Attract monarch butterflies to your garden with swan plants

Need to know: swan plants and monarch butterflies

If you’re planning to plant swan plants, keep these basics in mind:

• Swan plant leaves are a key food source for monarch caterpillars during the larval stage.
• Plant swan plants in a sunny, sheltered spot with good drainage.
• In frosty areas, swan plants may not survive.
• Avoid insecticides and foliar sprays on leaves, because monarch eggs and caterpillars are easily harmed.
• Wear gloves when handling swan plants, as the sap can irritate skin and may be harmful if swallowed.

Why swan plants attract monarch butterflies

Swan plants are popular for one simple reason: monarch butterflies lay eggs on them, and once the eggs hatch, the caterpillars feed on the leaves. With swan plants in your garden, you may get to see multiple stages of the monarch life cycle, from eggs and caterpillars through to chrysalis and butterfly.

If you’re gardening with kids, this is a great chance to talk about how insects grow and change over time. It also helps to plant more than one swan plant, so there’s more leaf growth available if caterpillars arrive in numbers.

Growing and caring for swan plants

You can grow swan plants from nursery plants or from seed. If you’re starting from seed, transplant seedlings into the garden once they’re established and more than 10cm high.

For best results:

• Choose a protected, sunny position with well-draining soil.
• Water to help plants settle in, especially during dry spells.
• In areas that get frost, swan plants may not survive cold nights, so many gardeners treat them like annuals.

When plants are small, they can be eaten back quickly by hungry caterpillars. If you’d like the plant to put on more size first, you may want to protect young plants until they’re more established.

Short on garden space? Swan plants can also grow well in suitably sized pots on patios or balconies, as long as they get plenty of sun and drainage.

Protect monarch eggs and caterpillars from sprays

Monarch eggs and caterpillars are highly sensitive to insecticides, so it’s best to avoid spraying swan plants. If you’re buying plants, swan plants purchased from our nurseries are not sprayed with dangerous or residual insecticides that will harm monarchs.

It’s also worth avoiding foliar fertilisers on the leaves, as these can affect eggs and caterpillars too. Instead, feed the plant by applying liquid fertiliser to the soil or potting mix every few weeks during the growing period.

Gardening safely with swan plants

Swan plants can release a white sap when damaged. This sap can cause allergic reactions in some people and may be harmful if swallowed, so take extra care around young children.

To garden safely:

• Wear gloves when handling swan plants or pruning damaged stems.
• Avoid touching your face and wash hands after handling the plant.
• If sap gets in your eyes, rinse with water and seek medical advice if irritation continues.

Get your garden ready for monarchs

Add a few swan plants to a sunny spot in your garden (or a pot on the patio), and you’ll be set up to enjoy the monarch lifecycle through the warmer months.

Frequently asked questions

Do swan plants need full sun?
Swan plants grow best in a sunny, sheltered position. Sun helps them grow stronger and produce more leaves for caterpillars.

When can I transplant swan plant seedlings into the garden?
If you’ve grown swan plants from seed, transplant them once they’re established and more than 10cm high.

Will swan plants survive frost?
In frosty areas, swan plants often don’t survive cold nights. Many gardeners treat them as annuals and replant when conditions warm up.

Can I grow swan plants in pots?
Yes. Choose a suitably sized pot with good drainage, use a quality potting mix, and place it somewhere sunny like a patio or balcony.

Should I spray swan plants for pests?
It’s best to avoid insecticides and leaf sprays on swan plants, because monarch eggs and caterpillars can be easily harmed.