As spring draws nearer by the day, many people in Central Oregon start to get eager for the resumption of warm weather and springtime habits. For some, gardening tops that list, and they jump the season by starting garden seeds indoors. Tomatoes and other vegetables are the usual suspects, but this year, why not add in a few native milkweed seeds to help out our local monarch butterfly population?
There are two kinds of milkweed native to Central Oregon: showy milkweed (Asclepias speciosa) and narrowleaf milkweed (Asclepias fascicularis). Both kinds were historically found throughout Central Oregon, but are now very limited in their range. Planting more native milkweed in Central Oregon can help the iconic Western monarch butterfly survive into the future.
- Deschutes Land Trust
- A Western monarch butterfly on native showy milkweed.
What?! We have monarch butterflies in Central Oregon? Yep! Central Oregon is within the migratory range of the Western monarch butterfly. Many know this bright orange-and-black butterfly because of its amazing migration from North America south to Mexico. Our monarchs, however, do not migrate to Mexico and are a separate species from the ones that do. They live only in the Western North America and make their migration from their migration as far north as southern Canada northwest to overwinter in California.
(Editor's note: The above paragraph was altered from the print version to more accurately reflect the local Monarchs' migration. An earlier version said Monarchs migrate from the Northwest, not from southern Canada)
Monarch butterflies, like many butterflies, rely on certain host plants as food sources and for egg laying and rearing. Milkweed is the host plant that monarch butterflies use for egg laying and then for providing the food young butterflies need once they emerge as caterpillars. Sadly, the Western monarch butterfly population has seen a steep decline in recent years. This past year, according to the Xerces Society, only 1,900 butterflies were spotted at overwintering grounds in California—down from 192,000 in 2017—and a 99.9% decline since the 1980s! The primary reason? Loss of habitat at overwintering grounds and along their migratory pathways where milkweed was once more abundant.
The good news is that people can help the struggling Western monarch butterfly by simply planting milkweed in their yards, gardens, or even in pots on their patios! And now it the time to get those seeds started. Here are a few tips to help grow and plant milkweed successfully:
Plant and grow ONLY native milkweed (the two varieties above). Non-native milkweed is sometimes sold at local garden stores and it can actually harm our species of monarch butterflies. Get your milkweed seeds and seed growing tips from the Deschutes Land Trust and buy your milkweed plants later this spring at a native plant nursery like Wintercreek Nursery.
Plant three to six milkweed plants together—preferably a combination of showy and narrowleaf to help provide enough egg-laying space and food for newly emerged caterpillars.
Learn more about what milkweed needs to thrive. Showy milkweed likes full sun and medium water. Narrowleaf also likes full sun but prefers well-drained soil and is more drought tolerant. Both species spread via rhizomes—so plant them where they have the room to spread!
- Deschutes Land Trust
- Native showy milkweed in full bloom.
Tend your milkweed once it is planted. Native plants (even drought-tolerant ones) will need regular watering in order to establish their roots. This can sometimes take a couple of years. Once their roots are established, they won't need as much water and should thrive in our Central Oregon climate. Milkweed also doesn't like competition (from weeds or other plants), so make sure you give it enough space to thrive.
Bonus: Plant other pollinator-friendly native plants with your milkweed! Create a monarch garden by adding other plants to your milkweed that provide nectar for monarchs and bees and other butterflies. Choose a variety of blooms that stretch from early spring through fall and use only native plants that haven't been treated with neonicotinoids (an insecticide often found on nursery plants and extremely harmful to pollinators).
Spring is coming! Seed starting offers a great window into the season and planting milkweed is one of those little steps we can all take to make the world a little better for monarch butterflies. Happy planting!
-Sarah Mowry is the Deschutes Land Trust's Outreach Director. She has worked for the Land Trust since 2005 and leads its communications and community engagement efforts.