Lawn Weeds with Blue Flowers (9 Types) (2024)

Roses are red, violets are blue, turns out a lot of lawn weeds are too. Flowers in a field are lovely. Flowers in a garden, divine. Lawn weeds with blue flowers all over your turf, uh oh! I have noticed that most of these lawn weeds have tiny blue flowers making them hard to see at first. However, if you pay close attention, I will show you how to identify 9 of the most common lawn weeds with blue flowers!

Most Common Lawn Weeds with Blue Flowers (Short Answer)

Siberian Squill, Common Blue Violet, Tiny Bluets, Asiatic Dayflower, Henbit, Carpet Weed, and Blue Oxalis are all lawn weeds with small blue flowers. Other plants like Columbine Aquilegia and Creeping Bellflower are lawn weeds with blue flowers that sneakily invade a turf.

A Closer Look at Lawn Weeds with Blue Flowers

Now that you have looked closely at your lawn and have seen tiny blue flowers you are probably thinking, what are the blue flowers on my lawn? Below, I’m going to talk about 9 common lawn weeds with blue flowers that can mess up your turf. Most of them are pretty to look at, good for pollinators, but unfortunately in the wrong place when they’re smack in the middle of your lawn.

These weeds are mostly harmless but some can be a little more dangerous. It’s best to learn exactly how to get rid of blue flowers on the lawn so as to not take any chances, and I am going to show you just that!

Siberian Squill (Scilla siberica)

What It Does: A small, low-growing weed that blooms early in the spring, Siberian Squill can spread quickly. Although it doesn’t grow very tall, this lawn weed with blue flowers can spread outwards rapidly. The flowers bloom continuously and bloom almost as fast as the rest of the weed grows. When it begins to get hot and dry, Siberian Squill drops seeds that allow it to grow again when the temperatures fall. This blue weed is toxic to humans, dogs, and cats!

What It Looks Like: Similar to blades of grass, this weed’s leaves grow straight out like swords. The leaves grow from the base of the plant and point out. This growth pattern makes it easy to see the blue flowers early in the season. It grows out in patches and spreads by staying low in the turf grass. The flowers of Siberian Squill drop like bells and open into little stars.

How to Get Rid of It: This is a tough weed to completely get rid of as it self-seeds and spreads by bulbs. If you catch it early you can hand pull, wearing gloves, and make sure to dig out the entire root. If it has infested a large area of turf you will need to suffocate it using black plastic, layers of cardboard, or any other method of suppression. As a last resort use glyphosate to kill any survivors.

Common Blue Violet (Viola sororia)

What It Does: Another lawn weed with small blue flowers, this plant spreads from fields and can infiltrate your lawn. Once it has germinated, it can spread by seed and rhizome. Blue Violet tends to grow quickly in the spring when it is cool and moist and then turn yellow and die back during full sun and summer heat. This leaves unsightly patches in an otherwise meticulous lawn.

What It Looks Like: This is a relatively small weed and stays around 4” tall and only 6” wide. It sprouts its leaves and flowers from the root, and the flowers of the common blue violet sit just slightly higher than the top leaves. In cool, moist, and slightly shaded conditions, these weeds are dark green. In full sun, hot and stressed conditions, the leaves may turn yellowish-green. The blue flowers form a star shape.

How to Get Rid of It: Mowing your lawn often in the spring can prevent these weeds from developing. When there are only a few violets, you can hand pull them easily. If there is already a large infestation, then you can use a broadleaf herbicide to spot treat the weeds.

Tiny Bluets (Houstonia pusilla)

What It Does: This blue weed is most likely to invade sparse areas of the lawn that are stressed. It stays very low to the ground and can hide amongst low-cut turf. This weed stays active during the winter and bolts, producing a stem and leaves, early in the spring.

What It Looks Like: This is a very small lawn weed. It grows to only 2 inches tall and produces tiny leaves each less than an inch long. Tiny Bluets are lawn weeds with tiny blue flowers, only growing to a quarter of an inch. The flowers bloom from early to mid-spring and then are replaced with seed pods.

How to Get Rid of It: Tiny Bluets have very weak taproots. They are delicate and easy to remove by hand. You should have no trouble removing any patches of these weeds that make their way into your yard. Just pull up any blue-flowered weeds you see in the early spring before they produce seeds.

Asiatic Dayflower (Commelina communis)

What It Does: This South Asia native weed is invasive and can spread through a yard quickly. It propagates by seed and can also create roots at leaf nodes on moist ground. This allows these weeds to form colonies that are much harder to remove.

What It Looks Like: Asiatic Dayflower is one of the few flowers that has a true blue color. Most other blue flowers are actually closer to purple or violet but this blue weed is blue. It can grow from 1 to 3ft and stands either upright or sprawls along the ground. It has dark green leaves that are about 5in long and each leaf axil produces a 1” flower stalk.

How to Get Rid of It: This lawn weed with blue flowers is tough to remove. It produces flowers quickly and will root from leaves. If it is just getting started on your lawn, you can hand pull it and completely remove it from your lawn. If there is a large infestation, you will need to use herbicide. This weed is resistant to glyphosate, so you will need a herbicide with flumioxazin.

Henbit (Lamium amplexicaule)

What It Does: This is a cold-resistant plant that grows low and produces small blue flowers. It can begin growing if there is a warm spell during the winter months. Henbit produces flowers and seeds in early spring and dies off when the temperatures rise. It leaves patches on your lawn and will pop up in greater numbers the following spring.

What It Looks Like: This low-growing weed has square greenish-purple stems. Henbit has egg-shaped leaves on opposite sides and grows prostrate, flat on the ground. This makes it hard to identify and renders mowing ineffective. The bluish flowers bloom in early spring and are arranged in a whorl pattern.

How to Get Rid of It: In the early spring, when you notice these blue flowers popping up, you can hand pull henbit to try and prevent it from dropping seeds. A post-emergent herbicide can also be used to treat the areas that were infested. The best way to prevent Henbit is to keep your turf thick and not over-water when spring starts.

Carpetweed (Ajuga pyramidalis)

What It Does: This lawn weed with tiny blue flowers can creep into a yard and spread far and wide. It is a ground cover and related to mint. It grows year-round and if left for more than a year, can become very well-rooted. It divides by rhizome and can choke out turf.

What It Looks Like: Carpetweed grows to a height of about 6 inches and has oval green leaves. It produces spiked inflorescence flowers that bloom from May through June. The leaflets on the flower alternate and have a reddish-purple hue. The flowers are small and blue.

How to Get Rid of It: Your best bet to remove this lawn weed with blue flowers is to catch it in its first year of growth. If you can pull it by hand in the first growing season, it will uproot very easily. If you missed it and it has become established, you will need to dig up the entire root and completely remove the weed from your yard.

Blue Oxalis (Parochetus communis)

What It Does: When a lawn is weak from neglect or stress, blue oxalis is likely to invade. It grows low and can hide amongst white clover and turf until it flowers. This weed grows quickly and produces hundreds of seeds in each seed pod. The seed pods explode when touched and can quickly cover your lawn.

What It Looks Like: Blue Oxalis resembles other types of sorrel and clovers. It has trifoliate leaves and grows to a height of 4” to 8” tall. The round leaves have white Vs pointing at the center of the weed. There is also a black circle covering the bottom part of each leaf. It puts up an intense blue pea flower and blooms from summer to fall.

How to Get Rid of It: Another common lawn weed with blue flowers, this weed is easily hand-pulled and best removed early in spring before it flowers. When manually removed, you need to pull out the entire root or it will regrow. Mowing high, watering your lawn, and fertilizing deeply can prevent Blue Oxalis from becoming an issue.

Columbine Aquilegia (Aquilegia vulgaris)

What It Does: A blue lawn weed that can show up on your turf is Columbine Aquilegia. It self-seeds and produces blooms prolifically throughout late spring and summer. The seeds germinate in similar conditions to a healthy lawn leading to a heavier infestation next spring. The sap of these weeds can cause skin irritation and care should be taken when removing them.

What It Looks Like: Aquilegia is usually a cultivated flower and finds its way from a flower bed onto a lawn. It has long, light green, lacey leaves and produces a thick stalk. Each stalk produces long thin branches that point up. At the end of each branch, a bell-shaped flower grows and unfurls bluish-purple petals.

How to Get Rid of It: If only a few of these lawn weeds with blue flowers show up, you can pull them by hand. If it is a larger patch, then it is best to mow the tops down before they produce seeds. If you keep them low, they won’t be able to self-seed or propagate.

Creeping Bellflower (Campanula rapunculoides)

What It Does: A very sneaky blue lawn weed that can reproduce via seed and rhizome, Creeping Bellflower is a tough plant to deal with. It produces horizontal stem rhizomes and deep taproot tubers that make it very hard to eradicate. Each plant can produce 15,000 seeds, ensuring many generations of weeds to fight off.

What It Looks Like: Creeping Bellflower has a greenish-purple stem that can reach up to 3ft high. The leaves are deep green, 4 inches long, and heart-shaped. They get rounder and small the higher up the stem the leaves grow. The flowers are bell-shaped and grow off the end of each stalk. These 5-lobed flowers have a deep blue color and bloom from June to October.

How to Get Rid of It: This is a highly invasive species and should be removed right away. You need to know how to get rid of these blue flowers on your lawn. Mowing and cutting back can weaken a mature plant, but will not eliminate it. To kill this lawn weed, you will need to use herbicide with glyphosate or dicamba. To remove the plant, dig down at least 6 inches and remove all of the tubers and rhizomes. Completely remove the weed waste and dispose of it away from your yard…do not add it to your compost!