Prairie Milkweed
asclepias sullivantii
Also known as: ["Green Milkweed","Sullivant's Milkweed"]
Overview
A native perennial herbaceous plant known for its clusters of pale pink to greenish-white flowers and milky sap.
Benefits & Perks
["wildlife attractant (bees, butterflies, birds)","drought tolerant","shade tolerant"]
Botanical Classification
| Phylum: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Gentianales |
| Family: | Apocynaceae |
| Genus: | Asclepias |
| Botanical Name: | Asclepias sullivantii |
Plant Characteristics
Basic Information
- Category: Flowers
- Suitable Location: garden bed in full sun, tolerates prairie conditions
- Suitable For:
- Is Weed: No
- Allergenicity: low
Environmental Needs
- Climate: {"temperatureRange":"–30 to 40°C"}
- Hardiness: {"zones":"3–9"}
- Misting: rarely required, only if ambient humidity is very low
- Drainage: Fast-draining to prevent root rot.
- Soil Type: Well-draining, loamy soil with added organic matter; cactus or succulent mix can work well.
Maintenance Level
- Maintenance Level: moderate
- Toughness Level: high
- Pruning Frequency: Annually in late winter or early spring before new growth begins.
- Pruning Intensity: Moderate; remove up to one-third of the plant if overgrown.
Care Details
Ideal Sunlight Coverage:
Full sun (6–8 hours of direct sunlight daily); tolerates partial shade but may produce fewer flowers.
Sunlight Tolerance Tips:
Acclimate plants gradually to full sun if moved from shade; protect from intense midday sun in hot climates; ensure adequate airflow to prevent fungal issues.
Care Requirements
Care Difficulty
moderatemoderate
Sunlight
full sun
Rotate plant for even growth; use shade cloth in extreme heat; avoid placing in drafty areas.
Watering
every 7–10 days during active growth, reduce in winter
Water thoroughly until runoff, ensure good drainage, and avoid overwatering to prevent root rot.
Soil
well-drained, loamy soil with moderate fertility
pH: Slightly acidic to neutral (pH 6.0–7.0).
Use a mix with good aeration; avoid heavy clay soils; ensure pots have drainage holes.
Temperature
Prefers 65–85°F (18–29°C); tolerates temperatures down to 20°F (-6°C) when dormant.
Protect from frost; water early in the day; avoid sudden temperature fluctuations.
Fertilizing
every 4–6 weeks during spring and summer
Fertilize in spring and summer only; do not over-fertilize to prevent root burn; flush soil occasionally to prevent salt buildup.
Propagation
Methods
Stem cuttings or seed; stem cuttings are faster and more reliable.
Step-by-Step Propagation Guide
- Take a 4–6 inch cutting.
- Remove lower leaves.
- Dip in rooting hormone.
- Plant in medium.
- Keep moist and warm.
Best Time: Spring or early summer when the plant is actively growing.
Environment
Warm, humid environment with indirect light; maintain consistent moisture.
Medium
Well-draining potting mix with perlite or sand; can also root in water initially.
Hormone
Rooting hormone is recommended to improve success rates.
Timeline
Roots may appear in 2–4 weeks; new growth in 6–8 weeks.
Tools Needed
Pruning shears, rooting hormone, small pots, well-draining medium.
Quick Tips
Use healthy, non-flowering stems; keep cuttings out of direct sun; maintain humidity with a plastic bag or dome.
Pruning & Repotting
Pruning Guide
Method
Cut stems just above a leaf node or bud; thin out crowded areas to improve airflow.
Pruning Plan
Prune to maintain shape, encourage bushier growth, and remove dead or diseased stems.
Tools
Pruning shears, sterilizing solution, gloves.
Checklist
Sterilize tools; prune before new growth; remove dead/diseased stems; shape as desired.
Repotting Guide
Best Season
Early spring before active growth begins.
Pot Size
Increase pot size by 2–3 inches in diameter; ensure good drainage holes.
Method
Remove plant gently; trim roots if necessary; place in a new pot with fresh soil; water lightly.
Suggestions
Repot every 2–3 years or when roots fill the container; beneficial for growth and health.
Checklist
Choose appropriate pot size; use fresh soil mix; handle roots carefully; water after repotting.
Advanced Care Tips
Watering Mastery
Watering Checklist
Check soil moisture before watering; water deeply; ensure drainage; adjust frequency by season.
How to Apply Water Properly
Water at the base of the plant, focusing on the root zone, until water penetrates the root ball; ensure excess water drains away to prevent waterlogging.
Watering Schedule Tips
Water deeply once a week during the growing season; reduce frequency in winter to every 2–3 weeks, allowing soil to dry between waterings.
Soil Improvement
Add perlite or sand for drainage; incorporate compost for fertility; ensure soil is not compacted.
Temperature Stress Management
Signs of Temperature Issues
Wilting, yellowing leaves, stunted growth, or bud drop in extreme heat; leaf drop or dieback in prolonged cold.
Cold Stress
Slows growth, may cause leaf drop, and can lead to root damage if soil freezes.
Solution: Mulch heavily around the base; move potted plants to a sheltered location; avoid overwatering in cold weather.
Hot Stress
Leaves may scorch, wilt, or drop; flowering may be reduced.
Solution: Provide afternoon shade; water deeply in the morning; increase humidity around the plant.
Fertilizing Guide
Fertilizing Checklist
Use diluted fertilizer; apply during active growth; avoid winter feeding; flush soil periodically.
Fertilizing Method
Use a balanced, water-soluble fertilizer diluted to half strength every 4–6 weeks during the growing season; avoid fertilizing in winter.
Common Problems & Solutions
Toxicity Warning
Cats
ToxicCats are highly sensitive to the cardiac glycosides in Asclepias sullivantii, which can cause severe cardiac and neurological effects. Even small amounts can be dangerous.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Dogs
ToxicThe cardiac glycosides in Asclepias sullivantii are highly toxic to dogs, affecting cardiac and neuromuscular systems. Ingestion can lead to severe gastrointestinal and cardiovascular distress.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Humans
ToxicAsclepias sullivantii contains cardiac glycosides, which can disrupt heart function and electrolyte balance when ingested. These compounds interfere with sodium-potassium pumps in cells, leading to severe physiological effects.
⚠️ Symptoms:
🌿 Toxic Parts:
⚡ Toxic If:
if eaten
Frequently Asked Questions
Q: Is Prairie Milkweed toxic to pets?
A: Yes, it is mildly toxic to dogs and cats if ingested.
Q: Does Prairie Milkweed attract pollinators?
A: Yes, it is highly attractive to bees, butterflies, and other pollinators.
Q: How much sunlight does Prairie Milkweed need?
A: It thrives in full sun to partial shade.
Quick Reference
| Family: | Apocynaceae |
| Care: | moderate |
| Light: | full sun |
| Water: | every 7–10 days during activ |
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