Native Plants in Bloom: Rose Milkweed
There are a number of native plants that are both beautiful and provide important resources for a diverse group of insects in the local ecosystem, but few come close to matching Rose Milkweed in those categories. Also commonly called Swamp Milkweed because of its preference for moist soils, it can adapt to medium soil moisture and works best in full sun or part sun locations. In comparison to Common Milkweed, it has much narrower leaves and spreads only by seed (Common spreads by underground rhizomes and seed). I find them to be elegant-looking plants, perfect for gardens large and small alike.
Rose Milkweed is not just a host plant for Monarch caterpillars, it's one of the most preferred of any of the milkweeds for egg-laying Monarch butterflies. Its flowers draw a stunningly diverse array of pollinators to the garden, from tiny Yellow-faced bees to large Bumble bees, butterflies, moths, ants and more. It's not uncommon for us to see female Monarchs lay eggs and nectar on them. While Common Milkweed tends to bloom in June and July in our garden, Rose Milkweed starts around the same time and goes straight through August. Another feature that I love: its flowers smell like candy! It's an absolutely wonderful scent. No wonder the insects go bonkers for it!
We typically see these plants hit four or five feet in height if they're doing well and maybe three feet if they're in a pot or less optimal soil and moisture conditions. And that's one really great feature of these plants, they work well in larger pots (2 gallons or larger) as long as you make sure to water them on sunny days. Even if you site them in-ground in the garden, you want to make sure they have adequate moisture, watering if necessary during dry spells. Drought tolerant? Not so much. But worth making the extra effort to have them? In my opinion - absolutely.
Along with Wild Bergamot, Common Milkweed, Late Boneset, New England Aster, and various goldenrods, Rose Milkweed helps form the core of our garden. Early on in our garden's life, we tried transplanting them, but found that they are really easy to spread by broadcasting the seed, having good enough germination rates for our needs. This has led to a number of surprises as far as where these plants have managed to grow, including right alongside our gravel path, which seems pretty far removed from the normal site recommendations for them.
In the fall, when Rose Milkweed seed pods open, their seeds have silky parachutes called "floss" that help them float away from the parent plant on the wind. And if you're interested in harvesting them, the floss is easy to separate from the seeds (unlike some other species that are a pain to clean!). The dry seed pods are also nice for winter interest.
This species has so much to offer humans and non-humans alike: beauty, adaptability, nectar rewards for insects, food for Monarch caterpillars, and lovely scented flowers. Without it, our garden would be a less interesting and also less dynamic place.
It's a plant that screams summer for me, since its bloom season almost perfectly matches the season. Like asters and goldenrods in the fall, milkweeds like this one have a very strong seasonal association.
If you have a chance to plant it, we can't recommend it enough for your sunny garden or balcony.
-Andrew