Guinea Grass Plant Care
Megathyrsus maximus (Jacq.) B.K.Simon & S.W.L.Jacobs
Updated · Sources · How we source care data
Megathyrsus maximus, known as Guinea grass and green panic grass, is a large perennial bunch grass that is native to Africa and Yemen. It has been introduced in the tropics around the world.
Every 7–14 days
Full sun
65–85°F
40–70%
At a glance
How do you care for Guinea Grass?
Water Guinea Grass every 7–14 days, letting the top layer of soil dry out between waterings, and give it full sun. It prefers temperatures of 65–85°F (18–29°C) and 40–70% humidity. Fertilize it every 8 months during the growing season.
Where Is the Guinea Grass Native To?
- Algeria
- Angola
- Benin
- Botswana
- Burkina Faso
- Burundi
- Cameroon
- Cape Verde
- Central African Republic
- Chad
- Côte d'Ivoire
- Djibouti
- DR Congo
- Egypt
- Equatorial Guinea
- Eritrea
- Eswatini
- Ethiopia
- Gabon
- Ghana
- Guinea
- Guinea-Bissau
- Kenya
- Lesotho
- Liberia
- Libya
- Madagascar
- Malawi
- Mali
- Mauritania
- Morocco
- Mozambique
- Namibia
- Niger
- Nigeria
- Republic of the Congo
- Rwanda
- Sao Tome and Principe
- Senegal
- Sierra Leone
- Somalia
- South Africa
- South Sudan
- Sudan
- Tanzania
- The Gambia
- Togo
- Tunisia
- Uganda
- Yemen
- Zambia
- Zimbabwe
What Is the Guinea Grass?
Guinea Grass (Megathyrsus maximus) belongs to the Poaceae family within the Megathyrsus genus. Guinea Grass is native to Africa and Yemen. Guinea Grass is also known as Green Panic Grass, African Grass, Colonial Grass.
Guinea Grass displays a tall, bunch grass growth habit, reaching up to 6 ft tall with a spread of approximately 2 ft. Guinea Grass produces inconspicuous flowers in dense spikelets.
Leaf size: approximately 12 inches.
How Often Should You Water a Guinea Grass?
Megathyrsus maximus 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 Guinea Grass Need?
Guinea Grass thrives in full sun.
Light Requirement
Full sun
What Temperature and Humidity Does the Guinea Grass Prefer?
Megathyrsus maximus grows best at temperatures of 65–85°F. Guinea Grass prefers humidity levels of 40–70%.
Temperature
65–85°F
Humidity
40–70%
What Soil Mix Works Best for a Guinea Grass?
Well-draining sandy loam with good fertility. Good drainage is essential for Guinea Grass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Guinea Grass?
Feed Guinea Grass every 8 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 8 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 Guinea Grass?
Repot every 1-2 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 Guinea Grass?
Guinea Grass can be propagated through seeds, division of clumps.
Is the Guinea Grass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Guinea Grass, 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 Guinea Grass?
Guinea Grass is susceptible to armyworms, cutworms, aphids. 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 Guinea Grass Need?
Guinea Grass grows outdoors in USDA Zone 13b. It survives winters down to planting zone 13b. Guinea Grass is native to Africa and Yemen. In cooler regions, grow Guinea Grass as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 13b
Keep exploring plants
Guinea Grass 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 Megathyrsus genus — compare its care with other Megathyrsus species on PlantoScan.
Megathyrsus is part of the Poaceae plant family — browse all Poaceae genera and species.
Guinea Grass 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: Megathyrsus maximus (Jacq.) B.K.Simon & S.W.L.Jacobs, family Poaceae (first published in Austrobaileya 6: 572 (2003)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Guinea Grass, 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.
- Hardiness zone: USDA Zone 13b, calculated from the plant's minimum temperature.
- 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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