Purple weeds in lawns usually present a dilemma for many homeowners. While the beautiful purple blooms, coupled with the culinary and medicinal uses of these weeds are desirable, they can quickly spread through your lawn and wreak havoc on your turfgrass.
To effectively control purple-flowered weeds on your lawn, you need to first off identify which type of purple weed it is before applying the right herbicide or weed killer.
Common Purple Weeds in Lawn (Flowers)
Most of the purple-flowered weeds that sprout on lawns belong to the mint family. Common lawn weeds with purple flowers include Henbit, Ground Ivy, Purple Deadnettle, Wild Violet, Forget-Me-Not, Creeping Thistle, and Common Thistle. Also, this blog article doesn’t imply that the weeds listed here only develop purple blooms, as the flowers may also be pink, white, or even blue at other times.
Also known as Lamium amplexicaule, Henbit is a common purple-flowered weed belonging to the mint family. You can easily identify this weed plant via its square-shaped stem and its deeply-lobed, rounded leaves. Henbit leaves are very hairy and those located on the upper section of the stem attach directly to the stem as they lack petioles.
Unlike other types of purple weeds that may sprout in the middle of the lawn, henbit typically appears at the edges of the turf. This winter annual spreads via seed and also has an ascending growth pattern. Though henbit is often confused with purple deadnettle, you can easily tell these two apart as the former has a droopier and shorter appearance.
If you find the purple blooms attractive, you can keep henbit on your lawn, so long as too many of them don’t sprout up. Even better, it has both nutritional and medicinal values. Henbit seeds can also be used as chicken food.
However, if none of the above benefits interest you, consider eradicating henbit from your lawn to boost your turf’s chances of healthy growth. Herbicides are best applied in early spring before the weed has a chance to produce flowers that’ll form seeds. If you apply weed killer too late, the seeds will have already spread on the lawn and your efforts will be futile.
Ground ivy (creeping charlie)
Ground Ivy is a broadleaf weed that often invades gardens and lawns. In the spring, it sprouts and spreads fast, choking out your turfgrass in the process. The purple blossoms that ground ivy plants develop upon maturity may seem striking to the eye, but this should be a warning sign that your turf is at risk.
Note: Unlike Henbit and Purple Deadnettle that are winter annual weeds, Ground Ivy is a perennial shrub. It can, therefore, produce flowers and seeds through more than one growing season.
Ground Ivy identification and differentiation from other similar weeds is easy. Apart from the color of the flowers, you’ll also notice that each bloom culminates in four lobes. Ground Ivy blossoms appear in late spring-early summer.
Note: Creeping Charlie/ Ground Ivy competes for nutrients with your turf grass, choking the grass out in the process. And since they spread by way of underground rhizomes, they’re hard to kill using manual methods like uprooting and mowing.
To effectively kill Ground Ivy on your lawn, use a selective herbicide used to kill broadleaf weeds. You can also use glyphosate (a non-selective herbicide) but only as spot treatments, to avoid harming your turfgrass. Meanwhile, to prevent future invasions of Ground Ivy on your grass, maintain the turf well by watering, fertilizing, and mowing accordingly.
Purple Deadnettle, botanically referred to as Lamium purpureum, is a winter annual weed that regularly invades poorly-maintained lawns. This weed species is renowned for its characteristic purple or pink flowers that sprout from mid-spring to early summer. Four petals come together to form the tubular-shaped flower.
Note: Purple Deadnettle leaves typically spot purple-colored tips. The triangular leaves have a droopy growth pattern.
You can easily identify Purple Deadnettle by its square-shaped stem that lacks foliage at the base and only develops leaves from the upper section. Purple Deadnettle leaves attach to the stem by way of petioles. This is a key differentiating factor between this weed species and henbit, another mint weed that looks like purple deadnettle but whose leaves lack petioles and attach directly to the stem.
To effectively get rid of Purple Deadnettle on your lawn, spray the turf with a selective herbicide. The best time to do so is in the spring before the weed starts producing flowers and dispersing seeds. If you apply your weed killer after seeds are produced, expect to deal with more Purple Deadnettle weed plants on your lawn in the near future.
Note: You can also effectively use herbicides on Purple Deadnettle in the fall. Other methods of controlling this weed species on lawns include tillage and solarization.
Wild violet, botanically referred to as Viola Odorata, is an invasive perennial weed that develops violet-colored flowers. You can distinguish this weed from other purple-flowered weeds by its heart-shaped foliage and petals. While the purple blooms are beautiful to look at, this weed will quickly propagate via rhizomes and take over your lawn if not promptly controlled.
Wild violet is difficult to eliminate on turfs since it spreads via both seed and underground rhizomes. Thus, even if you apply a pre-emergent for the seeds and mow the shoots, more wild violets are still likely to sprout via rhizomes in nearby areas on the lawn.
The ability to spread in multiple ways, coupled with superior tolerance to shady and dry conditions makes wild violet a resilient weed whenever it grows. For small infestations, you can get rid of this weed species by hand-pulling/uprooting each weed plant. For larger infestations, though, the application of a chemical herbicide is your best bet.
Scientifically referred to as Myosotis sylvatica, Forget-Me-Not is a weed species that often develops blue flowers, but in some cases the blooms are purple-colored. The flower petals are round in shape and the center has a yellow hue. This annual weed thrives in partial or full sunlight, while also preferring well-drained, but moderately moist soils.
Note: Vigorous growth in Forget-Me-Notes has been noted to be more prevalent in the Midwestern states.
Many homeowners love to let this weed grow freely in their gardens and lawns due to its various culinary uses. However, Forget-Me-Not can vigorously spread on your lawn and deny your grass of essential nutrients. Peak growth season is in the summer, during which Forget-Me-Not may spread and kill your entire turf.
Creeping Thistle, also known as Canada Thistle, is a perennial weed species known for its resilience on lawns. This quality can be attributed to its deep-rooting nature, which allows the weed to thrive in low-nutrient lawn soil and choke out the existing turfgrass.
Creeping Thistle is identifiable by its spiny spear-shaped foliage. Meanwhile, the flowers are arranged in clusters on the upper part of the plant and are purple in color. However, these blooms turn whitish from the onset of seed production.
It’s important to control Creeping Thistle using a herbicide before it takes over your lawn and crowds out your grass. Selective herbicides are preferable, as they won’t harm the grass. However, if you’re going to use a non-selective systemic herbicide, apply as a spot treatment (not spraying) to avoid killing your turf grass as well.
Common Thistle, also referred to as Spear Thistle or Bull Thistle is a type of lawn weed that features purple or pink blossoms that feel fluffy to the touch. These flowers are usually visible from mid-summer- mid-fall. Meanwhile, common thistle features long leaves and stems, both of which are covered in barbs.
Common Thistle spreads via seeds, which are readily dispersed by wind, and may take over your lawn and cause turf stress soon enough. As such, you should control the weed by preventing it from flowering.
There are many ways of controlling Common Thistle on turfs. Regular mowing will significantly prevent flowering. Manual uprooting is also practicable for minor infestations. However, for severe Common Thistle invasion on your lawn, use a selective herbicide to completely get rid of the weed.
Also known by its species name, Prunella vulgaris, Selfheal is another mint weed that also produces purple blooms. Meanwhile, the leaves are oval-shaped, with two leaves located at the base of each flower.
Note: The stems on mature selfheal weeds are smooth but visibly hairy on young plants.
It’s difficult to control Selfheal by mowing, as it grows close to the ground, easily surviving the mower blades as you mow. Within a short while, this weed may spread all over your lawn and choke your turfgrass.
More effective control for Selfheal is herbicide application. The best time to spray weed killer on this weed is in the spring when it’s actively growing. Autumn application also produces great results. Use a selective herbicide to kill off Selfheal without damaging your desirable turf grass as well.