Milkweed – it’s a generic term used to describe what can actually many different species.
Milkweeds are important for butterflies, with the highest profile species benefiting from the plants being the increasingly endangered Monarch Butterflies. It’s the most well known of all the milkweed butterflies who require these plants for laying their eggs. Their larvae then feed on the milkweed – therefore these plants are essential for Monarchs and other Nymphalidae – Danainae species of butterfly!
If you’re planting a new garden, or just adding to an existing one, including native milkweeds is one of the best things you can do for Monarch and some other butterfly species. And there are plenty of milkweed plants to choose from. As a bonus, they all have spectacular flowers and add so much life and color to a garden of any size and style.
Before we continue though – an important matter to address regarding Milkweed and why we need to really pay attention to the types we’re planting.
In 2015, researchers found that well intentioned gardeners and butterfly enthusiasts who had planted milkweed specifically for Monarch’s had, instead of helping them, been harming them simply by planting the wrong species of milkweed! This led to a higher risk of a parasite infecting the butterflies and of their migration to Mexico being in jeopardy.
Asclepias curassavica (Tropical Milkweed), the most popular and common milkweed available in the USA is what people were planting, simply because that was the species they could find in plant nurseries and unless one has a specific interest in botany, a milkweed to most people. Understandably, these gardeners believed they were doing all the right things for the Monarchs.
However, this was sadly not the case because this particular species of milkweed isn’t adapted well to some parts of the country and instead of normally dying back in winter like it does in the tropical heat where it’s originally from, the Monarchs end up staying at the ever lasting source of milkweed year round and missing the migration altogether.
To add to the bad news, a particular protozoan parasite is hosted on these milkweeds which affects the newly hatched larva who go on to live shorter lives on average compared with healthy Monarchs – it is thought that Monarchs infected with the parasite won’t be physically able to complete the migration at all.
So many butterfly experts are now advising that people who have already planted tropical milkweed to replace it with a native milkweed species – even though the native species are not as easily available as tropical milkweed, it is well worth the effort if you want to help and not hinder Monarch butterflies.
What is native to you when it comes to Milkweeds will of course largely depend on where you live, but many species are widespread and naturally range throughout a wide belt of states throughout the country. The challenge of course is to find somewhere to buy native milkweed seeds and plants.
By adding milkweed plants to your garden you are directly contributing to the conservation of Monarch butterflies – and with any luck, you’ll be rewarded by their presence in your garden!