If you plant them, they will come. Milkweed, that is. And butterflies.
Milkweed and monarch butterflies have a vital connection because monarch butterflies only lay their eggs on milkweed leaves. The eggs hatch into caterpillars which eat the leaves for food.
Milkweed is the Monarch’s sole host plant and serves as a source of nectar for many other species of butterflies and pollinating insects. The University of Florida cites an estimated 80-90% decline in the monarch butterfly population in recent decades, raising concerns about the fate of these magnificent insects.
Milkweed belongs to the genus Asclepias, derived from the Greek god of medicine and healing – Asklepios. Of the 130 species of Asclepias, 11 varieties grow wild in our region. Three of the most common are milkweed (Asclepias tuberosa), common milkweed (Asclepias syriaca), and swamp milkweed (Asclepiiasincarnate).
Common milkweed is the best-known milkweed and thrives in full sun to partial shade in medium to well-drained soil. It spreads by underground rhizomes and grows 4 to 6 feet tall. It blooms from June to August and has large clusters of fragrant pink spherical flowers. The large leaves, covered with short woolly hairs on the undersides, rest on a single stem.
Butterfly grass grows in full sun in dry to medium soil. It is drought tolerant and reaches 1 to 3 feet tall. Bright orange flowers bloom in late summer. When the stems are broken, the sap is not milky like in other varieties. Butterfly grass grows in a more clump-like formation.
Swamp milkweed does best in moist soil with full sun to partial shade and reaches heights of 4 to 5 feet. The 3 to 6 inch leaves are lance-shaped and the mauve to pink to purple flowers bloom throughout the summer.
Milkweed seeds are easy to grow. If you have the seeds in fall or early winter, they can be sprinkled around the garden. Burying the seeds in the fall can reduce germination because they need light to germinate. Just drop the seeds on the ground and press them gently with your hand. The seeds will germinate and start growing in the spring.
Seedlings can be transplanted when they are a few centimeters tall. Keep new plants watered until well established.
There are several options for planting milkweed seeds in the spring. However, the seeds must go through a stratification process to germinate. Cold stratification is the process of subjecting seeds to both cold and moist conditions to break dormancy. You can do this in your refrigerator using one of the following options:
1. Place seeds in a damp paper towel inside a sealed bag and refrigerate for 30 days. To avoid damage, use a low-traffic area of your refrigerator, such as the crisper drawer or tape the bottom of a shelf. After that, sow directly in the garden covered with a quarter inch of soil. Thin at 12 inches.
2. Put the seeds in a moist seed starting mix in peat pots and cover with a quarter inch of soil. Protect with transparent film and refrigerate for 30 days. After that, move to a warm place to germinate. Keep moist.
After germination, remove the cover and provide natural or artificial light. If the plants get tall, they need more light.
At about 3 inches, transplant peat pots into the garden. Make sure the top edge is covered with soil. Otherwise, it can wick moisture away from the roots. Plant in full sun after danger of frost and water until established.
3. Combine the seeds with an equal or greater amount of moist sand, perlite, vermiculite or other sterile media. It should not flow when squeezed. All seeds should be in contact with the moist medium during the cold stratification process and should be stored in a container or plastic bag in the refrigerator for three to four weeks.
Then sow directly in the garden and cover with a quarter inch of soil. Or fill pots or trays with light, well-drained soil and add seeds. Cover with a quarter inch of soil and keep moist. Place it in a warm, sunny location or under grow lights.
After danger of frost, and when the plants have four true leaves, they are ready for planting out.
If you’re concerned about the fate of monarch butterflies, plant milkweed this year. It’s so much fun to watch your new plants grow, but it’s even more fun and amazing to see the monarch butterflies you’ve attracted to your milkweed. It is also very gratifying to know that you have contributed to the breeding and development of this species for years to come.
Milkweed is a perennial (comes back every year) and may or may not flower the first season.
The Ohio State University Extension offers common milkweed seed packets. Call or stop by for details. A donation of $2 is suggested for a packet of approximately 65 to 70 seeds. The extension is located at 490 S. Broad St. in Canfield. For details, visit http://go.osu.edu/milkweedseeds.
For more information on Monarch Help, visit http://go.osu.edu/monarchhelp.
For more information on growing milkweed, visit http://go.osu.edu/growmilkweed.
Dolak is a volunteer master gardener at Ohio State University Mahoning County Extension.