Moon Gardens and Ways to Support Night Pollinators
From Bee City USA Committee
We think about pollinators like bees, butterflies and hoverflies, all of which are active during the day. However, not all plants flower only during the day, and not all insects are active during daytime. Let’s talk about nocturnal pollinators, and how we can also protect them when we try to protect pollinators.
You may have already experienced the inebriating sweet aromatic smell of some dusk flowering plants, like Magnolias. Well, that smell is not there just to make us want to stand around them and never leave… In fact, those dusk smells have evolved to attract pollinators of those flowers, that are also active at night. Although the smells are often what makes us realize they are around, it is not just the smells, but also other traits of these flowers that make them attractive to nocturnal pollinators; these flowers are also often light in color. When thinking about diversifying gardens to also support pollinators, the idea of moon gardens is a great one to consider. Moon gardens are gardens that include species that bloom at dusk/night and that support pollinators that are also active during those hours. Some natives in our area that can serve this function are native Magnolias, evening primroses (Oenothera), wild native tobacco plants (Nicotiana) or Yuccas (several species are native to Maryland).
Flowers of Nicotiana, a genus native to Maryland. Photo: D. Hartley (CC0).
Because they flower at dusk, these plants usually attract moths that are also active during those times, even though some pollinating beetles also sometimes join the party. Some cool moths that are supported by these plants are the super specialized tiny moth of genus Tegeticulla, that actively pollinates Yucca flowers in the night and, after pollinating, lays eggs on the flowers to have their larvae feed on the seeds. Other cool pollinators of some of these plants are hawkmoths (or sphinx moths), which are active at night and have very long tongues that they use to collect nectar from often tubular white flowers of dusk-blooming plants such as the native wild tobacco Nicotiana.
A consideration when establishing moon gardens and seeking to support night pollinators is to take into account that artificial night lights can strongly disturb a night pollinator’s ability to find the plants in the night. In fact, night lighting can disorient night pollinators (and other nocturnal insects, like fireflies), attracting them to the light sources, and on the one hand making them unable to feed (because they do not find the flowers) but on the other hand also exposing them to higher predation (because they become easier to see). Another indirect consequence of the presence of artificial night lights, is that if the pollinators are attracted to lights in such a way, the plants that need them to be pollinated will not get pollinated. To contribute to supporting these pollinators (and independently of whether a moon garden is established), it is recommended for non-essential outdoor lights to be turned off when not needed. Besides reducing the power bill, this will also help pollinators and plants that are busy at night find each other to get food (for the pollinator) and be able to reproduce (for the plant). If leaving lights on is unavoidable, one should consider the intensity that is being used. Can the light be dimmed to a lower intensity? Could they be filtered to display a color that is less disruptive to insects? The Xerces Society has put together a really neat guide on this, and we encourage you to consult it.
Sphinx Moth. Photo: J. Fortnash (CC0).