Smooth Crabgrass Plant Care
Digitaria ischaemum (Schreb.) Muhl.
Updated · Sources · How we source care data
Digitaria ischaemum is a species of crabgrass known by the common names smooth crabgrass and small crabgrass. It is native to Europe and Asia, but it is known throughout much of the warm temperate world as an introduced species and often a common roadside and garden weed.
Every 7–14 days
Full sun to partial shade
65–85°F
40–70%
At a glance
How do you care for Smooth Crabgrass?
Water Smooth Crabgrass 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 65–85°F (18–29°C) and 40–70% humidity. Fertilize it every 8 months during the growing season.
Where Is the Smooth Crabgrass Native To?
- Albania
- Austria
- Belarus
- Belgium
- Bosnia and Herzegovina
- Bulgaria
- Croatia
- Cyprus
- Czechia
- Denmark
- Estonia
- Finland
- France
- Germany
- Greece
- Hungary
- Iceland
- Ireland
- Italy
- Latvia
- Lithuania
- Luxembourg
- Malta
- Moldova
- Montenegro
- North Macedonia
- Norway
- Poland
- Portugal
- Romania
- Russia
- Serbia
- Slovakia
- Slovenia
- Spain
- Sweden
- Switzerland
- The Netherlands
- Ukraine
- United Kingdom
What Is the Smooth Crabgrass?
Smooth Crabgrass (Digitaria ischaemum) belongs to the Poaceae family within the Digitaria genus. Smooth Crabgrass is native to Europe and Asia. Smooth Crabgrass is also known as Small Crabgrass.
Smooth Crabgrass displays an upright, spreading grass growth habit, reaching up to 3 ft tall with a spread of approximately 2 ft. Smooth Crabgrass produces small inconspicuous flowers on tall spikes.
Leaf size: approximately 12 inches.
How Often Should You Water a Smooth Crabgrass?
Digitaria ischaemum 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 Smooth Crabgrass Need?
Smooth Crabgrass thrives in full sun to partial shade.
Light Requirement
Full sun to partial shade
What Temperature and Humidity Does the Smooth Crabgrass Prefer?
Digitaria ischaemum grows best at temperatures of 65–85°F. Smooth Crabgrass prefers humidity levels of 40–70%.
Temperature
65–85°F
Humidity
40–70%
What Soil Mix Works Best for a Smooth Crabgrass?
Well-draining sandy loam with good fertility. Good drainage is essential for Smooth Crabgrass to prevent waterlogging, which leads to root rot and fungal issues.
How Often Should You Fertilize a Smooth Crabgrass?
Feed Smooth Crabgrass 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 Smooth Crabgrass?
Divide and 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 Smooth Crabgrass?
Smooth Crabgrass can be propagated through seeds, division of clumps. Similar propagation techniques also apply to digitaria californica plant care, which shares the same genus.
Is the Smooth Crabgrass Toxic to Pets and Children?
Pet safety not verified
The ASPCA does not list Smooth Crabgrass, 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 Smooth Crabgrass?
Smooth Crabgrass is susceptible to aphids, grasshoppers, armyworms. 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 Smooth Crabgrass Need?
Smooth Crabgrass grows outdoors in USDA Zone 13b. It survives winters down to planting zone 13b. Smooth Crabgrass is native to Europe and Asia. In cooler regions, grow Smooth Crabgrass as a houseplant or bring it indoors before the first frost.
Hardiness Zone
Zone 13b
Keep exploring plants
Smooth Crabgrass 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 Digitaria genus — compare its care with other Digitaria species on PlantoScan.
Digitaria is part of the Poaceae plant family — browse all Poaceae genera and species.
Smooth Crabgrass thrives in bright light and direct sun — see other bright-light plants.
More Digitaria Species
Other Digitaria species in PlantoScan's care catalogue share similar watering, light, and soil preferences:
Sources
- Scientific name & taxonomy: Digitaria ischaemum (Schreb.) Muhl., family Poaceae (first published in Descr. Gram. : 131 (1817)) — World Flora Online record, IPNI name record.
- Pet toxicity: Pet safety not verified: the ASPCA does not list Smooth Crabgrass, 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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