How To Grow Milkweed from Seed

How to Grow Milkweed: A Comprehensive Guide

Milkweed is an essential plant for the survival of the beautiful monarch butterfly, providing both a host for its caterpillars and a source of nectar for the adult butterflies. Learning how to grow milkweed is not only beneficial for these magnificent creatures but also for the overall health of the ecosystem. In this in-depth guide, we will cover everything you need to know about growing milkweed, from planting seeds to caring for established plants.


The Importance of Milkweed for Ecosystem Health

Milkweed is a genus of perennial plants that is essential to many ecosystems, particularly in North America. These plants provide vital resources for a diverse range of species, including insects, birds, and mammals. Here are some reasons why milkweed is so important for the ecosystem:

  1. Monarch butterfly habitat: Milkweed is the only plant on which monarch butterflies lay their eggs, and it is the sole food source for monarch caterpillars. Without milkweed, the monarch butterfly population would decline significantly.
  2. Insect diversity: Milkweed is a critical host plant for many other insect species, including beetles, moths, and bees. These insects rely on milkweed for food, shelter, and reproduction. The flowers of milkweed provide a rich source of nectar for bees, butterflies, and other pollinators.
  3. Bird habitat: Milkweed is an important habitat for many bird species, especially during nesting season. The thick foliage and seed pods provide shelter and food for birds like finches, sparrows, and goldfinches.
  4. Soil conservation: Milkweed has deep roots that help prevent soil erosion and improve soil health. The roots also help to retain moisture in the soil, which is important for plant growth and helps to maintain healthy ecosystems.
  5. Carbon sequestration: Milkweed is an excellent carbon sink, meaning it can absorb and store large amounts of carbon from the atmosphere. This helps to mitigate climate change by reducing the amount of carbon in the atmosphere.

Overall, milkweed plays a crucial role in maintaining healthy ecosystems. It supports a diverse range of species, provides food and habitat for pollinators and other insects, helps to conserve soil and sequester carbon, and is essential for the survival of the monarch butterfly. It is important that we protect and conserve milkweed habitats to maintain a healthy and thriving ecosystem.

Milkweed Varieties

There are numerous milkweed species to choose from when planting milkweed seeds in your garden. Some popular varieties include:

  1. Common milkweed (Asclepias syriaca): This species is native to North America and features pink to purple flowers. It is known for its robust growth and adaptability to various soil types.
  2. Swamp milkweed (Asclepias incarnata): This milkweed species prefers wetter conditions and produces clusters of pink, fragrant flowers. Swamp milkweed is an excellent choice for water gardens or areas with damp soil.
  3. Butterfly weed (Asclepias tuberosa): Butterfly weed is a bright, orange-flowered milkweed species that attracts a wide variety of pollinators. This species is drought-tolerant and thrives in well-draining, sandy soils.

1. How to Grow Milkweed from Seed

Growing milkweed from seed is a straightforward process that begins with a period of cold stratification to ensure successful germination.

1.1 Cold Stratification

Cold stratification is a process that mimics natural winter conditions, preparing the seeds for germination. To stratify milkweed seeds:

  1. Moisten a paper towel or a small amount of peat moss.
  2. Place the seeds on the moistened material and fold it over to cover the seeds.
  3. Seal the folded material inside a plastic bag.
  4. Store the bag in the refrigerator for 30 days.

1.2 Sowing Milkweed Seeds

After the cold stratification period, you can sow your milkweed seeds. Follow these steps:

  1. Choose a well-draining soil mix or create your own by combining equal parts of peat moss, perlite, and compost.
  2. Fill seed-starting trays or small pots with the soil mix.
  3. Plant the stratified milkweed seeds 1/4 inch deep in the soil.
  4. Water the soil gently to ensure it is evenly moist.
  5. Place the trays or pots in a warm, sunny location, such as a south-facing windowsill or under grow lights.
  6. Keep the soil consistently moist until the seeds germinate, which typically takes 10-14 days.

2. How to Plant Milkweed

After your milkweed seedlings have developed at least two sets of true leaves, they are ready to be transplanted into the garden or larger pots.

2.1 How to Plant Milkweed in the Garden

To plant milkweed seedlings in your garden:

  1. Choose a location with full sun, as milkweed requires at least 6-8 hours of sunlight per day.
  2. Prepare the planting area by loosening the soil and removing any weeds.
  3. Dig a hole slightly larger than the root ball of the seedling.
  4. Gently remove the seedling from its container, taking care not to disturb the roots.
  5. Place the seedling in the hole, ensuring that the top of the root ball is level with the soil surface.
  6. Fill in the hole with soil, firming it gently around the seedling.
  7. Water the newly planted milkweed thoroughly.

2.2 How to Plant Milkweed Seeds in Fall

Planting milkweed seeds in the fall allows them to undergo natural cold stratification over the winter. To plant milkweed seeds in the fall:

  1. Choose a suitable location in your garden that receives full sun.
  2. Loosen the soil and remove any weeds from the planting area.
  3. Scatter the milkweed seeds on the soil surface, ensuring they are spaced about 18 inches apart.
  4. Lightly cover the seeds with soil, no more than 1/4 inch deep.
  5. Water the planting area gently to settle the soil around the seeds.

2.3 How to Grow Milkweed in Pots

Growing milkweed in pots is an excellent option for those with limited garden space or who want to move the plants to different locations. To grow milkweed in pots:

  1. Choose a pot that is at least 12 inches in diameter and has drainage holes in the bottom.
  2. Fill the pot with well-draining potting soil or create your own mix, as mentioned earlier.
  3. Plant the milkweed seedlings or seeds in the pot, following the same planting guidelines as for the garden.
  4. Place the pot in a location that receives full sun, ensuring it gets at least 6-8 hours of sunlight per day.
  5. Water the potted milkweed regularly, keeping the soil consistently moist but not waterlogged.

3. Milkweed Care and Maintenance

Proper care and maintenance of your milkweed plants are crucial for their growth and overall health. Here are some essential care tips:

3.1 How Much Sun Does Milkweed Need?

Milkweed requires at least 6-8 hours of direct sunlight per day. While some species can tolerate partial shade, more sun generally results in better growth and flowering. Ensure your milkweed plants receive adequate sunlight by planting them in a sunny location or moving potted milkweed to a sunnier spot if needed.

3.2 Watering Milkweed

Milkweed plants need consistent moisture, particularly during their first year of growth. Water the plants regularly, ensuring the soil remains moist but not waterlogged. Once established, milkweed is relatively drought-tolerant and can withstand occasional dry spells. However, it’s essential to continue monitoring soil moisture and water as needed.

3.3 Fertilizing Milkweed

Milkweed plants do not require heavy fertilization. A balanced, slow-release fertilizer applied once a year in the spring should provide adequate nutrients for healthy growth. Alternatively, you can incorporate compost into the soil around your milkweed plants to supply additional nutrients and improve soil structure.

3.4 Pruning Milkweed

Prune milkweed plants in late fall or early spring to encourage bushier growth and promote flowering. Remove any dead or damaged stems and leaves, and cut back the plant to about 6-8 inches above the ground. This will stimulate new growth and result in a healthier, more attractive plant.

3.5 Pest and Disease Control

Milkweed plants are relatively pest and disease-resistant. However, they can sometimes be affected by aphids, which can be controlled by spraying the plants with a mixture of water and mild dish soap or using insecticidal soap. Milkweed is also susceptible to fungal diseases, such as powdery mildew and rust. To prevent these diseases, avoid overhead watering, ensure proper air circulation around the plants, and remove any infected plant material promptly.

4. Harvesting Milkweed Seeds

Collecting milkweed seeds allows you to propagate more plants and expand your milkweed garden. To harvest milkweed seeds:

  1. Wait until the seed pods have matured and started to split open.
  2. Carefully remove the seed pods from the plant, taking care not to scatter the seeds.
  3. Open the seed pods and remove the seeds, which are attached to silky fluff.
  4. Separate the seeds from the fluff by gently pulling them apart or using a fine-mesh sieve.
  5. Store the seeds in a cool, dry place until you are ready to plant them.

Milkweed Companion Planting

like all plants, milkweed can be susceptible to pests and diseases. Companion planting with milkweed is an effective way to reduce the risks associated with growing this plant, while also promoting healthy growth and maximizing its benefits. In this article, we will discuss some of the best companion plants for milkweed and how to incorporate them into your garden.

Companion Plants for Milkweed

  1. Purple Coneflower (Echinacea) – Purple coneflower is a great companion plant for milkweed because it also attracts pollinators such as bees and butterflies. It is also a hardy plant that can tolerate a range of growing conditions and can help to provide some shade for the milkweed.
  2. Lemon Balm – Another excellent companion plant for milkweed. It attracts a variety of pollinators and can help to deter pests such as aphids and spider mites. Bee balm also has a deep root system, which can help to loosen and aerate the soil, improving water retention and nutrient uptake.
  3. Yarrow – Yarrow is a beautiful and beneficial plant that is often used in natural medicine. It is also a great companion plant for milkweed because it attracts beneficial insects such as ladybugs and lacewings, which can help to control pests such as aphids and spider mites.
  4. Agastache – Agastache, also known as hyssop or hummingbird mint, is another great companion plant for milkweed. It attracts hummingbirds and butterflies, and its fragrant leaves and flowers can help to repel pests such as mosquitoes and flies.

How to Incorporate Companion Plants into Your Garden

There are several ways to incorporate companion plants into your milkweed garden. One way is to plant them in the same bed as the milkweed. For example, you could plant purple coneflower, bee balm, yarrow, or agastache in between the milkweed plants. This allows the companion plants to take advantage of the space and nutrients that are available in between the milkweed plants.

Another way to incorporate companion plants into your garden is to plant them nearby. For example, you could plant purple coneflower or bee balm in a bed next to the milkweed. This allows the companion plants to share the same soil, which can help to reduce pest and disease problems.

It is important to choose companion plants that have similar growing requirements to milkweed. For example, purple coneflower, bee balm, yarrow, and agastache all prefer full sun and well-drained soil. They also prefer warm soil temperatures, so it is best to wait until after the last frost date to plant them.


Learning how to grow milkweed is a rewarding experience that benefits both the environment and your garden. By following these comprehensive guidelines, you can successfully cultivate milkweed plants, support monarch butterflies, and contribute to a healthier ecosystem. Your milkweed garden will also add unique beauty and appeal to your outdoor space, attracting a variety of pollinators and providing a vibrant display of color throughout the season.


  1. I live in Detroit and yesterday found hundreds of milkweed seeds sheltering under a bush in a schoolyard. I’m assuming they were there in the winter time.
    So I think I should try starting them inside, we may get a frost tonight – our safe to plant date is either May 15/May 31.
    My apartment is very small. I’ll only have room for2-3 little pots but can I plant them outside after May 31?

    • If those are seeds that survived outside through the winter, then they should be good to try and germinate—milkweed seeds need to be cold-treated otherwise.

      You can start the milkweed seeds indoors anytime now. A couple of weeks after the last frost date, you can either sow the seeds or transplant the seedlings outside. I hope this helps!

  2. I have just (August 8/21) collected several seed pods. If I wish to cold treat them outdoors, how should I keep them before planting in the fall?

    • Hi Michael,

      You’ll want to let them dry out until you’re ready to plant the seeds. The easiest way is to put the milkweed pods in a paper bag and close up the end. Then store them in a dry place.

  3. I also live in Michigan. What is the best kind of soil for milkweed – sandy, mulched, loose, clay??? What about pH and nutrients?

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