The Pacific Grove California Monarch Butterfly Sanctuary was one of the attractions Bill and I visited while we were in Monterey, California, over the holidays.
It was disappointing because the number of overwintering monarchs had appeared to be much less than when we visited January 2011. On our earlier visit we saw large numbers of monarchs huddled together on pine, eucalyptus and Monterey cypress trees.
Monarch butterflies are well known because they migrate across the North American continent each spring and fall. On their way north, four new generations of butterflies are hatched. The fourth generation migrates south to their wintering grounds and begins the cycle the following spring.
Monarchs west of the Continental Divide winter in forests on the Pacific Coast of central California, while those in the east winter in forests in Mexico.
The statistics for the winter of 2018-19 showed an 86% drop in monarch numbers in California from the previous year. Possible causes in the decline were fires and drought in the area.
The monarch population wintering in Mexico last year was the largest since 2006-07; they occupied 6.05 hectares of forest. By comparison, wintering monarchs occupied 18.19 hectares of forest in 1996-97.
Monarch decline had been attributed to herbicide-tolerant crops in the Midwest and declining numbers of milkweed plants. Milkweed (Asclepias) is the only plant the monarch uses for a host plant. Monarchs lay their eggs on host plants and then the caterpillars use the milkweed for food as they develop.
There are many different species of Asclepias suited to different climates and growing conditions. In recent years there has been an emphasis on planting milkweed to ensure monarchs had access to adequate numbers of host plants.
A recent study at Cornell University by Anurag Agrawal titled “Linking the continental migratory cycle of the monarch butterfly to understand its population decline” has some interesting new conclusions.
Agrawal says habitat fragmentation and availability of late season nectar plants need more attention. He also says planting milkweed is a good thing, but its not the whole answer.
Agrawal found in his study that monarch numbers were not down at the end of the summer, but by the time they got to Mexico their numbers were reduced. His study examines what monarchs need at different times of the year. In Texas, they need milkweed to lay their first generation of eggs in early spring. In the fall when monarchs are migrating through our state, they are no longer reproducing, so milkweed is not needed. Instead they need water, nectar and trees for protection and roosting. They also need interconnected habitats as they travel south.
Texas has been called “the most important state” in the monarch migration, according to Chip Taylor of Monarch Watch. It’s important for Texas gardeners and municipalities to provide fall blooming plants, water and shelter so the monarchs have enough fuel to arrive at their wintering grounds in Mexico.
Now is the time when gardeners are making plans for their landscapes. A diverse landscape will support more butterflies. Use a wide variety of native plants, herbs, annuals, perennials, groundcovers, shrubs and trees. Have flowers blooming from early spring to frost.
Butterflies like a flat surface for landing like you find in zinnias, sunflowers and coneflowers. Zinnias and sunflowers can be replanted a couple of times for a long season of bloom. Lantana and salvia bloom until frost and will be available when monarchs migrate in the fall.
Plant brightly colored and scented flowers in large masses. Provide shelter from the wind around flower beds with shrubs, tall native grasses and trees. Put out water in shallow dishes with a flat rock in the center. Avoid using pesticides in your flower gardens, but do control fire ants.
When many of us work together, we can provide what monarch butterflies need so future generations can also marvel at their beauty.
The January edition of “Forest Country Gardening” is currently airing on Suddenlink Channel 15, KLTX, city of Lufkin as well as on YouTube. You may find the link on Angelina County Master Gardeners Facebook page. Cary Sims was our guest, and we discussed the services Angelina AgriLife Extension provides to our community. It’s a great resource to share with your friends and neighbors.
Mark your calendar for these upcoming events:
Monthly Educational Series will be “Building Your Soil,’’ at 6:30 p.m. Jan. 20 at Angelina Extension. Attendees will learn how soil health affects productivity of your pastures, gardens, hay meadows and landscapes. Bring any soil test results you have for discussion. Program is free.
Master Gardeners Noon Program will be from noon to 1 p.m. Jan. 21 at Angelina Extension. Sims will present “Landscape Pest Control and Myths.” Admission is free and you may bring your lunch.