North America Non-native Plant

Guineagrass

Botanical name: Urochloa maxima

USDA symbol: URMA3

Life cycle: perennial

Habit: grass

Native status: Non-native, reproduces and persists in the wild in Hawaii âš˜ Non-native, reproduces and persists in the wild in the lower 48 states âš˜ Non-native, reproduces and persists in the wild in Pacific Basin excluding Hawaii âš˜ Non-native, reproduces and persists in the wild in Puerto Rico âš˜ Non-native, reproduces and persists in the wild in the U.S. Virgin Islands  

Synonyms: Megathyrsus maximus (Jacq.) B.K. Simon & S.W.L. Jacobs (MEMA22)  âš˜  Panicum maximum Jacq. (PAMA4)  âš˜  Panicum maximum Jacq. var. trichoglume Robyns (PAMAT2)   

Guinea Grass: A Large, Hardy Grass for Warm Climates If you’re looking for a robust, fast-growing grass that can handle heat and drought, guinea grass (Urochloa maxima) might catch your attention. This substantial perennial grass, also known simply as guinea grass, is a powerhouse plant that can reach impressive heights ...

Guinea Grass: A Large, Hardy Grass for Warm Climates

If you’re looking for a robust, fast-growing grass that can handle heat and drought, guinea grass (Urochloa maxima) might catch your attention. This substantial perennial grass, also known simply as guinea grass, is a powerhouse plant that can reach impressive heights of up to 5 feet. But before you decide whether it’s right for your landscape, let’s dive into what makes this grass tick and whether it deserves a spot in your garden.

What Exactly is Guinea Grass?

Guinea grass is a large, bunch-forming perennial grass that belongs to the same family as your lawn grass, but operates on a much grander scale. With its rapid growth rate and dense summer foliage, it creates quite the presence wherever it grows. The plant produces small, inconspicuous yellow flowers during mid-summer, though most people grow it for its substantial grass structure rather than any ornamental appeal.

You might also see this plant referred to by its scientific synonyms, including Panicum maximum or Megathyrsus maximus, depending on which botanical reference you’re using.

Where Does Guinea Grass Come From and Where Does it Grow?

Here’s something important to know right up front: guinea grass isn’t native to North America. It’s been introduced from its original range and has established itself across many warm regions of the United States. You’ll find it growing in Alabama, Arizona, California, Florida, Georgia, Hawaii, Louisiana, Oklahoma, Texas, and several U.S. territories including Guam, Puerto Rico, and the Virgin Islands.

This wide distribution tells you something important about guinea grass – it’s quite adaptable and tends to stick around once it gets established in an area.

The Good, The Bad, and The Practical

Why you might want guinea grass:

  • Extremely drought tolerant once established
  • Rapid growth rate means quick coverage
  • Can handle various soil types from coarse to fine textures
  • Tolerates both wetland and upland conditions
  • High fire tolerance
  • Reaches an impressive 5-foot height

Why you might want to think twice:

  • It’s a non-native species that can spread and persist
  • Requires a very warm climate (minimum 300 frost-free days)
  • Intolerant of shade
  • Not particularly ornamental
  • Takes up a lot of space due to its size
  • Offers minimal benefits to local wildlife and pollinators

Growing Conditions and Care

If you’re considering guinea grass, you’ll need the right climate and conditions. This plant is definitely not for everyone or every location.

Climate Requirements:

  • USDA zones 9-11 (needs temperatures above 22°F)
  • Requires at least 300 frost-free days annually
  • Thrives in areas with 28-100 inches of annual precipitation

Soil and Site Conditions:

  • Adaptable to various soil textures
  • Prefers slightly acidic soil (pH 5.2-6.9)
  • Needs full sun – shade intolerant
  • Medium fertility requirements
  • Good drainage preferred but can handle some moisture variation

Planting and Establishment

Guinea grass is typically grown from seed, and you’ll find it routinely available commercially. With over a million seeds per pound, a little goes a long way! The seeds have moderate spread rates and medium seedling vigor, so expect steady but not explosive initial establishment.

Plant seeds during the active growing season of summer and fall when temperatures are warm. Once established, the plants have a relatively short lifespan but can self-seed under the right conditions.

A Word About Native Alternatives

Since guinea grass is non-native, you might want to consider native grass alternatives that could provide similar benefits while supporting local ecosystems. Depending on your region, native bunch grasses or warm-season prairie grasses might give you the height and drought tolerance you’re looking for while providing better habitat for local wildlife.

Some options to research for your area might include native switchgrass, big bluestem, or other regional prairie grasses that can offer impressive stature and resilience.

The Bottom Line

Guinea grass is a no-nonsense, utilitarian plant that excels in hot, dry conditions where you need substantial grass coverage quickly. It’s not going to win any beauty contests, but if you have the right climate and space, and you need a tough, fast-growing grass for large areas, it could fit the bill.

However, given its non-native status and tendency to persist and spread, it’s worth exploring native alternatives first. Your local extension office or native plant society can point you toward indigenous grasses that might serve your needs while supporting local wildlife and maintaining ecological balance.

If you do choose guinea grass, plant it responsibly and be mindful of its potential to spread beyond where you originally intended. Sometimes the most practical choice isn’t necessarily the most ecological one, but understanding the trade-offs helps you make informed decisions for your specific situation.

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Arid West

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Atlantic and Gulf Coastal Plain

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Caribbean

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Eastern Mountains and Piedmont

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Great Plains

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Hawaii

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

Western Mountains, Valleys, and Coast

FAC

Facultative - Plants with this status can occur in wetlands and non-wetlands

FACU

South Pacific Islands

Guineagrass

Classification

Group

Monocot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Liliopsida - Monocotyledons

Subclass

Commelinidae

Order

Cyperales

Family

Poaceae Barnhart - Grass family

Genus

Urochloa P. Beauv. - signalgrass

Species

Urochloa maxima (Jacq.) R. Webster - guineagrass

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA