Crossing the Delaware Bay on my way to New Jersey yesterday, migrating monarchs were flying past the ferry, and I was lucky enough to land at the same time as a cloud of these guys descended upon the dunes of Cape May Point.

monarch on goldenrod
Monarchs are on their migration southward right now, and in need of nectar from plants like goldenrod. Photo: Stacy Small-Lorenz
While up north, monarch butterflies produce several generations of young in the summer and are totally dependent on milkweed at the start of their life cycle.

However, migrating adults get energy from blooming fall flowers, and especially important is the abundant nectar of goldenrod along their southward journey.

An Essential Fall Nectar Plant for Monarchs

While in Cape May, monarchs especially love seaside goldenrod which thrives in sandy places. The town of Cape May Point has planted plenty of goldenrod on their dunes.

Cape May, New Jersey
The dunes at Cape May Point, New Jersey in autumn with seaside goldenrod blooming. Photo: Stacy Small-Lorenz.
The goldenrod helps to stabilize dunes and it supports monarchs on their fall migration, which seem to be coming in droves this year. In turn, the dunes are part of a natural infrastructure in the surrounding landscape that protects this beautiful historic town from storm surge.

monarchs on goldenrod
Monarchs on seaside goldenrod in Cape May Point, New Jersey. There are six, can you find them all? Photo: Stacy Small-Lorenz
I ran into Mark Garland of our affiliate, New Jersey Audubon, out tagging monarchs as part of their ongoing monitoring project.  He said this was one of their biggest monarch days in three years.

He showed me how they tag, determine the sex, and evaluate the condition of each monarch they net. This includes giving its abdomen a gentle massage with the fingertips to assess the fat score.

monarch tagging
Monarch tagging. You can tell this one is a male by its scent gland, a black dot on the hind wing. Photo: Stacy Small-Lorenz.
He let me release a monarch from my fingertip after he was done taking the data. I could tell it was a male by its scent gland, a black dot on the hind wing.

I learned that monarchs have been recaptured in Mexico that were tagged in Cape May. Amazing!

Hopefully, all that sweet goldenrod nectar will fatten these butterflies up enough to fuel them safely on their long southward journey.

And no, goldenrod doesn’t cause hay fever! That’s the less showy ragweed which bears pollen at the same time.


Take ActionSo all of you butterfly heroes out there, planting goldenrod should be the next thing to add to your butterfly hero checklist! Please retweet the tweet below to help spread the word!