BERGEN COUNTY, N.J. -- Reports are the same across our region – people are just not seeing many butterflies this summer. You can help increase butterfly populations by following the basics of butterfly gardening, covered in the first two articles of this series, but don’t stop there. Include some lesser-known components in your landscape to support these beautiful, challenged creatures.
Warming & Basking Sites
Butterflies rarely fly when the temperature is less than 60 degrees. To warm their blood and muscles used in flying, they need sun exposure and safe spots to warm up – especially important in spring and fall. Include an open, sunny space with Southern exposure in your yard as a warm-up zone butterflies. A sizable area in the center of your garden is ideal, with wind protection provided by the surrounding plants.
Butterflies will also be attracted to large, flat rocks in full sun. Stone walkways consisting of large stones will do the trick. Consider adding a boulder or two that will add visual interest to your landscape while offering butterflies an attractive basking spot.
Most adult butterflies consume nectar, and occasionally tree sap, for energy. But they also need water, as well as sodium and other minerals. While butterflies get some limited sodium from nectar, some species need even more and seek out other sodium sources. You may have experienced a butterfly landing on your arm to feast on your salty, sweaty skin.
Unlike birds, butterflies will not drink from open water – they often sip from moist areas in and around muddy puddles. This behavior is known as “puddling.” Muddy puddles offer not only moisture, but also sodium and minerals – especially important to male butterflies for reproduction. The nutrients are incorporated into butterfly sperm and transferred to the female during mating. This is thought to be a way of increasing egg viability.
You can emulate mud puddles in your landscape by filling a shallow bucket or large clay saucer with coarse sand or mud, topping it off with water to make a damp mix. Add a dash of finished leaf or manure compost, along with a sprinkle of salt, to boost the nutrients. Keep the mixture consistently moist and occasionally replenish the additional nutrients.
Some butterfly species overwinter in the larval stage, but some species, like Mourning Cloaks, overwinter as adults. To protect hibernating larvae and adults, you need to provide appropriate winter shelter in your landscape.
Some butterflies – both larvae and adults - will seek winter refuge in leaf litter – a great reason to leave leaves in place in your yard. Resist the urge to chop up the leaves – you may unwittingly chop up butterfly larvae, too.
Other butterflies will find cover under the exfoliating bark of trees. Shagbark Hickory is a native tree with loose bark that overwintering butterfly adults utilize. Log piles also make excellent winter habitat for butterflies and other sensitive creatures like amphibians. Logs have the additional benefit of adding nutrients to the soil as they decay.
Keep a log of the butterflies you see this summer and beyond – no doubt you will see your efforts paying off.
Kim Eierman, a resident of Bronxville, is an environmental horticulturist and Founder of EcoBeneficial . She teaches at the New York Botanical Garden, Brooklyn Botanic Garden, The Native Plant Center and Rutgers Home Gardeners School.