With a few simple steps — and the right plants — you can turn your garden, patio, or balcony into a haven where monarchs flourish naturally.
Why Swan Plants Matter
Monarch butterflies are New Zealand’s best-known butterfly, yet their numbers are under threat from predators like social wasps, pesticides, and climate change. In New Zealand, monarch caterpillars rely on milkweed — most famously the swan plant (Gomphocarpus physocarpus). It’s the only plant family they can eat, making it an essential hero in any monarch-friendly garden.
Plant More Than You Think You’ll Need
Monarch caterpillars can strip a swan plant bare almost overnight.
- Grow from seed: It’s easy, rewarding, and you know your plants are chemical-free. Older, second-year plants grow bigger and cope better with hungry caterpillars.
- Buy butterfly-approved plants: At Oderings, our swan plants are pesticide-free and safe for caterpillars.
- Encourage bushier growth: Pinch out the growing tips when plants reach about 15–20 cm to double the leaves.
- Focus on foliage: Removing flowers helps your plant put energy into leaves, not seeds.
Feed Adult Butterflies, Too
When your caterpillars transform into butterflies, they’ll need nectar-rich flowers. Plant echinacea, zinnias, cosmos, buddleia, coreopsis, daisies and more. These flowers also attract bees and other pollinators, adding even more life to your garden. Plant in clusters or blocks of colour (at least three of each) so butterflies easily spot them.
Keep Your Garden Butterfly-Safe
- Avoid using pesticides, sprays or even plug-in insect repellents.
- If you need to move caterpillars, place new plants beside the old ones or lay cut stems at the base; let caterpillars crawl naturally.
- Wear gloves when pruning swan plants, as they’re poisonous to people and pets.
Create a Monarch Habitat
- Add a butterfly house or sheltered spot to protect them from bad weather.
- Make a simple nectar bowl: mix one part sugar with four parts hot water, cool, and place outdoors.
- Provide shallow water dishes for butterflies to drink from.
How to Grow Swan Plants from Seed
- Sow in spring into seed-raising mix, about 5 mm deep.
- Keep warm and moist; seeds germinate in 1–3 weeks.
- Transplant when seedlings are 8–10 cm tall, spacing about 30–40 cm apart in full sun.
- Pinch out tips to help plants bush out and produce more leaves.
With just a few plants, you can enjoy the magic of monarchs fluttering through your garden each summer. Visit us in store or online at Oderings for butterfly-safe swan plants and nectar favourites — and help keep this special butterfly thriving for years to come.
Need help getting started? Check out our range of butterfly-attracting plants or visit The Daily Gardener and the Monarch Butterfly NZ Trust for more tips on designing your butterfly haven.
