Grow Milkweed, Save Monarch Butterflies: A Step-by-Step Guide

Where to Plant Milkweed

Hardiness: Most plants thrive in hardiness zones 3-10.

Choose a sunny location: Most species prefer full sun and will not grow well in shaded areas. Choose a location that receives at least 6 hours of direct sunlight daily.

Well-drained soil: Most Milkweed plants prefer well-drained soil. They can tolerate a range of soil types but do not grow well in compacted or waterlogged soil. However, there are some species, such as swamp milkweed (Asclepias incarnata) and prairie milkweed (Asclepias sullivantii), which do well in saturated conditions.

Site: Milkweed can be planted in the ground or containers.

When to Plant Milkweed

Seed: If you plant milkweed from seed, sow your seeds directly into the soil in the fall. Alternatively, you can start your seeds indoors 4-8 weeks before the average date of the last frost.

Plant: If you purchase a potted plant, plant it directly into the garden in spring after the danger of frost has passed.

How to Plant Milkweed

Prepare the soil: Prepare the planting site by removing any weeds or grass and loosening the soil to a depth of at least 6 inches (15 cm). Add compost or other organic matter to the soil to improve drainage and fertility.

Plant the seeds or seedlings:

• Plant your seeds directly into the soil in the fall. Alternatively, you can start your seeds indoors 4-8 weeks before the average date of the last frost.
• Use plastic flats or seedling trays.
• Fill them 3/4 with potting soil, and scatter the seeds on the soil surface 1/2 in. (1 cm) apart.
• Cover with 1/4 in. (0.5 cm) of soil mix.
• Water thoroughly and place them in a sunny window or directly under the grow lights.
• Most seeds will germinate in 7-10 days if the flats are maintained at 75˚F (24˚C). After the seeds have germinated and are 3-6 in. tall, they are ready to be transplanted into your garden.
• Plant your seedlings 6-24 in. apart (15-60 cm), depending on the species.

Plant in groups: Planting several milkweed plants together can help attract more monarch butterflies and other pollinators. Grouping plants also makes it easier to care for and maintain them.

Milkweed Care

Watering: Water newly planted milkweed regularly, about once a week, until they become established. Once established, milkweed is drought-tolerant and does not require regular watering except during prolonged dry periods.

Fertilization: Milkweeds generally do not require regular fertilization, but they can benefit from a balanced, all-purpose fertilizer in early spring before new growth begins.

Mulching: Mulch around the base of the plants with organic mulch, such as leaves or bark, to retain moisture, suppress weeds, and regulate soil temperature.

Pruning: Prune in early spring to remove dead or damaged growth and control the plant’s size. Cutting back milkweeds in the fall can also help prevent the spread of diseases.

Overwintering: You can leave milkweeds standing in the fall to provide a habitat for overwintering insects or cut them back to the ground and cover with a layer of mulch to protect the roots from freezing.

Replanting: Milkweed is a perennial plant, but some species may need to be replanted every few years to maintain healthy growth.

Overall, milkweeds are relatively low-maintenance plants that can thrive with minimal care. By providing the right growing conditions and monitoring for pests and diseases, you can enjoy healthy and vibrant milkweed plants that provide important habitat for monarch butterflies and other pollinators.

Spicebush Swallowtails on Milkweed

Pests and Diseases

Milkweed plants can be susceptible to a few different pests and diseases, harming the plant’s health and reducing its ability to provide habitat for monarch butterflies and other pollinators. Here are some common pests and diseases to watch out for:

Aphids: Aphids are small, soft-bodied insects that can be found feeding on the leaves and stems of plants. They can cause the plant to become stunted and discolored and can also transmit viral diseases. Aphids can be controlled with insecticidal soap or by introducing natural predators, such as ladybugs or lacewings.

Milkweed bugs: Milkweed bugs are orange and black insects that feed on the seeds. They are not harmful to the plant but can be unsightly and can reduce seed production. Handpicking or vacuuming the bugs can help control their population.

Fungal diseases: Milkweeds can be susceptible to fungal diseases, such as powdery mildew, which can cause white, powdery growth on the leaves and stems. Fungal diseases can be prevented by providing good air circulation, avoiding overhead watering, and removing infected plant material.

Viral diseases: Some viral diseases, such as the milkweed mosaic virus, can cause yellow mottling on the leaves and stunting of the plant. There is no cure for viral diseases, so infected plants should be removed and destroyed to prevent the spread of the disease.

How to Prevent Milkweed from Spreading

Milkweeds can be vigorous growers and can potentially spread beyond their intended area. Here are some tips to help control their spreading:

Regularly remove milkweed pods: Milkweed seeds are carried by the wind and can easily spread beyond their intended area. To prevent spreading, remove seed pods before they have a chance to mature and release their seeds. If you want to collect seeds for propagation, do so carefully and responsibly.

Plant milkweed in containers: If you’re concerned about milkweed spreading in your garden, plant it in containers. This will help prevent the plant from spreading beyond its intended area.

Choose non-invasive species: Some species, such as common milkweed (Asclepias syriaca), can be invasive in some areas. Choose non-invasive species, such as swamp milkweed (Asclepias incarnata) or butterfly milkweed (Asclepias tuberosa), to reduce the risk of spreading.

How to Propagate

Seeds: Milkweed seeds can be sown directly in the ground in the fall or early spring or started indoors in late winter or early spring. Sow the seeds about 1/4 inch deep in well-draining soil, and keep the soil moist until the seeds germinate. Once the seedlings have several leaves, they can be transplanted into the garden.

Cuttings: Milkweed can be propagated from stem cuttings taken in late fall or early spring. Cut a 4- to 6-inch section (10-15 cm) of stem and remove the lower leaves. Dip the cut end of the stem in rooting hormone and plant it in a container filled with moist potting soil. Keep the soil moist and the container in a warm, bright location until roots develop, then transplant the cutting into the garden.

Division: Plants can be divided in the spring or fall by carefully digging up the plant and separating it into smaller sections. Each section should have several shoots and a portion of the root system. Replant the sections in well-draining soil, and keep the soil moist until the plants become established.

Is Milkweed Toxic?

Milkweeds are toxic to humans and animals and can cause a range of symptoms if ingested. The plant contains a milky sap that is bitter and contains cardenolides, which are toxic compounds that can cause gastrointestinal distress, nausea, vomiting, and other symptoms.

While milkweed is toxic, it is also an important plant for monarch butterflies and other pollinators. The toxicity is actually what makes it an effective host plant for monarch butterfly larvae, which are able to sequester the cardenolides in their bodies as a defense against predators.

It’s important to handle these plants with care, especially when planting or handling them. Here are some tips for handling the plant safely:

• Wear gloves: When handling the plant, wear gloves to protect your skin from the milky sap.
• Wash your hands: After handling the plants, wash your hands thoroughly with soap and water to remove any sap or residue.
• Don’t ingest the plant: Milkweed should not be ingested by humans or animals, as it can cause a range of symptoms.
• Keep away from children and pets: Milkweed should be kept out of reach of children and pets, who may be tempted to taste or play with the plant.

Frequently Asked Questions

Is planting milkweed a good idea?

Planting milkweed is a great idea as it supports the monarch butterfly population and contributes to the health of the ecosystem.

Where is the best place to plant milkweed?

Milkweed is a hardy and adaptable plant that can grow in a variety of conditions. It prefers full sun, well-draining soil, and moderate moisture. It can be planted in a garden bed, container, or even a meadow or wildflower garden. The best place to plant milkweed will depend on the specific species and your local climate and soil conditions

What is so special about a milkweed?

Milkweed is a crucial plant for many species, especially monarch butterflies. It is the only plant on which monarch butterflies lay their eggs, and it is also a primary food source for their caterpillars. It is also known for its medicinal properties and has been used in traditional medicine for centuries. Finally, this is an important plant for the environment, as it supports a diverse range of insects and other wildlife.

What’s the other name for milkweed?

Milkweed is also known as Asclepias.

What does milkweed look like?

Milkweed plants are recognized for their distinctive features: they have sturdy, upright stems with broad or lanceolate leaves that are often opposite or whorled. The flowers, which bloom in clusters, are intricate and come in shades of pink, orange, and white, depending on the species. Each flower consists of a central crown surrounded by petals that curve backward. Following flowering, the plant produces seed pods that open to release seeds attached to silky hairs, allowing them to be carried by the wind.

Is milkweed poisonous?

Yes, milkweed is poisonous. It contains cardiac glycosides, particularly cardenolides, which can be toxic to both humans and animals if ingested in significant quantities. These compounds are a defense mechanism against herbivores, making the plant bitter and potentially harmful.

Got questions about milkweed? We have the answers!