10 Types of Milkweed in Louisiana (AND One to Avoid!)
“What types of milkweed should I plant in my garden?”
This may seem like a crazy question if you’re just getting started with native gardening. Why would you want to plant a weed?!
But milkweed isn’t a weed at all. Instead, it’s a flowering plant that attracts butterflies (think Monarchs), native bees, and other pollinating insects, which is an excellent thing!
This article will give you information about common types of milkweed in your area and which ones will be best for your garden. And, keep reading to the end to learn about a kind of milkweed you want to avoid!
10 Types of Milkweed in Louisiana:
#1. Whorled Milkweed
- Asclepias verticillata
Growing Information:
- USDA Hardiness Zone: 3-10
- Life Cycle: Perennial
- Approximate Mature Size: 1 to 3 feet
- Bloom Time: May to September
Whorled Milkweed is the most broadly distributed milkweed species in Louisiana.
This unique perennial is sometimes overlooked by gardeners who want to plant milkweed. Compared to other varieties, it has a narrow stem and spiky leaves arranged in a spiral pattern. When not in bloom, it easily blends in among grasses.
It blooms from May to September, forming flat-topped clusters of small greenish-white flowers on the end of each stem. The flowers attract various insects, including bees, wasps, butterflies, skippers, beetles, and flies.
Whorled Milkweed is still a welcome host plant for Monarch Butterfly caterpillars despite its unique appearance. Since this species is one of the last milkweeds to die back in the fall, it’s a great late-season host for Monarchs preparing to migrate south!
This delicate-looking wildflower can easily grow from seed, but it may not flower the first year. It can be grown in full sun or partial shade. Whorled Milkweed thrives in various habitats, including fields, pastures, roadsides, dry prairies, dry slopes, woodlands, and meadows. Unfortunately, it’s highly poisonous to livestock and is considered a nuisance weed in agricultural areas.
It grows best in dry soil of various types, including sandy, rocky, and clay soils. It can also be grown in moist, average garden soil. Keep in mind that it is an aggressive spreader by seeds and underground rhizomes, so you may not want to choose this milkweed if you have a limited area for gardening.
#2. Butterfly Weed
- Asclepias tuberosa
Growing Information:
- USDA Hardiness Zone: 3-9
- Life Cycle: Perennial
- Approximate Mature Size: 2 to 3 feet
- Bloom Time: May to September
Butterfly Weed is a showy member of the milkweed family. Sometimes called Orange Milkweed, this perennial wildflower features large flat-topped clusters of tiny flowers that grow 2 to 5 inches across. The blooms are brilliant orange or yellow.
Interestingly, its dark green leaves and stems don’t produce the same milky sap as other species of milkweed in Louisiana.
Butterfly Weed is an excellent choice for gardens and or wildflower meadows. The beautiful flowers are fragrant and are ideal for cut flower arrangements. They also attract native bees, butterflies, and honeybees to your garden. Butterfly Weed is also a host plant for Monarch, Gray Hairstreak, and Queen butterfly caterpillars.
This native flower is a great low-maintenance choice for the home gardener. Butterfly Weed’s deep taproots mean you’ll never need to water it once it’s established. In addition, this plant is highly drought tolerant and thrives in full sun. Butterfly Weed also does fine without any fertilization but grows best in rocky or sandy soil.
Unlike Common Milkweed, this species doesn’t transplant well and should be started from seed.
RELATED: 20 Rabbit Resistant Plants to grow in Louisiana!
#3. White Milkweed
- Asclepias variegata
Growing Information:
- USDA Hardiness Zone: 3-9
- Life Cycle: Perennial
- Approximate Mature Size: Up to 3 feet
- Bloom Time: May to July
White Milkweed has distinctive, spherical clusters of about 30 small, white flowers. At first, the flower buds are green but turn white before blossoming. There are tinges of purple at the base, which is why this perennial is also called Redring Milkweed. The flowers are full of nectar and have a sweet fragrance that attracts bees, wasps, butterflies, and ants.
Unlike many milkweed species that prefer full sun, White Milkweed typically grows in open woodland and along woodland edges. However, in the garden, it thrives in areas with partial shade and creates a snowball effect with its gorgeous round clusters of white flowers.
Sadly, this milkweed species is endangered in parts of its range, but it can be cultivated from seed. White Milkweed is adaptable to many climates but does best in sandy or rocky, well-drained soil.
White Milkweed doesn’t typically form large colonies in a natural setting, unlike other milkweed species. Combined with its tendency to grow in partial shade, this scarcity means it isn’t a critical host plant for Monarch butterfly caterpillars. However, they will occasionally use it in a garden setting. Other insects like bees, tussock caterpillars, and local butterflies will also be attracted to White Milkweed.
#4. Green Comet Milkweed
- Asclepias viridiflora
Growing Information:
- USDA Hardiness Zone: 3-10
- Life Cycle: Perennial
- Approximate Mature Size: 1.5 to 2 feet
- Bloom Time: June to September
Green Comet Milkweed flower clusters form in the pocket created by the upper leaves. They’re made up of 20 to 80 small, pale green flowers. Interestingly, the yellowish-green leaves of this species vary in shape depending upon their habitat. Plants from moist sites tend to have rounder leaves, while plants from dry sites have long, narrow leaves.
In the wild, this species is often found on shaded roadsides, savannas, and prairies with moist to dry soil. In the garden, you can grow Green Comet Milkweed from seeds. It grows best in light to moderate shade but will tolerate full sun. Medium-dry to dry soil is best. Green Comet Milkweed doesn’t need rich soil and will tolerate sandy or rocky soil with low organic matter.
This species is a good choice for low-maintenance gardens as its long taproot allows it to tolerate drought well. Unlike many other milkweeds, this species is easy to prevent from spreading. It doesn’t form the large colonies typical to other milkweeds, so it’s an excellent option for smaller gardens!
The Green Comet Milkweed’s copious nectar and sweet fragrance attract many pollinators, including honeybees, native bees, and butterflies. It’s also a host plant for Monarch Butterflies, though it can be more challenging for monarchs to find because of its scarcity and preference for partial shade.
#5. Green Milkweed
- Asclepias viridis
Growing Information:
- USDA Hardiness Zone: 4-9
- Life Cycle: Perennial
- Approximate Mature Size: 10 inches to 2 feet
- Bloom Time: April to September
In the wild, Green Milkweed can be found growing on prairies, roadsides, clearings, ditches, and disturbed roadsides. It thrives in dry areas with limestone soils and grows in large clusters.
Typically, one Green Milkweed stem will produce a single cluster of small flowers. The flowers are white or yellow-green with a purple tinge. Larger plants may have multiple clusters on one stem.
Green Milkweed can be easily grown from seed in home gardens. It is tolerant of light shade but does best in areas that receive full sun. Its large taproot gives it excellent drought resistance. Sow it in areas with well-drained sandy or rocky soil for best results.
This is one of the first species of milkweed in Louisiana to die back in late summer.
This makes it less appealing to Monarchs and other moths and butterflies as a host plant than other species. However, it is still sometimes used, and resident butterflies and other pollinators frequent its flowers for nectar.
#6. Aquatic Milkweed
- Asclepias perennis
Growing Information:
- USDA Hardiness Zone: 6-11
- Life Cycle: Perennial
- Approximate Mature Size: 1.5 to 2 feet
- Bloom Time: May to September
Aquatic Milkweed can only grow in areas where the soil is continuously wet! Therefore, it can be found in floodplains, waterway margins, marshes, cypress swamps, ditches, and wetlands in the wild. This perennial is easily identified by the large pink spot at the tip of the unopened flowers.
Aquatic Milkweed produces umbels with about 25 flowers. The flowers are typically white or light pink.
Although it has fairly specific requirements, Aquatic Milkweed can be grown in home gardens in the right climate. It needs full sunlight and continuously moist soil. It’s an excellent choice for planting around water features and wet areas.
This species is a host for Monarch, Queen, and Soldier Butterfly caterpillars which eat the plant’s leaves. Bees, butterflies, and other pollinators are also attracted to the plant’s fragrant flowers.
#7. Clasping Milkweed
- Asclepias amplexicaulis
Clasping Milkweed is a fairly rare species. It is named for its characteristic leaves, which wrap around or clasp the stem.
Clasping Milkweed has thick waxy leaves, which are an adaptation to their habitat. They hold extra moisture, allowing the plant to survive severe droughts. Clasping Milkweed grows in prairies, open savannas, meadows, and other natural areas with few or widely spaced trees.
Unlike most other milkweed species in Louisiana, Clasping Milkweed features just a single rounded cluster of about 25 large, fragrant flowers. The individual flowers are usually pinkish or purplish with some green or cream in them with petals that are bent backward.
Clasping Milkweed has very specific habitat needs. This perennial grows best in full sunlight in areas with dry, sandy, or gravelly soil and little competition from other perennials.
#8. Tall Green Milkweed
- Asclepias hirtella
Also known as Prairie Milkweed, this single-stemmed perennial grows up to 3 feet (1 m) tall. Like other milkweeds, the leaves and stems have white, latex-like sap.
Tall Green Milkweed has flower clusters that look a bit like green pom-poms. Each plant typically produces clusters of 30 to 100 tiny, greenish-white flowers, more than most other milkweed species. The flowers form along the length of the stem.
You’ll likely find this milkweed species in Louisiana growing in prairies and other open habitats like rocky glades, roadsides, sandy wetland edges, pastures, and abandoned fields. Tall Green Milkweed thrives in areas with full sun and well-drained soil.
#9. Fewflower Milkweed
- Asclepias lanceolata
Fewflower Milkweed grows to a surprising 3 to 5 feet tall and features stunning clusters of fiery orange flowers. These tall, narrow plants are tough to spot and almost invisible in their native landscape until they bloom!
However, Fewflower Milkweed still features the tell-tale white sap of the milkweed genus. Like other milkweeds in Louisiana, it’s an essential source of food for Monarch, Queen, and Soldier caterpillars that are specially adapted to feed on milkweeds’ toxic sap.
This delicate perennial grows in swamps, wet pinelands, coastal prairies, ditches, and fresh and brackish marshes. It does well in areas that are seasonally inundated with water.
#10. Longleaf Milkweed
- Asclepias longifolia
Longleaf Milkweed is a slender, unbranched perennial. As the name suggests, the leaves are often much longer than other milkweed species. The leaves also help set this species apart as each plant has a large number of leaves, so many that they’re not easily countable at a glance.
Usually, Longleaf Milkweed blooms in the spring, but occasionally, you’ll see it blooming in summer or early fall. The flowers form in clusters at the top of the plant’s stem. The individual flowers are greenish with white corollas tinged with purple.
Longleaf Milkweed grows in Louisiana in bogs, moist to wet flatwoods, and prairies. It prefers full sun but will tolerate partial shade. Unfortunately, Longleaf Milkweed is rare or extinct in parts of its former range.
Tropical Milkweed
- Asclepias curassavica
Growing Information:
- USDA Hardiness Zone: 8-11
- Life Cycle: Perennial
- Approximate Mature Size: 3 to 4 feet
- Bloom Time: March to November in temperate climates, year-round in tropical climates.
This non-native milkweed plant has become popular in recent years because of its flowers’ bright red coloring and how easy it is to plant and maintain.
Unfortunately, Tropical Milkweed planted in Louisiana may do more harm than good.
It carries a parasite of Monarch Butterflies called Ophryocystis elektroscirrha, or OE, which can cause defects in the wings of Monarchs. Since it doesn’t die back and can bloom late, the plant itself may also confuse Monarchs by signaling a breeding season when it’s time to migrate.
To ensure you’re planting milkweed that will help your local ecosystem and attract native pollinators, always choose a native species!
Marketers of Tropical Milkweed seeds will use the names Mexican Milkweed, Bloodflower, Mexican Butterfly Weed, Mexican Orange Milkweed, and Semi-Tropical Milkweed. Steer clear of all of these!
Are you looking for more information on milkweed in Louisiana?
Check out this guide!
Do you have milkweed in your garden?
What’s your favorite thing about this plant? Leave a comment below!
