Milkweeds for Monarchs
Introduction
What is milkweed and why are we growing it?
Milkweeds are a type of perennial flowering plant famous for attracting and feeding the iconic monarch butterfly species.
Native California narrow-leaf milkweed is easy to grow. It grows 2-4' tall in full sun and can handle some shade. It’s a social plant that grows best in patches. Once it’s started at a location, it’s difficult to remove. That’s why “weed” is in its name, but that's to our advantage because we want this plant to grow abundantly at our habitats within Shoreline Park, Mountain View, California for both the monarch butterfly and burrowing owl.
How does planting native milkweeds save the monarch butterfly?
Monarch butterflies exclusively lay their eggs on milkweeds because their caterpillars exclusively eat the milkweeds. Milkweeds are poisonous to many others and also give the caterpillars/butterflies who consume it a poisonous/untasty affect to those who consume them, helping their species simultaneously avoid predation and have less competition for resources.
How does planting milkweeds save the burrowing owl?
The burrowing owl’s diet consists of eating bugs, including butterflies, and small rodents. Adding more native plants to their habitat creates more resources and shelter for the bugs and small rodents that the owls consume. More food for the owls means more owls!
Why grow milkweeds to transplant at the migratory monarch butterfly & burrowing owl habitats in Shoreline Park?
Burrowing Owl Billows and Lake View Land are habitats for the burrowing owl and migratory monarch butterflies within Shoreline Park, Mountain View, California that I (Aisha of Aisha with an Eye 501c3 nonprofit) rallied volunteers to grow milkweed from seed to transplant at. The reason we started doing this is because of the shortage of milkweeds available for purchase. The nurseries would tell us it's because there isn't a "demand for native plants," as well as the supply chain issues caused by the pandemic. Meanwhile, we'd see headlines about the decline in the migratory monarch species [source]. Thus I came up with the idea for individual volunteers to grow milkweeds from seeds at their homes in containers to transplant in our habitats when they'd grown strong enough and the season right enough.
Milkweed grown in the wild, in clumps, where they're cared for, in a location where migratory monarchs already know to visit, are more beneficial to save the species, as well as save the burrowing owl, than if the same amount of milkweed were to be grown in suburban gardens, which are fragmented by roads, trees, and buildings. They also expose the butterflies to dangers like traffic, pesticides, and heat. It's still beneficial to grow native milkweed in your own gardens, but the power of this project is in combining our efforts for the sake of doing the best we can together for the butterflies. Remember: milkweeds are social plants so do best together!
A monarch caterpillar on our milkweed at Burrowing Owl Billows. Phil Higgins, our Mountain View City biologist, took this photo in April, 2022. At the time, we'd planted 117 narrow-leaf milkweed so far (55 in 2/21, 22 in 11/20, 40 in 12/2019). All were purchased from Summerwinds Nurseries and transplanted.
While monarch butterflies are known to taste bad to birds, here’s a burrowing owl eating one. It is either an un-tasty lesson it’s about to learn or evidence of an acquired taste.
Credit: Paul Ayick/Audubon Photography Awards
Instructions
If you'd like to join this project, we provide you with the containers, seeds, and support, while you provide the soil, space, and care.
After reviewing the instructions and joining the mailing list (below), email me (aishawithaneye@gmail.com) and I'll connect you with receiving your supplies!
Optional Cold Stratification
Exposing your seeds to the cold before planting them can help to stimulate the growth cycle by simulating cold winter weather. To do this, put your seeds on a wet paper towel, in a plastic bag, and in the fridge for 1 month. This step is "recommended but optional." As this is the first time we're trying this project, please experiment (you could try some seed with cold stratification and some without) and report back with your results.
[Source: for the below photographs and steps]
- Sprinkle Seeds on Wet Paper Towel
Wet a paper towel and gently wring it out so it is damp but not dripping with water. Too much water may cause the seeds to mold inside the bag.
2. Fold Paper Towel into Quarters
Sprinkle the seeds onto half of the paper towel first so the seeds will not overlap when you fold it.
3. Place into Ziplock and Fridge
Label the bag with the date and type of seed. Set a reminder on your phone or calendar so you can remember to take them out in 30 days.
Planting Seeds and Caring for Plants
Make sure you have enough outdoor space in full sun for all your 1-gallon containers. Your containers will stay in this location throughout until we transplant them.
Fill 1-gallons with DAMP soil to 0.5 inches below rim. Mix soil with water before or while filling containers to create DAMP soil.
Create 3 holes with your finger ⅛-¼ inches deep, spaced 2 inches apart in a triangle at the center of your 1-gallon container.
Drop 5 seeds per hole.
Lightly cover holes with soil (not more than ⅛-¼ inches).
Press soil over seeds so it’s gently packed. Do not leave any of seed exposed to air.
Spray-water once a day, everyday. Do not let soil dry out, but also do not overwater. The goal is to keep seeds MOIST until germination, but NOT DRENCHED.
Expect to see sprouts in 7-10 days.
After you see sprouts, focus on watering deep (to get to the roots) and less on the surface (don’t use a spray bottle anymore). Water every 2-3 days in full sun. Tip: You can determine how much water your gallon needs by weight. If it’s too light, you need to water. If it’s already as heavy as it was the last time you watered, skip watering this time and check again later.
If sprouts do not rise from all 3 holes within 7-10 days, seeds can be re-added to the vacant spots to try again.
Expect milkweed to grow up to ~6-inches above surface in the fall. Then the top-growth will “die-off” over the winter, but the root-ball will remain. This is called “going dormant." Keep watering lightly. Beginning in the spring, the top-growth will return and this will be when we transplant.