The trees haven’t yet donned their autumn foliage, but already we are surrounded by color—field after field of bright goldenrod yellow. Sadly, most of us aren’t overjoyed by the splendor of nature’s golden paintbrush, steeling ourselves against the beauty of the goldenrod flowers and unjustly accusing them of causing hay fever. While stuffy noses and watery eyes are undeniably a problem at this time of year, little of the pollen causing these symptoms comes from goldenrod.

Hay fever sufferers are at the mercy of dry, dusty pollen blown about by the wind, which comes mostly from others plants also now in full bloom, such as ragweed. But ragweed flowers are so small and drab most of us don’t even notice them.

We have little to fear from goldenrod flowers. Goldenrod pollen is too heavy and sticky to be blown about by the wind. Instead it is carried about by the countless insects who visit the goldenrod plants to feast on the goldenrod’s abundant pollen or nectar, or—in some cases—each other.

Goldenrod blossoms teem with insect visitors. Many types of beetles feed on yellow pollen grains. As these beetles scramble about, the pollen clinging to their bodies fertilizes the goldenrod flowers, helping, rather than harming, the goldenrod. Unfortunately, one of these beetles, the innocent- looking black-and-yellow-striped locust borer, lays her eggs on black locust trees. Her larvae chew tunnels in locust branches. Infested trees often die outright or become so weakened they may snap in a windstorm.
 
Bees, butterflies, and moths also visit goldenrod. Beekeepers find their beehives filling with dark goldenrod honey this time of year. Southbound orange-and-black monarch butterflies pause frequently along their migration routes to sip the high-energy goldenrod nectar. You’ll need to look closely if you want to find a goldenrod stowaway moth feeding on the goldenrod nectar. This moth is small, and its orange-streaked yellow wings blend well with the yellow flowers. However, you’ll find the equally small, black-and-yellow lichen moth easy to spot.

Natural predators abound on goldenrod. Oddly shaped, yellowish-green ambush bugs wait patiently, hidden among its golden blossoms until an unsuspecting insect comes into reach of their powerful front legs. In the blink of an eye, the ambush bug has seized its prey, rammed its sharp-tipped, soda-straw mouth parts into its victim’s body, and begun sucking out the body fluids.

A much daintier predator is the little, pale yellow goldenrod spider. But don’t waste your time looking for a goldenrod spider web; this spider is a hunter, not a trapper. The goldenrod spider moves sideways, crab-fashion across the goldenrod flowers stalking its prey with all the stealth and cunning of a lion hunting in the jungle.

I find the gall-makers the most fascinating of all the insects found on goldenrod. The inch-long spindle-shaped galls commonly seen on the upper half of goldenrod stems serve as home to tiny moth caterpillars. The more rounded stem galls contain the young of a tiny fly. The young insects spend the winter inside the galls, surrounded by food, sheltered from the weather, and hidden from most predators.

But their lives aren’t worry-free. All too often other tiny insects move in to share the gall makers’ snug homes and may even eat the defenseless gall-dwellers. Also, hungry birds may tear open the galls to get at the tasty insects inside.

A less familiar but very common gall is caused by a tiny fly who lays her eggs on the very topmost bud in a goldenrod flower cluster. When the egg hatches, whorls of stunted leaves and flowers overlap and clump together around the immature fly forming what is called a goldenrod bunch gall. While unsightly, none of the galls seems to be harmful to the goldenrod plants.

Now that goldenrod hybrids have been returned to the U.S. by the English, why not consider planting at least one? Plant breeders have developed many new varieties. Once you plant some goldenrod, you too will be able to watch the fascinating array of insect life visit your garden.

By Janet Schmidt, UNH Cooperative Extension Master Gardener

For more information call the UNH Cooperative Extension's Family, Home & Garden Center's Info-line (toll free) at 1-877-398-4769 or send us an email. Volunteers are available to answer your questions Monday through Friday 9:00am to 2:00 p.m.

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