Got milkweed? Project aims to restore plants and monarch butterflies

Monarch butterflies have no choice in the matter: their existence is completely dependent on milkweed. And in recent years, the decline of milkweedin fields and gardens has brought a correlated decline in the monarch population.

But researchers behind anew joint project betweenthe David SuzukiFoundation and the University of Guelphhopeto restore the plantand create a safe-haven corridor insouthern Ontario for the migratory insect.

"If we don't have milkweed, we don't have monarchs," saidTyler Flockhart,a postdoctoral researcher at the University of Guelph. Milkweed is the only plant the butterfly eatsand the only plant on which it will lay eggs, Flockhart explained in an interview with Craig Norris onThe Morning Edition.

Milkweed targeted

Flockhartidentifies two main causes for the plant's decline.The first is"changes inbiotechnology:the use ofgenetically-modifiedcornand soybean that removes milkweed very efficiently from those crops. The other is urban development, which removesthe natural plants andreplacesthem withconcreteandgardens that are comprised largely ofornamentalplants."

"It's also a toxic plant," he added, "and a really aggressive grower. And that's why it's come into conflict with farmers. Livestock will eat it and it will reduce crop yields, so that's why it's been targeted for a long time to remove it from agricultural fields."

Two-step recovery

The decline in milkweed has dramatically reduced the number of butterflies, Flockhart said. So the first step is to "get more milkweedinto the ground, really, really quickly."

According to Flockhart, the easiest way to do this is toplant milkweed on land currently reserved for special purposes.

He said the project aims to create "linear corridors" by planting milkweed along roadsides, power line towers andpipeline pathways. The challenge, he said, is that these areas have been managed a certain wayclear-cutting and reducing native plantsfor a very long time.

Monarchs are not the only ones who wouldbenefit from milkweed corridors. Flockhart said other pollinators,such as hummingbirds, bees and wasps, also enjoymilkweed. These insects and birds are really important in food production and biodiversity, he added, "and these populations are in mass decline. It's quite alarming."

Flockhart envisions expanding the program to include other native flowering plants in the same areas, to benefit other pollinating insects.

The second step,he said, is to encourage home gardeners to plant milkweedinstead of ornamental plants. "It smells good," he said, "and it attracts a huge number of butterflies and bees."

"It's important this fall when you'reout at your local nurseryit's important to say to themyou want to have milkweed inthe spring," he said, so that they'll order the seeds and have them in stock for the planting season.

Agricultural concerns

In 2014, the Ontario government removed milkweed from its "noxious plant" list, which meant public gardeners and private industry wereno longer compelled to remove it on sight or forbidden from planting it. The change in classification was meant to address concerns over the decline of the monarch butterfly population and to encourage biodiversity with indigenous plants.

In 2014, Henry Denotter, an oilseeds farmer and then-president of theOntario Soil and Crop Improvement Association supported the move. He observed that if farmers had a crop-related issue with the plant they were permitted to remove it from fields but were encouraged to leave it along fence lines and rough areas.