Photo: John BarklaCC BY 4.0via iNaturalistresized / cropped
Blue Speargrass Plant Care
Aciphylla glaucescens W.R.B.Oliv.
Updated · Sources · How we source care data
With its spiky, silver-blue leaves resembling a giant sea urchin, this plant originates from the mountains of New Zealand. Plant collectors are drawn to Aciphylla glaucescens for its unique and striking appearance, adding a touch of exotic flair to their collections.
Every 7–14 days
Full sun to partial shade
50–75°F
40–70%
At a glance
How do you care for Blue Speargrass?
Water Blue Speargrass every 7–14 days, letting the top layer of soil dry out between waterings, and give it full sun to partial shade. It prefers temperatures of 50–75°F (10–24°C) and 40–70% humidity. Fertilize it every 6 months during the growing season.
Where Is the Blue Speargrass Native To?
What Is the Blue Speargrass?
Blue Speargrass (Aciphylla glaucescens) belongs to the Apiaceae family within the Aciphylla genus. Blue Speargrass is native to New Zealand. Blue Speargrass is also known as Glaucous Speargrass.
Blue Speargrass displays a clumping perennial growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Blue Speargrass produces small white or greenish flowers in dense clusters.
Leaf size: approximately 12 inches.
How Often Should You Water a Blue Speargrass?
Aciphylla glaucescens requires watering every 7–14 days. Allow the top layer of soil to dry between waterings to prevent root rot. Reduce watering frequency during winter when growth slows.
Watering Frequency
Every 7–14 days
Let soil partially dry between waterings
What Light Does the Blue Speargrass Need?
Blue Speargrass thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Blue Speargrass Prefer?
Aciphylla glaucescens grows best at temperatures of 50–75°F. Blue Speargrass prefers humidity levels of 40–70%.
Temperature
50–75°F
Humidity
40–70%
What Soil Mix Works Best for a Blue Speargrass?
Well-draining sandy soil with good organic matter content. Good drainage is essential for Blue Speargrass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Blue Speargrass?
Feed Blue Speargrass every 6 months during the growing season (spring and summer) with a balanced fertilizer diluted to the strength on the label.
Pause feeding in autumn and winter, when growth slows, and never fertilize dry soil — water first.
Fertilizing
Every 6 months
During the growing season
The PlantoScan app can remind you when to water and when to fertilize each plant.
How Do You Repot a Blue Speargrass?
Repot every 2-3 years in early spring. Choose a pot one size larger than the current container, and ensure it has drainage holes to allow excess water to escape.
How Do You Propagate a Blue Speargrass?
Blue Speargrass can be propagated through seeds, division of offsets.
Is the Blue Speargrass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Blue Speargrass, so we can't confirm whether it is safe for cats and dogs. Keep pets from chewing it as a precaution.
This is a general caution, not veterinary or medical advice. If your pet ate a plant, contact your vet or animal poison control.
See all plants toxic to cats and plants toxic to dogs.
What Pests and Diseases Affect the Blue Speargrass?
Blue Speargrass is susceptible to aphids, caterpillars, slugs. Inspect the foliage regularly, especially along leaf undersides and stems. Treat infestations promptly with insecticidal soap or neem oil to prevent spread.
Yellow leaves, brown tips or drooping? See common plant problems and how to fix them.
What USDA Hardiness Zone Does the Blue Speargrass Need?
Blue Speargrass grows outdoors in USDA Zone 7b – 9b. It survives winters down to planting zone 7b. Blue Speargrass is native to New Zealand.
Hardiness Zone
Zone 7b – 9b
Keep exploring plants
Blue Speargrass is one of many species covered in the complete plant care and identification guide, which groups plants by genus, attribute, and popularity.
It belongs to the Aciphylla genus — compare its care with other Aciphylla species on PlantoScan.
Aciphylla is part of the Apiaceae plant family — browse all Apiaceae genera and species.
Blue Speargrass thrives in bright light and direct sun — see other bright-light plants.
Related Plant Care Guides
Closely related plants with similar care requirements:
Sources
- Scientific name & taxonomy: Aciphylla glaucescens W.R.B.Oliv., family Apiaceae (first published in Trans. Roy. Soc. New Zealand 84: 13 (1956)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Blue Speargrass, so we can't confirm whether it is safe for cats and dogs. Checked against the ASPCA plant list; any other toxicity note on this page comes from PlantoScan's plant database.
- Photo: John Barkla, CC BY 4.0, iNaturalist — original.
- Hardiness zone: USDA Zone 7b – 9b, estimated from the plant's typical growing conditions.
- Care values(watering, light, temperature, humidity, soil, fertilizing): PlantoScan's plant database, filtered by automatic plausibility checks — values that fail them are hidden. How we source and check plant data.
Spotted a mistake? Email info@upvision.media with the page link — we check and correct reported errors.
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