it adds a pop of color, texture and intrigue to any planting.     

To help you select the perfect species for your planting, I’ve collated a list of goldenrod species native to the eastern US that are also available in the horticulture trade.

Insect Magnet

By planting goldenrods, you support late-season insect pollinators—bees, beetles, butterflies, moths, and wasps—that depend on it. Goldenrods feed many specialist bees, like hairy-banded mining bees (Andrena hirticincta) and spine-shouldered cellophane bees (Colletes simulans), that use goldenrod pollen to complete their life cycles. Queen bumble bees and honey bees, too, feed on goldenrod nectar to build up fat reserves before winter.

Beetles also find meals on goldenrod. Locust borers consume the protein-rich pollen whereas goldenrod soldier beetles snack on aphids. Blister beetles drink nectar, but also deposit eggs on the flowers. Once hatched, blister beetle larvae catch a ride on a solitary bee back to her nest. There, they disembark, kill the bee offspring, and develop on the pollen provisions. 

Goldenrods support more butterflies and moths than any other perennial forb: 115 species of Lepidoptera eat goldenrod leaves and shoots. Countless flies, grasshoppers, thrips, and true bugs (e.g. aphids and stink bugs) devour goldenrod as well, meaning individual plants teem with insect life.

This menu of tasty insects attracts wasps. Predatory wasps, like paper wasps and potter wasps, hunt vulnerable, soft-bodied insects on goldenrod. While planning their next attack, they refuel on nectar and rest on stems. (Don’t worry, these solitary wasps are harmless to people!)

Parasitic wasps take advantage of this abundance of prey in a different way. They lay eggs, and their larvae subsequently develop, in the homes of other insects. Some parasitic wasps lay eggs in goldenrod galls, which are swollen stems containing a fly larva. Others only use goldenrods for nectar and deposit their eggs into the nearby nests of solitary bees.

Importantly, patches of goldenrod provide relief for insects on the move. Adult monarch and painted lady butterflies rely on goldenrod nectar during their annual migrations. Occasionally, they’ll spend cool nights hanging from the undersides of the leaves. As such, goldenrod is likely vital to the existence of these impressive migrations.

It is time to give goldenrods a place in the garden. Trust me, goldenrod will quickly become a mainstay in your fall garden, its luminous flowers revealing a whole hidden world of insects right in your backyard. You’ll wonder why you hadn’t planted it earlier, and the pollinators will thank you, which is certainly nothing to sneeze at.

Two-spotted longhorn bees love your vegetable garden

Two-spotted longhorn bees (Melissodes bimaculatus) love the city. This important crop pollinator is abundant in urban areas, and lucky for you, this highly distinctive bee is easy to identify. Read on to learn how to spot one in your garden (hint: look on squash and corn) and check out our field ID guide or this species profile on watchingbees.com for ID tips.

Range

Melissodes bimaculatus can be found across eastern North America, from Texas to Florida, but also as far west as the front range of Colorado. Populations occur to Minnesota and Maine.

Active Period

Two-spotted longhorn bees are active for about six weeks of the growing season—in Massachusetts, from late-June through early August—and produce one generation per year.

Appearance

Two-spotted longhorn bees are about 0.75-1x the size of a honey bee. Males are jet black, with long curly antennae, a cream-colored patch on their face, and thin white hind legs.

Female M. bimaculatus are larger and stockier than males, but with shorter antennae. They have thick brushes of white hairs on their hind legs for carrying pollen (though these hairs can be obscured by orange or yellow pollen). They also have two namesake white spots on the sides of their abdomen, though these spots are often hard to see. Females have have all black faces.

One lookalike to watch out for is the carpenter-mimic leaf-cutter bee (Megachile xylocopoides). This species is found only as far north as southern New Jersey. Females of this species carry pollen beneath their abdomens, not on their legs, and both sexes often hold their wings out at a 45˚ angle while foraging.

Male Behavior

In late-June, males emerge from the ground and patrol patches of flowers in search of females. Male M. bimaculatus are zippy; they speed through the garden, only stopping briefly to sip nectar or rest on a leaf. At night, males sleep on vegetation. They bite twigs or long blades of grass, often two to three feet off the ground, and hang on all night long with their mandibles. Males are highly faithful to particular sleeping perches, and will often sleep near other males. Maybe your garden is home to one of their adorable slumber parties!

Female Behavior

Females emerge shortly after males and get to work collecting pollen and nectar provisions for their solitary underground nests. Despite their abundance, two-spotted longhorn bees nest in obscurity; few nests have ever been documented. We suspect they nest in sparsely vegetated soils, such as those found on the margin of a garden bed. If you think you’ve found a nest, please reach out!

Floral preferences

The best way to spot M. bimaculatus is to spend time watching your garden in mid summer. Male and females drink nectar from a variety of common vegetable garden plants, including cucumbers, squash, black-eyed susans, oregano, cosmos, purple coneflowers, and zinnias. Females specially like visiting tubular flowers such as wild bergamot (Monarda fistulosa), hoary vervain (Verbena stricta), and mountain mint (Pycnanthemum).

Females collect pollen from a staggering array of plants, including asters like black-eyed susans (Rudbeckia) and cosmos, pumpkins and zucchini (Cucurbita pepo), moss rose (Portulaca grandiflora), rose of sharon (Hibiscus syriaca), and morning glories (Ipomaea purpurea).

 In addition, while studying M. bimaculatus movement in urban gardens last year, TPI scientists noticed that this species has a curiously strong affinity for corn pollen (Zea mays). This was unexpected since corn flowers have evolved to disperse pollen on the wind, not via insects*. Corn pollen is dry and light, and the flowers produce no nectar, so we figured that M. bimaculatus must have been seeking out corn flowers for pollen. Upon a closer look, we saw a female actively packing corn pollen into her scopae, i.e. the thick hairs on her hind legs. We followed up on our observations by visiting local farms in the area growing corn. Sure enough, M. bimaculatus was on corn flowers in every single field.

This remarkable association between M. bimaculatus and corn raises many more questions than it answers. Corn is not native to eastern North America—though it has been grown here for thousands of years by native peoples—so which came first? Did M. bimaculatus arrive in this region following widespread trade of corn? Or did M. bimaculatus evolve a local preference for corn pollen since few other flower-visiting insects use this resource? Regardless, we encourage you to look for M. bimaculatus on corn flowers in your garden this year.

Share your findings on iNaturalist or comment on this post! Happy bee watching.

*By collecting pollen from tall male corn flowers, M. bimaculatus is a pollen thief, not a pollinator. M. bimaculatus is not a corn pollinator since it never visits the female flowers of corn plant (the silky ears lower down on the plant), which produce no pollen and offer no nectar.

How to stop bunnies from eating your pollinator garden

Don’t be fooled by extreme cuteness: bunnies are every pollinator gardener’s nightmare. You spend precious time and money planting a native garden to feed pollinators, only to end up feeding bunnies instead. In the TPI gardens at Tufts, we face our fair share of bunny herbivory. But, we’ve also learned a few strategies for combating hungry rabbits, including a list of which plants rabbits avoid entirely. Read on to learn our tips for how to bunny-proof your pollinator garden, and visit our native plant sale in mid-June to pick up plants that will thwart the rabbits!

1. Prioritize rabbit-proof plants

The single best way to avoid having your garden munched on by rabbits is to grow plants that rabbits do not like to eat. Over the past three years, we have kept track of the fates of over 30 different species of native plants in our gardens. Although many of them, in one year or another, have been munched on by rabbits, some species have been avoided entirely. Here is the list of plants from our garden that have never been eaten by rabbits:

  • Mountain mint (Pycnanthemum spp., e.g. P. virginianum, P. tenuifolium)
  • Anise hyssop (Agastache foeniculum)
  • Bee balm (Monarda spp., e.g. M. bergamot, M. punctata)
  • New York ironweed (Vernonia noveboracensis)
  • Foxglove beardtongue (Penstemon digitalis)
  • Golden Alexander’s (Zizia aurea)
  • Goldenrods (Solidago spp. e.g. S. sempervirens)
  • Wild senna (Senna hebecarpa)
  • Joe-pye weed (Eutrochium maculatum)
  • Boneset (Eupatorium perfoliatum)
  • Cutleaf coneflower (Rudbeckia laciniata)
  • Sneezeweed (Helenium autumnale)
  • Partridge pea (Chamaecrista fasciculata)
  • (most herbs*)

2. Avoid tasty plants

In a similar vein, a great way to make your garden bunny-proof is to not grow the plants that rabbits love. Here’s a list of plants from our gardens that fed more rabbits than pollinators, and which should be planted with caution:

  • Symphyotrichum spp.asters (S. novae-angliae, S. laeve, S. prenanthoides)
  • Blazing star (Liatris spicata, L. scariosa)
  • Wild false indigo (Baptisia spp.)
  • Cardinal flower (Lobelia cardinalis)
  • Swamp milkweed (Asclepias incarnata)
  • Purple coneflower (Echinacea purpurea)
  • Cup-plant (Silphium perfoliatum)
  • Black-eyed susan (Rudbeckia hirta)
  • Sunflowers (Helianthus spp.)
  • red columbine (Aquilegia canadense)
  • Culver’s root (Veronicastrum virginicum) — not always eaten

3. Create an unappetizing display by mixing plants

We’ve found that tasty plants are often avoided when planted among distasteful plants, so try to mix and match. This means your tasty asters stand more of a chance if mixed in with lots of distasteful mountain mints, ironweed, and goldenrods. Pollinators appreciate the diversity too—the more diverse your garden, the more kinds of pollinators you will attract! And, from an aesthetic perspective, inter-mixing plants means that any rabbit herbivory that does occur will be far less noticeable.

4. Protect vulnerable plants

Rabbits love eating the youngest plants. Often, young leaves have not yet accumulated as many distasteful chemical compounds as older leaves. In our gardens, for example, young emergent sunflowers (Helianthus annuus) and cup-plant (Silphium perfoliatum) are frequently nibbled as seedlings, but are left untouched when they are larger. By protecting young plants with fencing, your garden will have the blooms you want later in the season!

The same applies to woody plants and saplings, but for a different reason. Young wood is soft, sweet, and easily chewed by rabbits and rodents. Be sure to fence young saplings in their first years–especially over winter–to prevent girdling and other herbivory that can kill your long-term investment.

5. Use your local knowledge

Keep in mind that our lists of plants (both enjoyed and rejected) reflect the tastes and preferences of rabbits in urban Massachusetts, as well as the context of our campus garden. So, to make your garden as bunny-proof as possible, learn from experience. If bunnies in your neighborhood never touch the wood asters and swamp milkweed in your garden, then by all means, plant, plant, plant. Conversely, if the bunnies in your neighborhood have a penchant for anise hyssop, then definitely don’t keep planting while expecting a different result.

Do you have tips for thwarting bunnies in your pollinator gardens? Drop us a comment!

*Although we advocate for growing native, you can add fragrant, non-native herbs like lavender, rosemary, thyme, borage, and oregano to make your garden even more bunny-proof. The nasty compounds in most mint-family plants are quite distasteful to bunnies.