Is it a perennial or annual?

It is typically an annual, but can act as a short lived perennial in mild climates.

How do I get rid of it?

Maintain a dense lawn to shade out seedlings and prevent seed germination.

Plant guide

Annual bluegrass.

Poa annua

Pronounced POH-ah AN-yoo-ah

Also known as Annual Bluegrass, Annual Meadow Grass, Annual Meadow-Grass, Annual Poa, Winter Grass

Annual Meadow-grass — Photo by Eric Lamb (CC BY) via iNaturalist

This is a common, opportunistic grass that often shows up in lawns and gardens as a winter annual. It grows in small, light green tufts and spreads rapidly by seed. Most gardeners consider it a pesky weed because it thrives in compacted soil and cool, moist conditions.

Another photo of Annual bluegrass — Photo by Karen Fry (CC BY) via gbif

At a glance

Care level: Easy
Plant type: Grass
Light: Full sun to partial shade
Indoor light: Direct sun
Water: Every 1 to 3 days
Mature size: 6 to 12 inches
Growth rate: Fast
Hardiness: USDA 2 to 10
Bloom time: Early spring to late autumn

Care

Because this is typically viewed as a weed, you should focus on prevention through healthy lawn maintenance. Keep your grass thick and tall to shade out seedlings. If you spot it, pull it by hand before it drops its seeds.

Watering: It prefers consistently moist soil to thrive.
Feeding: It responds well to nitrogen, though it usually gets what it needs from standard lawn fertilizer.
Pruning: Regular mowing helps keep it from spreading seeds.
Repotting: It is rarely grown in containers, but it would need a refresh if it becomes root bound.
Soil: Moist, compacted soils
Soil pH: 6.0 to 7.0
Temperature: -40 to 30°C
Humidity: 40 to 80%

Safety

People: There is no known toxicity to humans.
Children: No specific risks exist for children, though it is a common weed in play areas.
Contact allergens: The leaf blades can cause minor skin irritation or cuts if handled roughly.
Airborne allergens: The pollen is a common trigger for seasonal hay fever.
Edibility: While not toxic, the foliage is too fibrous and unpalatable for human consumption.

How to identify it

Light green, soft leaf blades
Boat shaped leaf tips
Forms dense, low growing clumps
Produces light green seed heads
Ligule is prominent and membranous

Height: 0.05 to 0.3m
Spread: 0.05 to 0.2m
Leaves: light green, deciduous
Flowers: green, white, 0.1 to 0.3cm
Fruit: tan, Late spring to autumn

Problems to watch for

Dollar SpotCommon
Red ThreadCommon
Root RotUncommon
RustUncommon

By symptom

Plant problems by symptom

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Growing it

Propagation: seed
When to plant: spring, autumn

Encourage taller, more vigorous grasses to outcompete this species for light.

Grows well with

Kentucky Bluegrass · They often grow together in managed turf environments.

Similar species

Rough Bluegrass · It has a similar appearance but prefers much wetter soil conditions.

Science

Family: Poaceae
Genus: Poa
Order: Poales
Class: Liliopsida
Native range: Europe and temperate Asia.
Conservation: It is considered a widespread invasive weed in many regions.

It thrives in compacted soils and disturbed areas where other grasses struggle to grow.

Value to wildlife: seeds provide food for small birds
Pollinators: bees
Uses: ground cover, wildlife food source

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 5/9
Light: 7/9
Temperature: 5/9
Moisture: 6/9
Nutrients: 7/9

Taxonomy resolved against GBIF.

Questions people ask

Is it a perennial or annual?: It is typically an annual, but can act as a short lived perennial in mild climates.
How do I get rid of it?: Maintain a dense lawn to shade out seedlings and prevent seed germination.

Where the name comes from

The name Poa is the ancient Greek word for fodder, while annua refers to its annual growth habit.

Good to know

It is one of the most successful weeds in the world.
It can produce seeds even when mowed extremely short.
The name annua refers to its annual life cycle.

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This guide was generated with AI on September 26, 2026 and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.