Tennessee works to boost the monarch butterfly population

Tennessee's popular seasonal effort to save monarch butterflies by preserving their habitat is underway.

Why it matters: The Project Milkweed program, led by the Tennessee Department of Transportation, is distributing free milkweed seeds while supplies last.

• Experts say boosting milkweed's presence is essential for the survival of the imperiled monarch butterflies, which use the plant for food and shelter.

The big picture: The population of migratory monarch butterflies has plummeted as development has "paved and plowed over millions of acres of milkweed," according to the World Wildlife Fund, which lists monarchs as endangered .

Threat level: Last year, TDOT estimated that monarchs and milkweed habitats had declined about 90% since 1992.

• New data found that the population of monarchs wintering in Mexico earlier this year had shrunk by 59% since last year.
• Advocates say fans of the regal butterfly species can preserve its beauty by planting milkweed in their backyard or garden.

How it works: Tennesseans can request packets of milkweed seeds online .

• Monarchs migrating through Tennessee on their way to and from Mexico will only lay their eggs on milkweed, which also serves as food for the baby caterpillars.

By the numbers: Last year, Project Milkweed faced overwhelming demand. TDOT distributed 779,601 packets of seeds.

• This year, TDOT will only distribute 350,000 packets. The program will end for the year when all of them have been ordered.

The latest: The seeds are already going fast. According to numbers from this week, orders are in for nearly half of this year's supply.

What to know: If you're growing milkweed at home, TDOT recommends you plant the seeds before Oct. 15 so that they have the best chance of surviving.