One of my favorite times of the year occurs when the butterflies arrive and grace my gardens.  When I installed my gardens a few years ago, it was with the intention of attracting Monarchs so that I could teach my daughter (now 9 years old) about this gorgeous butterfly and the importance of supporting our pollinators. 

This interest continues to strengthen each year as we support generations of Monarchs that move through our gardens and then off into the world. 

There are two critical elements for attracting butterflies: 1) a host plant and 2) a nectar source.  If you share an interest in inviting either Monarchs or Swallowtails to your garden, I will show you how to attract them, support their young and nourish the adults. 

Monarchs

Host Plant

The Monarch is very picky when it comes to its choice of a host plant, but for good reason!  The one, and only preferred host plant for the Monarch, is Milkweed, and it was chosen due to the milky sap that young Monarch caterpillars ingest, which offers protection against hungry predators looking for a caterpillar snack. 

One thing that I have noticed is that if you have little sprouts of milkweed that pop up at the edge of your flower bed, you will likely find a good population of eggs under the tiny leaves.  The reason Monarchs use the smaller plants at the edge of the garden is because the eggs, while further away from the larger host plant, are also further away from eager predators who monitor the host plant for eggs and caterpillar.  So, before you thin out your garden, check under the leaves for eggs!  Monarchs will also lay eggs near Butterfly Weed which caterpillars will feast on.

Lifecycle

Adult Monarchs usually show up in May, scouting the area for nectar sources and for their host plant.  Monarchs have 4 generations.  The one that shows up in May were born in the prior year, at the end of the season, in August or even September, and have made the great migration back home, from Mexico. 

●      Eggs take 3-5 days to hatch, depending on temperature. The warmer the weather, the quicker the egg will hatch.   

●      As the caterpillar grows, it will molt its skin and move into the next instar stage for a total of 5 stages which usually take around 2 weeks to complete. 

●      At the conclusion of the 5th instar stage, the caterpillar will move to a high location, hang upside down and form a “J” which is known as a pre-pupa stage. The caterpillar will shed its final skin and will encase itself inside a chrysalis where it will slowly develop into a butterfly

●      The butterfly will complete its development 8-15 days later, again depending on temperature. 

●      When the butterfly emerges from its chrysalis it will look small, its wings accordioned up near its center.  The butterfly will slowly pump its wings to dry the wings and to start blood flow until the wings are fully expanded. This process takes less than 30 minutes then the butterfly is ready to go find a nectar source and a mate and the cycle starts again. 

Swallowtails

Whenever I spot a Swallowtail Butterfly in my garden, it is a special delight and while in previous years I have focused exclusively on attracting monarchs, I have decided to make a concerted effort to attract Swallowtails which will provide a great reason to swing by my local garden center again! 

Host Plants

To attract Swallowtails to your garden, plant members of the parsley family:

●      Parsley

●      Dill

●      Fennel

●      Carrot

●      Queens Anne’s Lace

●      Golden Alexander

●      Common Rue (or others in the Rue Family)

Lifecycle

Unlike the Monarch, there are only 2 generations of Swallowtails: those active between Mid-May and Mid-June and those active in early September and will overwinter until the next year. 

●      The eggs take 4 to 9 days to hatch, depending on temperature. The warmer the weather, the quicker the egg will hatch.   

●      As the caterpillar grows, it will molt its skin and move into the next stage for a total of 4 stages which usually take around 2 weeks to complete. 

●      Once the caterpillar enters the pupal stage, it will take 9 to 18 days to emerge, unless it is in the generation that overwinters

●      The caterpillars that overwinter in their chrysalids can protect themselves from freezing by making glycerol which is like anti-freeze

Finally, to attract any pollinator to your gardens, including butterflies, a diverse selection of nectar sources is a must:

Common Nectar Sources:

To help attract and support future generations of butterflies year over year, set your garden up to have continual blooms throughout the growing season.  Older generation butterflies will need your help as the weather cools by having access to late blooming nectar sources as fall approaches.  When in doubt, or if your garden is closing shop early, stick some discounted, end-of-season annuals in pots, the butterflies will thank you!

Photo credits: Cheryl Schultz, Washington State University; WSU Newsletter (1), www.flickr.com (2), Maryland Department of Natural Resources (3), Alabama Butterfly Atlas; usf.edu (4), Wisconsin Horticulture, Division of Extension (5)