How to Grow Blunt Leafed Greenhood
Wikimedia Commons
Blunt Leafed Greenhood
Pterostylis obtusa
flowerPterostylis obtusa is a small terrestrial orchid native to southeastern Australia, characterized by its distinctive hooded flowers with a blunt, rounded dorsal sepal. This deciduous orchid produces flowers in spring and is prized by orchid enthusiasts for its unique morphology and intricate pollination mechanisms. It thrives in cool, moist woodland conditions and is best suited to temperate climates.
When should you plant Blunt Leafed Greenhood in your zone?
Get a personalized planting timeline — when to start seeds, transplant, and harvest — based on your USDA zone and local frost dates. Free to start.
Example Blunt Leafed Greenhood timeline · Pittsburgh, PA (Zone 6b)
-
Plant Blunt Leafed Greenhood
Around Apr 17Near Pittsburgh's average last spring frost.
-
Tend & protect
Late spring–summerWatering, feeding, and pest-watch reminders.
-
First Blunt Leafed Greenhood blooms
Around Aug 15≈ 120 days after planting
Sample dates for Pittsburgh, PA. Sign up to get exact Blunt Leafed Greenhood dates for your own zip code.
Growing Conditions
Soil
Growing Zones
Find your zone →Thrives in zones 8-9; requires cool winters and can be grown outdoors in temperate regions or in controlled greenhouse conditions
Sign up free to see if Blunt Leafed Greenhood grows in your zone — and get a personalized planting timeline.
Get my Blunt Leafed Greenhood timeline →Growth Stages
Dormancy
June-August (2-3 months)Plant exists as a subterranean tuber with minimal visible growth; no above-ground foliage present
Keep soil slightly dry to avoid tuber rot; maintain cool temperatures (50-55°F); reduce watering significantly
Early Growth
August-September (3-4 weeks)Shoot emerges from tuber; first leaves appear as small green shoots breaking through soil surface
Begin increasing watering as growth emerges; maintain cool, humid conditions; provide good air circulation to prevent fungal issues
Vegetative Development
September-November (6-8 weeks)Plant develops 2-4 slender, lance-shaped leaves arranged in a rosette; leaves are light green and relatively narrow
Maintain consistent moisture without waterlogging; ensure filtered light; monitor for pests and fungal infections; maintain humidity at 60-70%
Flowering
October-December (3-6 weeks)Inflorescence emerges with 1-3 distinctive hooded flowers; flowers are typically olive-green with reddish or purplish markings; dorsal sepal is notably blunt and rounded
Continue consistent watering; maintain cool temperatures (55-65°F); provide good air circulation around flowers; do not mist flowers directly; flowers are ephemeral and may last only days
Seed Set and Senescence
December-May (5-6 months)Flowers fade and drop; if pollinated, seed capsules develop; foliage begins to yellow and decline; plant prepares for dormancy
Reduce watering gradually as foliage yellows; allow soil to dry progressively; stop fertilizing; do not remove foliage until completely brown and withered
Companion Planting
Plan your garden →Plant with:
Avoid planting near:
Common Pests
-
Improve air circulation; reduce watering frequency; use yellow sticky traps; ensure media dries slightly between waterings
-
Increase humidity; spray with water to dislodge; use miticides if severe; maintain good air circulation
-
and
Remove by hand; create barriers with copper tape or diatomaceous earth; use mollusk baits if necessary
-
Ensure excellent drainage; reduce watering; improve air circulation; remove affected tissues; repot in fresh media if severe
Uses
Insect Pollination
WildlifePterostylis obtusa employs a sophisticated pollination strategy involving male insects (primarily sawflies) that are attracted by the flower's shape and pheromone-mimicking chemistry. The hooded structure traps insects, forcing them through the flower's interior where they encounter pollen, demonstrating complex plant-insect coevolution. [source]
Horticulture and Orchid Collection
CraftPterostylis obtusa is highly valued by specialized orchid collectors and botanical gardens for its unique morphology, ecological significance, and challenge in cultivation. Growing this orchid requires developing advanced plant care skills and contributes to the conservation of terrestrial orchid species. [source]
Traditional Aboriginal Knowledge
MedicinalPterostylis species have been used in traditional Aboriginal Australian medicine; while scientific validation is limited, tubers of related Pterostylis species were consumed and may have had nutritional or minor medicinal applications. [source]
Shade Garden Interest
HouseholdThis orchid adds unique aesthetic and botanical interest to cool, shaded garden spaces and woodland displays. Its delicate hooded flowers and seasonal growth pattern create visual intrigue for discerning gardeners seeking native Australian flora. [source]
This is not medical advice. LizPlants is not a medical resource. Always consult a qualified healthcare professional before using plants medicinally.
Harvest Tips
This orchid is not harvested for consumption or cutting. For seed collection, allow pollinated flowers to set seed capsules naturally; harvest capsules once they turn brown and papery (typically 4-6 months after pollination) and allow seeds to disperse in controlled conditions. For propagation, remove and pot fresh tubers in autumn.
Fun Facts
- 🌱 Pterostylis obtusa exhibits remarkable insect mimicry, with its flowers chemically and visually deceiving male sawflies into attempting mating, a pollination strategy called pseudopheromone attraction or 'sexual deception.'
- 🌱 This orchid is deciduous, existing as an underground tuber during summer dormancy, an adaptation to Australian woodland conditions with seasonal moisture availability.
- 🌱 The genus Pterostylis comprises over 100 species endemic to Australia and New Zealand, with P. obtusa being one of the most horticultural-interesting species for temperate cultivation.
Gardening Terms
New to gardening? Learn about terms used in this guide:
Join 30,000 gardeners planning their gardens with LizPlants.
Get your personalized Blunt Leafed Greenhood planting timeline
Tell us your zip code and we'll calculate exactly when to start Blunt Leafed Greenhood seeds, transplant seedlings, and harvest — based on your USDA zone and local frost dates. Includes calendar reminders and printable task lists. Free to start.
Get my Blunt Leafed Greenhood timeline →