The short answer: If you’re seeing purple flowers in your Tulsa lawn in late winter or early spring (February through April), it’s almost certainly henbit or purple deadnettle, both winter annual weeds that germinate in fall and bloom in spring. If you’re seeing purple flowers later in the season, it could be wild violets (a perennial that’s very hard to control) or creeping Charlie/ground ivy. These weeds are extremely common in Oklahoma and indicate a gap in fall pre-emergent coverage for the annuals or an established perennial problem for violets. The good news: proper identification leads to proper treatment, and these weeds can be managed with the right approach.
Henbit: The Most Common Purple Flowering Lawn Weed in Tulsa
Henbit (Lamium amplexicaule) is the purple-flowered weed you’re most likely seeing if it’s late winter or early spring:
Identification: Square stems (a characteristic of the mint family). Heart-shaped leaves that clasp directly to the stem without a stalk. Small tubular purple-pink flowers clustered at the top of the plant. Grows 4-12 inches tall. Has a distinctive “layered” appearance with leaves wrapping around the stem at intervals.
Life cycle: Winter annual. Seeds germinate in fall (September-November), plants grow slowly through winter, then explode with growth and flowering from late February through April. Plants die after setting seed in late spring. Those seeds wait in the soil to germinate next fall.
Why it’s in your lawn: Henbit thrives in thin turf, shady areas, and disturbed soil. If your lawn has bare spots or thin areas going into fall, henbit seeds find opportunity. Lack of fall pre-emergent allows germination.
Control: Fall pre-emergent (applied in September) prevents germination. Post-emergent broadleaf herbicides work on young plants in fall or winter but become less effective once plants are large and flowering in spring. By the time you see purple flowers, the plant is about to die anyway and has already set seed for next year.
Purple Deadnettle: Henbit’s Close Cousin
Purple deadnettle (Lamium purpureum) is often confused with henbit and may be growing alongside it:
Identification: Also has square stems and purple flowers. Key difference: leaves are triangular (not heart-shaped), have stalks (not clasping), and the upper leaves have a distinctive purplish-red tint. Flowers are similar but slightly smaller than henbit. Overall, a more compact growth habit.
Life cycle: Same as henbit. A winter annual that germinates in fall, flowers in late winter/early spring, and dies after setting seed.
Control: Same as henbit. Fall pre-emergent prevents it. Post-emergent broadleaf herbicides control young plants. Often found growing right alongside henbit in the same lawn.
Wild Violets: The Perennial Problem
If you’re seeing purple flowers later in spring (April-May) or the plants come back year after year in the same spots, you may have wild violets:
Identification: Heart-shaped leaves on long stalks, very different from henbit. Distinctive five-petaled purple flowers on their own stalks. Low-growing, spreading plants that form clumps. Leaves have a waxy texture that resists herbicide absorption.
Life cycle: Perennial. Plants survive year after year, spreading both by seed and underground rhizomes. This is what makes them so difficult to control. You can’t prevent them with pre-emergent because they’re already established.
Why they’re hard to control: That waxy leaf coating makes herbicide absorption difficult. The rhizome system means killing the top growth doesn’t kill the plant. They thrive in shade and moist conditions where grass struggles.
Control: Requires persistent treatment, often multiple applications over multiple seasons. Triclopyr-based herbicides work better than standard 2,4-D products. Fall applications when plants are moving energy to roots can be more effective. Building thicker turf helps compete with established violets. Many homeowners learn to tolerate some violets rather than wage constant war.
Creeping Charlie (Ground Ivy): Another Purple Possibility
Creeping Charlie, or ground ivy (Glechoma hederacea), has small purple flowers and spreads aggressively.
Identification: Round or kidney-shaped leaves with scalloped edges on long stalks. Square stems (mint family). Small funnel-shaped purple flowers in spring. Strongly aromatic when crushed (minty smell). Spreads by above-ground stolons that root at nodes.
Life cycle: Perennial that spreads aggressively. Very shade tolerant. Thrives in moist areas where grass struggles.
Control: Difficult to control because of aggressive spreading. Triclopyr-based herbicides are most effective. Multiple applications are usually required. Improving drainage and reducing shade helps grass compete.
Quick Identification Guide
Weed
When It Blooms
Key Feature
Type
Henbit
Feb-April
Heart leaves clasp stem.
Winter annual
Purple Deadnettle
Feb-April
Triangular leaves, purple top
Winter annual
Wild Violet
April-May
5-petal flowers, waxy leaves
Perennial
Creeping Charlie
April-June
Scalloped round leaves, minty smell
Perennial
How to Prevent Purple Weeds Next Year
For henbit and purple deadnettle (winter annuals): A fall pre-emergent application in September prevents germination. This is the most effective control. Once you see purple flowers in spring, it’s too late for that season. You’re preventing next year’s problem.
For all purple weeds: Build thicker turf. These weeds exploit thin areas, shade, and bare spots. Proper fertilization, overseeding thin areas, and addressing soil compaction all help grass outcompete weeds.
For perennials (violets, creeping Charlie): Persistent post-emergent treatment over multiple seasons. Fall applications are often more effective. Accept that complete elimination may not be realistic; focus on management and reducing spread.
Proper Identification Leads to Proper Treatment
For more than 25 years, Complete Lawn Care has been a trusted lawn care provider in the Tulsa area. We believe great results don’t come from guessing. They come from experience, science, and continual improvement.
That’s why we invest heavily in leadership training, research and development, and product testing, ensuring our team stays current on the latest turf products, application methods, and correction strategies. We’ve also implemented one of the few agronomy-supported programs in Tulsa, working directly with an industry expert who helps guide our application timing, product selection, and ongoing improvements based on proven agronomic science.
Our technicians are trained to identify what’s actually in your lawn and recommend the right approach. Different weeds require different timing and different products. We don’t just spray and hope. We identify the problem and apply what actually works.
Experience tells us what to do. Science tells us when and why. Your lawn deserves the best.
The Bottom Line
Late winter/early spring purple flowers = henbit or purple deadnettle. Winter annuals prevented by fall pre-emergent.
Later spring purple flowers are likely wild violets or creeping Charlie. Perennials requiring persistent treatment.
Fall pre-emergent is the key prevention for annuals. A September application prevents spring problems.
Thick turf is your best long-term defense. Build healthy grass that outcompetes weeds.
Need Help Identifying or Controlling Lawn Weeds?
At Complete Lawn Care, we can identify what’s growing in your Tulsa lawn and develop a plan to manage it. Our 7-step program includes properly timed pre-emergent applications to prevent winter annuals like henbit, plus ongoing weed management throughout the season.
Phone: (918) 605-4646
Email: [email protected]
Online: completelawncaretulsa.com/get-a-quote
Proudly serving Tulsa, Broken Arrow, Owasso, Jenks, Bixby, Sand Springs, Collinsville, and surrounding Oklahoma communities since 2000.