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Guide botanique

Crabgrass.

Digitaria sanguinalis

Prononciation di-ji-TARE-ee-uh san-gwin-AL-iss

Aussi appelée Crab Finger Grass, Crab-grass, Hairy Finger-grass, Crabgrass, Crap-grass, Crop Grass, Early Crab Grass, Hairy Crabgrass, Hairy Finger Grass

Hairy Crabgrass
Photo de Patrick Hacker (CC BY) via iNaturalist

Crabgrass is a common annual weed that thrives in thin lawns and disturbed soil. It produces many seeds that germinate quickly when soil temperatures rise in the spring. Most gardeners consider it a nuisance due to its aggressive spreading habit.

En un coup d'œil

Care level
Easy
Plant type
Annual grass
Light
Full sun
Indoor light
direct
Water
Every 3 to 7 days
Mature size
Up to 60 cm tall
Growth rate
fast
Hardiness
USDA 3 to 10
Bloom time
Mid summer to early autumn

Entretien

Control this weed by maintaining a thick, healthy lawn to shade out seedlings. If you spot it, pull it by hand before it drops seeds. Watch for new sprouts in early spring when soil warms up.

Watering
Keep soil moist for germination but it tolerates drought once established.
Feeding
Does not require intentional fertilization.
Pruning
Mowing prevents seed head formation.
Repotting
This is a wild weed and not typically potted.
Soil
Well-draining, disturbed soil
Soil pH
5.0 to 7.5
Temperature
5 to 35°C
Humidity
30 to 80%
Drought tolerance
high
Lifespan
Annual, typically 1 season

Sécurité

People
It is not considered toxic to humans.
Pets
This plant is generally considered non-toxic to cats and dogs.
Children
The sharp, pointed seed heads can be irritating if they get stuck in clothing or skin, so keep an eye on small children playing in patches.
Contact allergens
The rough, hairy leaf blades can cause minor skin irritation or contact dermatitis in sensitive individuals.
Airborne allergens
The pollen is a common seasonal allergen for many people during late summer.
Edibility
While the seeds are technically edible, they are tiny, labor intensive to harvest, and often contaminated by soil pathogens or herbicides.

Comment l'identifier

  • Spreading, prostrate growth habit
  • Light green, hairy leaf blades
  • Finger like seed head clusters
  • Forms dense, low mats
Height
0.15 to 0.6m
Spread
0.3 to 0.9m
Leaves
light green, deciduous
Flowers
green, purple, 0.5 to 1cm
Fruit
tan, Autumn

Problèmes courants

  • Rust fungus Appears as reddish brown pustules on the leaves during humid weather.

La cultiver

Propagation
seed
When to plant
spring
Overwintering
The plant dies completely with the first hard frost, leaving behind a massive seed bank in the soil.

Because this plant is a highly competitive weed, it is best not to include it in intentional garden guilds.

Bonnes associations

  • Common Purslane They often share the same disturbed soil habitats and thrive under similar moisture conditions.

À éloigner de

  • Kentucky Bluegrass This grass aggressively competes with and is often choked out by the rapid growth of crabgrass.

Espèces similaires

  • Smooth Crabgrass It looks very similar but has hairless leaves and a slightly smaller growth habit.

Science

Family
Poaceae
Genus
Digitaria
Order
Poales
Class
Liliopsida
Native range
Native to Europe and parts of Asia, now naturalized worldwide.
Conservation
It is widely considered an invasive weed in many regions and is not of conservation concern.

It thrives in disturbed soils and open areas where it can quickly outcompete native vegetation for sunlight and nutrients.

Value to wildlife
seed source for birds, forage for small mammals
Pollinators
beetles
Uses
forage for livestock, soil erosion control

Au fil des saisons

JFMAMJJASOND
Flowering
Fruiting
Foliage

Repères écologiques

Salinity
3/9
Soil reaction
6/9
Light
8/9
Temperature
7/9
Moisture
5/9
Nutrients
6/9

Taxonomie vérifiée avec le GBIF.

Ce qu'on demande souvent

Is it good for lawns?
Generally no, as it grows rapidly and creates unsightly, coarse clumps that crowd out desirable turf grasses.
How do I get rid of it?
Hand pull before it sets seed or use a pre emergent herbicide in early spring.

D'où vient le nom

The genus name Digitaria comes from the Latin word digitus, meaning finger, referring to the finger like arrangement of the seed spikes. The species name sanguinalis means blood red, describing the plant's color.

Bon à savoir

  • The name sanguinalis refers to the reddish, blood like tint the leaves often develop as they mature.
  • It is one of the most widespread weeds in agricultural fields across the globe.
  • Seeds can remain viable in the soil for several years.

Ton crabgrass a mauvaise mine ?

Cette page est un guide général. Pocket Botanist diagnostique les problèmes directement à partir d'une photo de ta plante, adapte l'arrosage à sa luminosité et te prévient quand il faut t'en occuper.

Télécharger l'appli

Ce guide a été généré par IA et vérifié avec la taxonomie du GBIF. Il s'agit d'informations générales, et non de conseils horticoles ou vétérinaires. Découvre comment nous concevons ces guides.