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Milkweed for Monarchs

Updated: Jul 14, 2023

Did you know that milkweed is the only plant on which a monarch will lay its eggs?

Photo & Instructions Credit: Stephanie Coggins

On Sunday, July 16, 2023 local organizations came together to distribute these ecologically significant plants at the Riverdale Y Sunday Market. Thank you to Stephanie Coggins from RSDKI Views for coordination of this initiative, as well as Plant Native NW Bronx for joining the Preservancy in distribution. The plants were donated by the Inwood Butterfly Sanctuary.

Common Milkweed has a deep rhizome system and shouldn't be planted in gardens because it can crowd out other plants. However, it's the monarch's favorite food and can be included in a container garden.

Planting Instructions: Start with a 10'-14' pot, transplanting if necessary for root space as the plant grows. "For the most part, using an all purpose soil mix works well for most milkweed species...Slow release fertilizer gives the plants extra nutrients. This does not hurt the munching monarch caterpillars." Learn more

Swamp Milkweed has a more contained root system making it appropriate for gardens.

Planting instructions: part to full sun, average to moist soil; more sun results in more flowers; height 3-4’; spread 2’; willow-like leaves 4-5” long; The plant yields pink flowers June to August

Planting Your Landscape Plugs

1. Select the site/s for your plants based on the habitat requirements listed above.

2. Plant each species of milkweed in a group with individual plants about 12” apart.

You’ll be creating a patch of milkweeds that Monarch butterflies can easily find.

3. Dig a hole wider but no deeper than your landscape plug.

4. Carefully extract your plug from its container. Pulling on the crown of the

plant can break roots at the stem. We suggest carefully pushing the plug out

from the bottom,

5. Once extracted, if the root mass appears to be “tight”, gently loosen the roots

with your fingers.

6. Set the plant into the hole.

7. Fill in the hole around the plant with the soil that was removed from the hole. If

the soil lacks organic matter, compost can be added or spread on top of the soil.

8. Immediately water thoroughly. Weekly watering for a few weeks should be

sufficient until the plant is established. If the weather is sunny and hot, more

frequent watering may be necessary.

9. Mulching around the plant, such as with shredded leaves, can help retain


Seed pod control: In order to prevent the milkweed plant from spreading to undesired parts of your garden, you will need to take note of the seed pods. When you notice a pod, put a rubber band on an clip it off. Alternatively, clip the seed pods when they're green and still fully closed.

Reseeding: Your clipped seed pods can be replanted, to share with the neighborhood. Consider contacting the Inwood Butterfly Sanctuary to find out if they can use your pods to grow seedlings.

What to expect:

It usually takes a year for the plants to mature enough to flower. Plants in containers should be moved to a protected place like a shed, garage or basement to overwinter, like any container plant. Then, enjoy watching your butterfly visitors as they feast and nest in your milkweed.

Learn more from, below.

Planting-and-Caring-for-Your-Milkweeds (1)
Download PDF • 192KB

More about monarchs!

Would you like your yard certified as a Monarch Waystation?

Would you like to participate in a Monarch tagging project?

Join the project or just watch the migration at

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