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Planting Milkweed Seeds

Monarch caterpillars feed exclusively on the leaves of milkweed, the only host plant for this iconic butterfly species. As such, milkweed is critical for the survival of monarchs. Without it, they cannot complete their life cycle and their populations decline.

Indeed, eradication of milkweed both in agricultural areas as well as in urban and suburban landscapes is one of the primary reasons that monarchs are in trouble today.

We have provided the following information about the milkweed seed pod collections efforts, along with information on how to grow your own milkweed.

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Monarch on aster
Tips for Growing Milkweed

Grow at least 5 plants together so your monarch caterpillars don’t run out of food. If you have lone plants growing around your yard, check them regularly and transfer monarch caterpillars to other milkweed, if necessary.

Most milkweed species require moderately acidic soil with optimal PH levels between 4.8 and 6.8. If you’re having problems growing milkweed, consider a PH testing kit to see if this is a problem.

Planting Milkweed Seed

Milkweed seed needs cold to break out of dormancy. This means that the way you plant the seeds will differ by season.

Fall Planting
  1. Clear away any mulch or rocks from the area which could potentially block the growth of a small seedling.

  2. Water the area thoroughly and let it saturate the soil.

  3. Make a hole about 1/4 ' deep.

  4. Measuring between holes: Make the letter L with your thumb and forefinger. Use the distance between the tips of each digit for approximate spacing. Seeds can move over winter and some won’t germinate so exact spacing now is not necessary.

  5. Place a seed in each hole.

  6.  Cover the seeds with the already-moist soil. You can place a few inches of straw or leaf mulch over the area to keep the soil from drying out.

  7. Mark your planting location

  8. 1-2 months after your seedlings have sprouted next spring, pinch off extra plants (or consider transplanting) to achieve ideal spacing for your specific milkweed.

Spring Planting


Seeds of most temperate plants need to be stratified, which is a fancy way of saying that they need cold treatment. The purpose is to trick the seeds into thinking they've been through winter.Without stratification, the percentage of seeds that germinate is usually low.

To stratify seeds, just put them in a moist paper towel, then into a plastic bag and leave them in the refrigerator. Check on them occasionally; they may start germinating sooner, and you'll want to plant them then.

After a stratification period of 3-6 weeks, the seeds can be planted in warm (70˚F), moist soil.


Once the 30 days are complete, it’s time to plant the cold stratified Milkweed seeds. You can either grow indoors, or plant directly outside

Planting Milkweed Seed Outdoors

When planting seed outdoors, It is best to plant the seeds as early as possible, but make sure that you plant after the last frost.

  • Water the soil before planting the seeds to avoid washing away the seeds.

  • Plant seeds in damp soil about 1/4" deep.

  • Mark the location of the seeds.

  • The seedbed should be kept moist until germination.

  • As the seedlings become established, it is important to avoid watering too much or too little. A light watering each day until roots are well established (7-10 days), preferably in the morning, should be sufficient.


Growing Milkweed Seed Indoors

  1. Planting - Pots that can decompose are best such as paper or peat. This way the entire pot can be planted, avoiding harming the delicate roots. Fill the pots ¾ of the way with a 'seed-starting potting soil' and gently add water.  Water should be able to drain through the pots. Once the soil is damp, place 1-2 cold stratified seeds into each pot.  To finish, place 1/4 inch of soil on top of the seed.

  2.  Watering - Gently water the planted seed to give additional hydration. The best way to water is from the bottom up:  use a flat pan under the peat pots and add a half inch of water to the bottom of the tray.

  3. Don’t overwater, as it can cause fungus. Water every day, or every other day as needed. The best way to test the soil dampness is to touch it; if the soil seems dry then add water, but if it’s wet, wait for the soil to dry out before adding more water.

  4. Light Requirements - For the next few weeks, make sure your Milkweed is either in a sunny window, in a green house, or under a grow light. Milkweed needs lots of sun and warmth to grow.

  5. If you’re using a grow light, make sure to lower the bulb closer to the pots, or your seedlings may become leggy as they stretch to find the light.

  6. Ideally, a sturdier stem is better. Some people have good luck pointing a gently circulating fan towards their growing seedlings, in an effort to strengthen young plants.

Transplanting Seedlings

The best time to put in Milkweed plants is in early spring after the danger of frost has passed. Transplant Milkweed when the plant is no larger than 3 inches tall, as many varieties produce a long taproot that cannot be disturbed. In most cases, the transplanted Milkweed plant will go though some shock and could lose all of its leaves. This happens, so don’t panic! The plant is trying to establish its roots and will eventually grow leaves again.

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Growing Milkweeds from Cuttings

All milkweeds are perennials and some can be grown from cuttings. Cuttings provide a way producing new plants in a relatively short time and it avoids some of the difficulties of starting plants from seeds.

  • To start cuttings, cut the stems underwater

  • Then coat the bottom of the stem with a strong rooting hormone.

  • The stems should be placed in sand, vermiculite, or potting soil that is kept continuously moist.

  • Cuttings can usually be transplanted in 6-10 weeks.

Survival is best when cuttings are made from green stems (1/3 inch diameter) obtained from plants fertilized two weeks earlier.


Milkweed Seed Collection:

Sept 1 - Nov 12

Pollinator species are experiencing population declines across the United States. In particular, monarch butterfly numbers have drastically declined here in Ohio and in the wintering grounds of Mexico. In response to this decline, the Ohio Division of Wildlife and other partners have created the Ohio Pollinator Habitat Initiative (OPHI) to educate the public and help create beneficial habitat for pollinators such as the monarch butterfly. OPHI formed after the 2014 petition to list the monarch as federally endangered or threatened. The group’s primary focus is to find opportunities and other partners to assist in the efforts to create habitat.


To help foster the creation of habitat for the monarch butterfly, OPHI, in cooperation with Ohio Soil and Water Conservation Districts, is organizing a Statewide Milkweed Pod Collection this year starting September 1st and ending October 30th. Milkweed is essential to the survival of monarch butterflies (it is their only food source!), and Ohio is a priority area for monarchs. The monarch butterflies that hatch here in the summer migrate to Mexico for the winter and are responsible for starting the life cycle all over again in the spring. 

All milkweed pods collected during this time will be processed by OPHI partners and all of the seed collected will be used to establish new plantings and create additional habitat for the monarch butterfly throughout Ohio.

When to collect seed pods

Collect milkweed pods from Sept 1 - Oct 30 if they are mature (brown seeds within typically a brown/cream seed pod, not white/cream seeds in a green seed pod).


​How to collect seed pods

The Ohio Pollinator Habitat Initiative reminds us of several things to keep in mind when collecting seed pods:

• It is best to pick the pods when the seeds contained within them are brown. Do not collect them when they are white or cream colored as they are not matured. The pod is ready to be picked when the seam of the pod opens with gentle pressure.

• As pods are collected, be sure to wear appropriate clothing as well as disposable gloves.

• Place collected pods in paper bags or grocery sacks. Do not use plastic bags as they attract moisture.

• Keep seeds in a dry, cool area until you can bring them to the Butler SWCD Office.

• If you collect milkweed varieties other than common milkweed, please mark the species on the bag along with the date and county collected in.

• Collecting pods will not affect milkweed populations in areas where they are already established.


Where to take your Milkweed Pods

Drop the seed pods off at the:

Butler SWCD office

1802 Princeton Rd, Hamilton, OH 45011.

Anyone is welcome to drop off milkweed pods between 8 am and 4:30 p.m., Monday through Friday.  For pod collection stations in other counties, check with your local SWCD. 

Recordings of Presentations

Jan, 2020

Pollination Syndromes

July 21, 2020

Part 1: Bees of Ohio

Part 2:  Trees for pollinators and Growing in Seasonal High Tunnels 

Sept 16, 2020

Part 1: Butterflies, skippers, and Moths and Host plants for caterpillars

Part 2: Starting Plants form Seed

Part 3: Pollinator Garden Pests and Upcoming pollinator volunteer events. 

May 2, 2022

Dealing With nuisance wildlife & Dragonfly Gardening


February 7, 2022

Garden planning for wildlife & The return of native wildlife.


Winging It: Backyard Birds Resources

Learn about the birds that visit your backyard, and find out how to attract more during these recordings of recent virtual workshops.

Recordings of Presentations

Common Bird of SW Ohio recording from Feb 23, 2021  (1 hour 20 mins)

Creating the perfect bird friendly habitat recording form Mar 1, 2021 (1 hour 12 mins)



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