Asclepias verticillata — a medium houseplant, prefers full sun light
SPECIMEN · FROM THE LIBRARY
Asclepias verticillata

Asclepias Verticillata

Updated · 185 observations
ON THIS PLANT

Asclepias verticillata, the whorled milkweed, eastern whorled milkweed, or horsetail milkweed, is a species of milkweed native to most of eastern North America and parts of western Canada and the United States.

A note from PlantMom

Whorled Milkweed resists disease well and is generally not highly susceptible. However, it can be affected by pests and diseases present in its environment. Such infections are usually not severe. In terms of care, the plant requires moderate maintenance. It should be pruned regularly to maintain a good appearance and healthy growth. Fertilizing can also help encourage flowering. Whorled Milkweed is suitable for people with outdoor spaces like a garden or patio and does not demand much gardening experience. It may require more attention when grown indoors.

— PlantMom
CARE GUIDE

How to keep Asclepias Verticillata.

Light

Whorled Milkweed does best in areas that receive steady sunlight for most of the day. Although it can survive in spots with somewhat less light, consistently reduced sun exposure can interfere with its proper development. Both excessive and inadequate light can negatively affect the plant’s overall health.

Water

Whorled Milkweed thrives in well-drained soils and benefits from consistent moisture, mirroring the conditions of its natural prairie habitat. Once established, it becomes moderately tolerant to drought. For optimal growth, it is recommended to water it weekly, typically outdoors where natural rainfall can support its water needs during the growing season.

Temperature

Whorled Milkweed comes from environments with temperatures between 32 to 95 °F (0 to 35 ℃). Its growth and survival are optimal within this range, though it can tolerate minor fluctuations. Seasonal adjustments to accommodate the plant's temperature needs may be necessary in harsh winters or extremely hot summers.

Fertilizer

The best time to fertilize Whorled Milkweed is in early spring, as it comes out of dormancy and starts active growth. Fertilizing supplies essential nutrients that support healthy development. While Whorled Milkweed needs relatively little fertilizer, applying it once a year can improve its chances of survival and encourage fuller, longer-lasting flowers.

Pruning

To keep whorled milkweed healthy, regularly remove any infected plants and wilting leaves. If you live in a tropical climate, prune the branches in early spring to encourage better growth. Due to the plant's high toxicity, always wear gloves when handling it, keep it out of reach of children, and avoid ingestion.

CHARACTERISTICS

Botanical profile.

Plant Type
Herb
Life Cycle
Perennial
Genus
Asclepias
Family
Apocynaceae
Hardiness Zone
3-10
Mature Height
30 cm to 76 cm
Mature Spread
30 cm to 61 cm
Leaf Color
Green
Leaf Type
Deciduous
Flower Color
White
Flower Size
2.54 cm
Bloom Time
Early summer, Mid summer
Planting Time
Spring, Summer
Harvest Time
Mid summer
ALSO KNOWN AS

Other names.

en Whorled milkweed en Horsetail milkweed en Eastern whorled milkweed
FREQUENTLY ASKED

Reader questions.

How should I water my Whorled Milkweed?

To water the Whorled Milkweed plant effectively

Why should I put fertilizer on my Whorled Milkweed plant?

Fertilization is important for the Whorled Milkweed and other plants because it provides essential nutrients. Whorled Milkweed has relatively low fertilization needs and can sometimes survive without it. However, annual fertilization can greatly benefit the plant by keeping it alive and enhancing the quality and longevity of its flowers. Those who want their Whorled Milkweed to thrive should consider regular fertilization.

What are the sunlight requirements for Whorled Milkweed?

Whorled Milkweed requires full sun exposure to thrive effectively, necessitating more than 6 hours of sunlight daily, though it can also manage in partial sun conditions, which account for about 3-6 hours of sunlight each day. It's crucial to observe the movement of sunlight through your garden to pick locations offering an optimal mix of light and shade, guaranteeing the plant's well-being. This careful selection ensures that the plant receives the unremitting light essential for its growth for the majority of the day, avoiding the adverse effects of too much or too little sunlight on its health.

What is the preferred temperature range for Whorled Milkweed to grow?

Whorled Milkweed, also known as Asclepias verticillata, thrives in environments experiencing temperatures ranging from 32 to 95 °F (0 to 35 °C). This range is optimal for its growth and survival, but it can tolerate mild fluctuations. Even though it possesses strong cold resistance, care should be taken to adjust for seasonal variations to meet the plant's temperature needs in extreme weather conditions.

What should I do if I give my Whorled Milkweed too much or too little water?

Overwatering is a common issue that can negatively affect the health of your Whorled Milkweed. It can cause wilting and yellowing of the stems and leaves, and can even lead to diseases like root rot, mold, and mildew which can be lethal to your plant. On the other hand, underwatering is less common as the Whorled Milkweed has good drought tolerance. However, when underwatering does occur, the leaves can become brittle and brown. It's important to recognize the signs of overwatering early on to prevent irreparable damage. Reduce your watering schedule and assess the soil quality if you notice signs of overwatering. If your Whorled Milkweed is not receiving enough water, simply water more regularly until the signs improve.

When should I fertilize my Whorled Milkweed?

The best time to fertilize a Whorled Milkweed is in late winter or early spring. This is when the plant is coming out of dormancy and starting to grow actively. Fertilizing at this time helps promote healthy growth and gives the plant a good start for the season. While it's generally best to fertilize in the early spring, it is also okay to fertilize in the fall. However, it's not recommended to feed the plant during the summer or winter seasons.

How does artificial lighting help indoor Whorled Milkweed plants?

For indoor Whorled Milkweed plants, natural sunlight may not always be sufficient, especially in winter or less sunny spaces. In these cases, artificial lights, such as LED lights customized to provide specific wavelengths, become crucial. They promote faster, healthier growth by compensating for the lack of natural light. Full sun plants require 30-50W/sq ft of artificial light, partial sun plants need 20-30W/sq ft, and full shade plants need 10-20W/sq ft. The artificial light source should be placed 12-36 inches above the plant to mimic natural sunlight and kept on for 8-12 hours per day, depending on the plant species' natural daylight needs.

How to protect Whorled Milkweed during extremely cold winters?

To protect Whorled Milkweed during exceptionally cold winters where temperatures are expected to drop below -35°C, it’s advisable to employ cold protection methods. This can include covering the plant with insulating materials like soil or straw. An additional tip is to water the plant abundantly before the first freeze of the autumn season, ensuring the soil remains moist when it enters a frozen state. This strategy helps prevent drought and water scarcity for the plant during the harsh winter and early spring.

How frequently should I give water to my Whorled Milkweed plant?

If your Whorled Milkweed is in a pot, the best way to determine if it needs water is to check the soil by sticking your finger into it. If the top two to three inches of soil feel dry, then it is time to water it. If you have your Whorled Milkweed planted in the ground, you can use a similar method to test the soil. Once again, if the top few inches of soil have dried out, it is time to water the plant. During the spring and early fall, you will typically need to water this plant once every week using this method. However, in extremely hot weather, you may need to increase the frequency to about twice or more per week. However, it is worth mentioning that mature and well-established Whorled Milkweed plants have a remarkable ability to withstand drought.

When is it not a good idea to add fertilizer to my Whorled Milkweed?

Only fertilize your Whorled Milkweed during late winter and early spring. This plant has low fertilization needs, so one feeding per year is sufficient. Fertilizing in spring, summer, and fall can easily cause overfertilization and complications. However, if you didn't fertilize in spring, it is okay to feed the plant in the fall. Additionally, refrain from fertilizing during most of the growing season and winter. The plant is dormant in winter and does not grow, so fertilization is not recommended during that time.

What are the symptoms of insufficient or excessive sunlight on Whorled Milkweed?

Symptoms of insufficient sunlight in Whorled Milkweed include small new leaves, leggy or sparse growth, faster leaf drop, slower or halted new growth, lighter-colored new leaves, leading to a general weakening of the plant. Excessive sunlight, on the other hand, can cause chlorosis, sunscald, leaf curling, wilting, and leaf scorching, negatively impacting the plant's ability to photosynthesize and its overall health. These symptoms highlight the importance of providing Whorled Milkweed with the right amount of sunlight, whether grown indoors or outdoors.

What should be done if Whorled Milkweed experiences temperatures below its cold tolerance?

Whorled Milkweed can tolerate cold down to -30°C, but when temperatures fall below -35°C, its health might not show immediate decline, but sprouting in spring could be adversely affected. If Whorled Milkweed fails to sprout properly in spring due to extreme cold, it is recommended to remove the parts of the plant that have not sprouted to promote new growth and to maintain plant health.

PLATES
Asclepias verticillata leaf
PLATE 01 · leaf
Asclepias verticillata leaf
PLATE 02 · leaf
Asclepias verticillata flower
PLATE 03 · flower
Asclepias verticillata flower
PLATE 04 · flower
Asclepias verticillata fruit
PLATE 05 · fruit
Asclepias verticillata fruit
PLATE 06 · fruit
ALSO IN THE LIBRARY

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