As I sat down today to begin writing this week’s article, I couldn’t quite get the words to flow. After three false starts (really terrible false starts), I was about to shut down the computer and go for a walk in my garden. Just as I started to get up though, a gorgeous Tiger swallowtail butterfly flitted into view -- and stayed to visit my patch of heirloom zinnias. From there she (or he?) spent time feasting in the prairie coneflowers, the rudbeckias and the milkweed, gathering what seemed to be a good supply of nectar. As happy as that swallowtail made me, it also made me sad. It used to be that we would watch dozens of butterflies roaming our yard. Today, seeing more than one at a time is so unusual that it’s a cause for celebration.
While habitat loss and pesticide use are two recognized causes of the decline of butterfly populations, climate change seems to be another huge factor. The planet is warming, and average fall temperatures are rising, throwing off the butterfly’s life cycle. Instead of heading into their overwintering state, butterflies are remaining active, searching for hard to find food sources in the fading summer flowers. As one entomologist put it, “they’re getting old and crunchy and dying sooner.”
Keeping a healthy, robust butterfly garden throughout the fall is an essential tool in not only maintaining our current butterfly population, but also increasing it. Here are just a few suggestions Embassy designers suggest to their clients to keep their gardens going throughout the fall months.
INCLUDE FALL BLOOMERS THAT ARE NECTAR RICH
Nectar, the sweet liquid produced by flowers, is actually nature’s way of solving a supply chain problem for plants. Nectar is a “reward” for animals -- insects, birds and bats, for example -- that carry critical genetic material located within pollen from one flower to another. In their quest for this energy producing liquid, butterflies (and other pollinators) are helping to keep a wide variety of plant species thriving for humans to use and enjoy.
Primarily thought of as a sweet treat for pollinators, nectar also contains amino acids, proteins, salts and essential oils. Not all nectar is created equal however. Nectar can range in sweetness from a sugar concentration as high as 75% to as low as 15%. The quality of nectar a flower produces depends on the amount of rainfall, the ambient temperature, the time of year, the age of the specific flower itself, the size of the flower and even the time of day. Having a variety of flowers in the butterfly garden helps to make sure that high quality nectar is always available.
Most flowers produce only a small amount of nectar at a time, forcing butterflies to move from bloom to bloom in search of food. Providing large sweeps of the same flower, especially those with large landing pads, allows butterflies to easily feed without expending a great deal of energy. As an added bonus, it also keeps the pollen distribution within the species, rather than wasting it on unreceptive varieties.
Different species of butterflies prefer to feed at different levels. Some types, like the smaller sulfers, seem to prefer feeding from ground-hugging plants while others, like the swallowtails, want to feed high off of the ground. Providing a diverse plant palette encourages a variety of the winged visitors.
Butterflies also have fragrance and color preferences. Light, fresh fragrances seem to be more attractive to butterflies than heavier ones. They are attracted to bright colors -- reds, oranges, purples and yellows. Some researchers think that bright colors are easier for nearsighted butterflies to spot from further away.
Flowers and flowering shrubs that begin blooming in the late summer and then continue setting new buds throughout the fall are more likely to have a higher sugar concentration that will last longer than flowers that remain from the summer months. Native species, because of their coevolution with insects, often seem to attract more butterflies than non-natives. Research at the University of Vermont (2016) suggests that pollinators who feed at cultivars (hybrids) have to work harder to achieve the same level of energy as those feeding at the native species.
Click here to see Embassy's native fall favorites are:
PROVIDE AN ADDITIONAL FOOD SOURCE
As the nutrient value of nectar fades, fall butterflies may need an additional food source. Rotting fruit such as overripe, peeled bananas and juicy sliced oranges or strawberries are especially good sources of the glucose that butterflies need. Another important element to the fall garden is a puddling space. Butterflies, often males, gather at shallow mud puddles or sandy pools where they soak up the minerals and salt from the ground. You can create a puddling spot by sinking a shallow or slightly sloping dish into a sunny spot and filling it with coarse sand and a touch of coarse salt (Don’t go overboard! Just a tiny amount.) Make sure to keep the dish moist.
ADD A SUNNY RESTING SPOT
Butterflies are cold-blooded creatures and cannot regulate their own body temperatures. If their body temperature gets too cold, they cannot fly and must warm themselves in order to move. When fall daytime temperatures drop below 60 degrees Fahrenheit, then butterflies need a safe place to warm themselves. Light-colored, flat rocks in a sunny part of the butterfly garden offer them places to bask in the sun until their muscles warm enough for flight. Making sure that the basking spot is protected from strong winds will also help them conserve energy.
KEEP YOUR YARD JUST A BIT MESSY
Many species of butterflies do not migrate. Instead, they go into a dormant state that is similar to but not quite the same as hibernation. Having a spot in the yard where leaves, sticks and weeds are allowed to sit and decay provides a safe habitat for those butterflies that do not migrate. The leaf litter and rotting wood keep them cold, dry and undisturbed throughout the winter. Butterflies who awake early are likely to die.
By adding a fall butterfly garden to your landscape, you can help make the difference between saving or losing more of these incredible pollinators. Even though summer is upon us, it's not too late to begin. Next time join us as we look at the nectar and host plant favorites of some of the most beautiful butterflies we know.