Veronica arvensis

Speedwell Identification & Control

Corn Speedwell, also known as Veronica, is an exceptionally common, low-growing annual broadleaf weed in the plantain family. Native to Europe but thoroughly naturalized globally, it is a major nuisance in home lawns and golf courses. It features a creeping, mat-forming growth habit with egg-shaped leaves showing scalloped edges, and tiny, light-blue 4-petaled flowers.

Sunlight Full Sun to Shade

Watering Tolerance Moderate

Soil Adaptability Any Soil / Loam / Moist Clay

Growth Temp 5°C - 30°C

Danger / Toxicity Pet Safe / Mat-Forming Weed

Botanical macro photography of Speedwell (Veronica arvensis) - Plant AI care and control database

How to Identify Speedwell

A low-growing, creeping annual forming light-green mats, with scalloped opposite leaves, and tiny light-blue 4-petaled flowers.

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Scalloped Opposite Leaves: Lower leaves are egg-shaped, opposite (1 cm long) with coarsely scalloped margins, while upper leaves are narrow bracts.
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Tiny Blue 4-Petaled Flowers: Small, inconspicuous light-blue flowers with exactly 4 petals, blooming individually in upper leaf joints.
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Heart-Shaped Seed Capsules: Small, flat, heart-shaped seed capsules (4 mm) arranged along the upper stems.

💡 Plant AI Tip: Speedwell is highly resistant to mowing! Stems creep horizontally flat on the soil, well below the mower height. Mowing only clips the flowers, but the creeping mats remain intact.

Complete Care & Management Guide

Access highly technical, scientific management directives to control or cultivate Speedwell effectively.

Requires consistent moisture. It thrives in damp, wet, poorly drained soils, riverbanks, and overwatered garden beds. Allowing the top soil layer to dry out helps slow its spread.

Resistant to mowing. Horizontal stems creep flat along the soil beneath mower height. Mowing actually removes competing turf grass, allowing Speedwell to expand.

Highly aggressive. It absorbs high levels of nitrogen and potassium, outcompeting pasture grasses and garden flowers. Shifting soil fertility helps grass compete.

Highly versatile. Thrives in Full Sun but exhibits high shade tolerance, allowing it to colonize dense forest understories and dark house alleyways.

Adapts to clay, rich loam, sandy loam, and gravelly forest edges, provided the substrate is well-drained. It struggles in swampy soils.

Spreads via seeds and rooting stolons. The seed pods explode when dry, flinging seeds up to 10 feet horizontally. A single plant can produce thousands of seeds.

Extremely cold-hardy perennial. Leaves die back under freezing winter temperatures, but the woody taproot crown survives easily, sprouting in early spring.

Features a shallow but extremely dense, tough fibrous root network anchored to creeping stolons that root at every node touching the soil.

Occasionally targeted by aphids, but pests rarely cause significant damage to this highly robust annual grass.

Subject to **Browning Rust** and **Leaf Spots** in damp autumns, though diseases rarely kill the weed before it successfully sets seed.

To control Speedwell organically, manually dig up young rosettes in spring before they flower, use a hoe to scrape seedlings, and mulch garden beds heavily to block seed light.

Common Diseases & Treatment

Fungal Spot

Symptoms: Symptoms: Water-soaked, circular black or dark brown spots with bright yellow halos appearing on the waxy green leaves.

Action: Action: Clip and dispose of infected foliage. Avoid overhead watering to keep leaf surfaces dry, and ensure proper air circulation.

Creeping Mat Invasion

Symptoms: Symptoms: The turf grass is completely replaced by dense, flat green mats of three-leaf clover.

Action: Action: Feed your lawn grass with nitrogen. Grass requires soil nitrogen to grow, while clover creates its own. Shifting soil fertility favors grass.

Frequently Asked Questions

How is Speedwell different from other blue-flowered weeds?

Speedwell (Veronica) always has flowers with exactly 4 petals (three large ones and one smaller bottom petal) that are pale blue with white centers, and distinct heart-shaped seed capsules. Other weeds like Henbit have tubular purple flowers.

Is Speedwell toxic to dogs?

No, Speedwell is completely non-toxic and safe for dogs and cats. However, it is an aggressive lawn competitor that will quickly crowd out weak turf grass.

Can I kill Speedwell by mowing it low?

No. Low mowing will actually make the problem worse! Its stems creep horizontally flat on the ground, so mowing will miss the weed while cutting your lawn grass, giving speedwell more sunlight to expand.

What is the best way to get rid of it?

Because it is an annual, the key is to prevent it from dropping seeds. Hand-pull the shallow vines in early summer before they flower, and apply thick mulch to garden beds.