Milkweed plants are perhaps most well-known as the host plants for monarch butterfly larvae. Each year, the butterflies visit milkweed plants and lay their eggs on the leaves so the caterpillars will have the food they need readily available when they hatch. Milkweeds are also a host plant for swallowtail butterflies, and their flowers serve as a source of nectar for many kinds of adult butterflies, bees, and other pollinators.
I have been so encouraged by the number of monarch butterflies I have seen visiting the milkweed plants in my garden this year. For several years, it seemed as if I would only see one or two per season, but this year, I saw them almost daily for a few weeks, and I have found plenty of eggs on the milkweed leaves.
The flowers of milkweeds remind me of Hoya flowers. Both species have waxy-looking, fragrant blooms and are members of the Apocynaceae plant family, which is sometimes called the milkweed family or dogbane family.
There are several species / varieties of milkweed that are commonly available, including common milkweed, narrow-leaf milkweed, swamp milkweed, showy milkweed, and pleurisy root (sometimes called butterfly weed), among others. Flowers of different species and varieties can be pink, cream, white, yellow, orange, or other colors. Some can grow several feet tall while others tend to have a lower growth habit.
It is often recommended to grow the species / variety that grows wild in your own region, but you can plant a selection of varieties that appeal to you as well.
Growing Milkweed from Seed
To grow milkweed from seed, you will want to sow your seeds in trays or pots a few weeks before your last frost date. You can also direct sow them after the ground has warmed up in spring. Some species have smaller seeds than others. As a general rule, you want to sow the seeds about as deep as the size of the seed is. For a variety with very small seeds, you might only sow the seeds 1/8” deep, but for varieties with larger seeds, you might need to plant them ¼” to ½” deep. Water the seeds in, then keep the soil moist until the seeds germinate.
Once your seedlings have a few sets of true leaves and are several inches tall, you can transplant the seedlings into the garden. Most of the varieties can be planted about 18” apart, but the ones that grow quite large need more space. Check your seed packet for specific spacing instructions for the variety you are planting.
Caring for Milkweed Plants
Milkweed plants are perennials down to USDA growing zone 3, which means that if your garden is in a zone 3 or warmer, the plants will come back year after year for you. They can spread via seed and underground rhizomes, so you may want to contain them in raised beds or large containers to help keep them in one space.
Once established, the plants are quite low maintenance. They get at least one feeding with a balanced fertilizer in spring when I feed the rest of my garden, but I have seen them growing wild in places that do not receive the same treatment and they do quite well in those conditions too.
In good, nourished soil, they will grow taller and more lush than they will in poor, rocky, or damaged soil, but the plants seem to be quite resilient regardless of where they are grown.
Note: Please do not spray your milkweeds with pesticides. These can be harmful to the butterflies and their larvae. Milkweeds can attract aphids (you can use this to advantage by using them as a trap plant to keep the aphids away from other things in your garden). If this happens to your plants and you wish to intervene, just spray the aphids off with water from the hose or brush them off the plants. Do not treat them with chemicals, or you will risk the health of the very pollinators you wish to help by planting the milkweeds. If you leave the aphids on some of the plants, ladybugs will likely lay their eggs nearby and your garden’s natural ecosystem will likely balance them out in time.
Caution: Milkweed sap is poisonous and can sometimes cause a skin rash if you get it on your skin while you’re working in the garden. Be careful handling plants and seedlings and wear gloves if you have sensitive skin. Do not ingest the plant.
About the Author
Hi there, I’m Erin! I am the main instructor here at Floranella. I am a clinical herbalist, aromatherapist, artisan distiller and organic gardener based in the Pacific Northwest. Here at Floranella, I teach people how to work with plants safely and effectively from the garden to the apothecary. Thanks for being here! I’m glad you stopped by.
