Plant Profile : Common Milkweed (Asclepias syriaca)

The stunning and beautiful native plant that has a very sweet scent that pollinators love, and provides food for insects and wildlife. You will learn all about common milkweed, the insects that use it as food, the type of care that this species of Milkweed needs, and the secret that this plant hides within it's leaves, flower buds, flowers, and stem. After learning more about this plant you will have more respect for it.

A lot of people think Common Milkweed is just an ordinary weed, and that this plant isn't important to have. Common Milkweed is not a weed at all but instead this plant is a native wildflower with beautiful blooms, and it is beneficial towards a wide variety of insects and wildlife. It is one of the well known native plants in North America including Canada and The United States due to it being commonly seen everywhere out in the wild especially along roadsides, fields, forests, and trails. This is a great native plant to add to your property because it does lots of things for biodiversity and supports lots of wildlife. You will find out why Common Milkweed is so important, and so much more as you read through this article.

Common Name: Common Milkweed

Scientific Name: Asclepias syriaca

Older Names: Butterfly Flower, Silkweed, Swallow - wort, and Virginia Silkweed.

Plant Family: The Dogbane Family

Genus: Asclepias

Native Range: Canada and The United States

Description: Common Milkweed is a tall species of Milkweed. This type of milkweed has a long stem, big leaves, and has big and round flower clusters. The scent that the flower clusters give off on this plant is a very beautiful fragrance.

Flower Colour: Pink to purplish

Foliage Colour: Grey - Green

Height: 2 - 4 feet tall

* Common Milkweed can grow up to 5 or 6 feet tall if it is really happy in the location in which it was planted in.

Width: 24 - 30 inches wide

Plant Characteristics

Foliage: Common Milkweed has thick light green leaves that are 3 to 12 inches in length. The leaves are flat in a elongated rectangle shape, the underside is greyish green and covered in little hairs, has reddish veins, and are rounded at both ends where they have a pointed tip. When a leaf is picked off of the plant or is crushed up the milky sap that the plant produces appears from the the leaf veins, and the stem of the leaf.

Stem: The stem on a common milkweed plant is green in colour, and looks similar to a bamboo stalk but thinner than bamboo. It is straight and upright, has no branches, hollow, and is covered in short hairs that resembles peach fuzz. When a piece of the stem is broken off the milky sap that common milkweed produces appears right in the location of where the piece of it was broken off.

Flowers: The flower buds on common milkweed look like little balls or beads, and are light green or a dark green in colour. When the flower buds are almost ready to burst open, they change to a greenish pink in colour. A day or two before the flower clusters begin to bloom the flower buds become more pinkish white in colour. In a small degree the flower clusters hang loosely on the plant and are shaped like a sphere. The clusters of flowers have as many as 100 flowers, but usually there are 30 + plus flowers per cluster.

Each stalk that bears an individual flower on a common milkweed plant are 1 1/2 inches (4 cm) long. The petals of each flower are a third of an inch long which isn't really big. The hoods of the flowers on this plant holds nectar, and the horns of the flowers on the plant are located inside of the hoods which are really close to the pollen that the flowers produce. The hoods and horns of the flowers are usually white or purple in colour. The flowers on a common milkweed plant are usually a light pink or a pale pink in colour. The flowers on common milkweed plants have the same aroma as Lilacs, and when you are nearby a patch of common milkweed you can smell them from a good distance.

Fruit: After the flower clusters on common milkweed have finished blooming they produce pretty large seed pods that are full of seeds. The seed pods are very bumpy that have lots of spots which feel rough when touched. Each seed pod on a common milkweed plant is about 5 inches long in length containing many flat brown seeds.

When the seeds are developing inside the seed pods on a common milkweed plant they're soft, brittle, and white in colour which occurs during the time of when the seeds are not viable where they're not ready to be harvested. The seeds are light brown to a dark brown in colour when they're viable and ready to be harvested for the following year. Each seed that is inside the seed pods are covered in a papery wrapping and are attached by a fuzzy paracute at the tip of them.

The seeds in the seed pods are arranged in layers like the scales on a butterfly's wings. When the seed pods are ready to be harvested they will go from a green colour to a dark brownish grey colour, and they become dried up and not soft anymore. When this occurs the seed pods will burst open on their own, and the seeds will begin to not be attached to one another, and each seed will be carried away by the wind to a new location for where a new common milkweed plant will grow.

Type Of Plant: Herbaceous flowering plant

Life Cycle: Perennial

Light Exposure: Full Sun

Soil Type: Dry and well drained

Soil pH: Acidic and neutral

Bloom Time: June through August

Hardiness Zones: In the United States the hardiness zones that Common Milkweed grows best in are 3 through 9. In Canada the hardiness zones that this plant grows best in are 3 through 7.

Host Plant For: Monarch Butterfly, Milkweed Tussock Moth, and Red Milkweed Beetle.

Common Milkweed Plant Care

Light: Common Milkweed prefers to be planted in a location that gets full sunlight throughout the day. This species of milkweed grows best in an open space where there is six to eight hours of sunlight during the day.

Soil: This plant prefers to be planted in dry to medium average and well drained soil. Common Milkweed tolerates dry, infertile soil, and rocky conditions. This species of Milkweed thrives in soil with a pH range of 4.8 to 7.2.

Water: Common Milkweed does not need to be watered except when the plant has encountered dry conditions where there has not be any rain. Water far down and mostly at the base of the plant including the soil, Make sure when you water you give this species of milkweed one to two inches of water. Once this plant has been watered well wait until the top of the soil is dry before watering common milkweed again. Overwatering common milkweed can result in a plant fugus that is very deadly towards this plant.

Temperature & Humidity: Common Milkweed can tolerate a wide range of temperatures and humidity. This species of Milkweed will not do well in extreme heat that lasts for a long period of time.

Fertilizer: For common milkweed plants there is no need to fertilize them, and this plant can tolerate poor soils.

Common Milkweed Plant Tips:

1. When planting common milkweed choose a location that has well drained soil and has full sun exposure during the day. There is no need for enriching the soil of where this plant has been planted.

2. Plant common milkweed about 18 inches a part, and it will quickly fill in the space that is between plants due to the spreading of their rhizome roots.

3. Common Milkweed may not be best for formal perennial borders because of it's tendency to spread aggressively. This species of Milkweed is better suited for naturalized areas such as open fields, meadows, butterfly gardens, raised garden beds, and raised garden boxes.

4. Collect some of the common milkweed seed pods if you don't want the plants to spread too much. Don't collect all of the seed pods because you should leave some seed pods on the plants in order for some new plants to grow in the garden.

Attracts: Bumble Bees, Great Black Wasps, Golden Digger Wasps, Leafcutter Bees, Monarch Butterflies, Mason Bees, Milkweed Tussock Moths, Fireflies, Red Milkweed Beetles, Small Milkweed Bugs, Big Milkweed Bugs, Mining Bees, Swallowtail Butterflies, Hoverflies, small sized Butterflies, and other Beneficial Insects.

Wildlife Benefits :

The flowers on common milkweed support a wide diversity of insects including Carpenter Bees, Bumble Bees, Leafcutter Bees, Butterflies, Moths, Hummingbirds, and even Hoverflies.

This plant supports the life cycle of a Monarch Butterfly, the life cycle of a Milkweed Tussock Moth, and the life cycle of Milkweed Beetles. The flower buds, flowers, foliage, and seed pods provide food for Monarch caterpillars, Milkweed Tussock Moth caterpillars, and Milkweed Beetles.

During the fall and winter this species of milkweed provides food for many of our songbirds and small wildlife. Many our birds and beetles feed on the seeds of this milkweed as a food source in the fall and through the winter months. The left over seed pods that are dried up and opened provide shelter for many of our beneficial beetles and insects, and the hollow stems of common milkweed provide shelter for many of our native bee species that are nesting bees. The stem and plant fibers from common milkweed plants provide nesting material for several of our songbirds including Baltimore Orioles, and Golden Finches.