15 White Flower Weed Varieties: Identification and Control

If you’re a homeowner or avid gardener like me, you’re already very familiar with the work that goes into a weed-free landscape! 

There are all kinds of unwelcome guests you might find in your lawn or garden, but those with conspicuous flowers stand out particularly well against the greenery. Though nuisance plants can have blooms of almost any color, there are a surprising number of white flower weed varieties.

In this article, I’ll help you identify that white flower weed in your landscape and teach you how to most effectively manage its spread. 

15 Common Weeds with White Flowers

Some weeds are easy to identify based on just a quick glance. Take dandelions for example, which almost every gardener can ID whether the plant is in flower or not. Others require a closer look to positively ID, especially if there are other plants in the region that have similar traits. 

Once you’ve narrowed down the white-flowered weed invading your garden, you can start crafting a strategy for control. This should take into account things like the plant’s life cycle when it’s most active in the landscape, and how it responds to things like chemical herbicides.

And perhaps the most important thing to know about a nuisance weed is how it spreads. This is because you’ll want to tackle a weed that spreads solely by seed much differently than one that utilizes vegetative methods like rhizomes or stolons.

1. White Clover

White Clover

Trifolium repens

  • AKA: Dutch Clover
  • Lifecycle: Perennial
  • Origin: Europe, Asia

White clover is a low-growing perennial commonly found in lawns, garden beds, and other disturbed areas. Despite its weedy reputation, white clover has recently gained popularity as an alternative to traditional turf grass.

This weed is easy to identify thanks to its trifoliate leaves and white (sometimes pink) flowers. Blooming usually starts in early summer and lasts until fall.

White clover spreads via horizontal stems (called stolons) that put out new roots and shoots as they grow. This often results in patches of clover covering large sections of soil. It can also reproduce using seeds.

You can control this weed by pulling or digging out less-established colonies and mowing down flowers before they go to seed. Most broadleaf herbicides are effective on white clover but should only be used as a last resort.

2. Queen Anne’s Lace

Queen Anne’s Lace

Daucus carota

  • AKA: Wild Carrot, Bishop’s Lace
  • Lifecycle: Biennial
  • Origin: Europe, Asia

Queen Anne’s lace is commonly found growing in dry fields and roadside ditches. It has a biennial lifecycle and does not flower until its second (and final) growing season.

You may also know this weed as a wild carrot. That’s because Queen Anne’s lace is the plant our cultivated garden carrots were derived from. 

While 100% edible, Queen Anne’s lace is best left alone because it closely resembles incredibly toxic weeds like poison hemlock. Only very experienced foragers should harvest this plant.

Removing flowerheads before they go to seed is generally the simplest method of control. Note that, though non-native, many insects rely on Queen Anne’s lace as a food source, including the black swallowtail caterpillar.

3. Poison Hemlock

Poison Hemlock

Conium maculatum

  • AKA: Wild Hemlock
  • Lifecycle: Biennial
  • Origin: Europe, Africa

Poison hemlock and Queen Anne’s lace look so alike that most people opt to give both a wide berth just to be safe. The former is very toxic if ingested by humans or animals, and can cause severe skin reactions in sensitive individuals when touched.

If you must differentiate between poison hemlock and its look-a-likes, the best strategy is to check the stems for purple mottling. According to the National Park Service, the harmless Queen Anne’s lace and true wild parsnip (Pastinaca sativa) do not have this colouring.

4. Hogweed

Hogweed

Heracleum spp.

  • AKA: Wild Parsnip, Cow Parsnip
  • Lifecycle: Biennial or perennial
  • Origin: Eastern Europe, Western Asia

Hogweeds are a genus of nasty weeds closely related to crops like parsley and carrot. Most species are native to the Caucasus Region of Europe and Asia. Cow parsnip (H. maximum) is the only hogweed species native to North America.

Giant hogweed (H. mantegazzianum) is the most notorious of all hogweeds. This plant can grow up to 15 feet tall and produces an irritating sap that causes skin reactions including blisters, burns, and long-term scarring.

Physical control methods are the safest for surrounding vegetation and wildlife. However, many hogweed plants grow too large to be easily dug up and may regrow if part of the root is left behind.

Broad-spectrum herbicides like glyphosate are also quite effective on hogweed when used correctly. Regardless of the control method, be sure to remove flowerheads to prevent seed dispersal.

5. Chickweed

Chickweed

Stellaria media

  • AKA: Birdweed, Chickenwort
  • Lifecycle: Annual
  • Origin: Europe, Asia, Africa

Chickweed is a common cool-season annual you might find in lawns, garden beds, and pastures. It also likes to invade potted plants kept outdoors.

Chickweed has a low-growing, or prostrate, habit. Plants can branch out from a central rooting point, such as a crack in a walkway, and cover large sections of the surrounding area.

While chickweed isn’t classified as a noxious weed, it’s still problematic because of how easily it spreads via seed. Pre-emergent herbicides are quite effective when applied at the right time of year.

6. Daisy Fleabane

Daisy Fleabane

Erigeron annuus

  • AKA: Annual Fleabane
  • Lifecycle: Perennial
  • Origin: North America, Central America

At first glance, daisy fleabane is attractive enough to pass as an ornamental landscape plant. The problem with this weed is its tendency to pop up anywhere there’s bare soil. It self-sows incredibly well and won’t take long to spread into areas you’d rather it not.

I prefer to hand-pull daisy fleabane early in the season (before it seeds) when I find it in my garden beds or anywhere else it doesn’t belong. More serious infestations can be easily controlled with broadleaf herbicides.

This is one of those ‘weeds’ that, depending on your geographic location, might be okay to let grow in more naturalized areas. Many pollinators enjoy the flowers and foragers like rabbits and deer will happily eat young foliage.

7. Hairy Bittercress

Hairy Bittercress

Cardamine hirsuta

  • Lifecycle: Annual or biennial
  • Origin: Europe, Asia

In my experience, hairy bittercress is another weed that will expertly find and take root in even the smallest of crevices. The good news is that it has very shallow roots and comes out of the soil like butter when hand-pulled (especially after a bit of rain!).

Hairy bittercress leaves are somewhat heart-shaped. They may be confused for something like clover or wild violets without a closer look. Once the small white flowers emerge above the foliage, however, this weed is pretty unmistakable.

Hairy bittercress seeds germinate in the fall and overwinter before sprouting in the spring. Pre-emergent products must be applied in late summer to be effective on this weed.

8. Jimson Weed

Jimson Weed

Datura stramonium

  • AKA: Thorn Apple, Devil’s Snare, Jamestown Weed
  • Lifecycle: Annual or perennial
  • Origin: Central America, South America

If I was going to design a Halloween-inspired landscape, I think Jimson weed would be a must-grow. Of course, there’s little chance of me planting this poisonous weed on purpose!

Jimson weed belongs to the infamous nightshade family, which also includes popular crops like tomatoes and eggplants. According to West Virginia University, there are several historical cases of Jimson weed extracts being used to treat injuries and induce hallucinations.

Aside from being invasive, jimson weed is a problem throughout North America because it poisons livestock that eats it. It is toxic even after being dried, such as when hay bales are contaminated with the plant.

9. White Nettle

White Nettle

Lamium album

  • AKA: White Dead-nettle
  • Lifecycle: Perennial
  • Origin: Europe, Asia

White nettle looks very similar to stinging nettle but lacks the potent skin irritants of the latter. It is very common in recently disturbed areas and boasts hooded white flowers during cool weather from spring to fall. 

This weed doesn’t pose many ecological problems. Most gardeners that choose to remove it do so because they don’t like the look of it in their lawns or garden beds.

Mowing white nettle before it goes to seed in late spring is an effective strategy of control. You can also apply a pre-emergent herbicide in the fall to prevent the sprouting of new seeds.

10. Lesser Quickweed

Lesser Quickweed

Galinsoga parviflora

  • AKA: Gallant Soldier
  • Lifecycle: Annual
  • Origin: Central America

Lesser chickweed is a nuisance weed in vegetable gardens and ornamental landscapes. It’s hard to control since it self-sows very readily and can complete several life cycles within a single growing season.

From a distance, the flowers of lesser chickweed may appear yellow. But a closer look reveals small white petals surrounding a yellow centre.

The best way to control this weed in the lawn and garden is to stop it from flowering and releasing seeds. If lesser chickweed is a known problem in your area, basic cultural practices like mulching can also prevent infestation.

11. Multiflora Rose

Multiflora Rose

Rosa multiflora

  • AKA: Baby Rose, Japanese Rose
  • Lifecycle: Perennial
  • Origin: Eastern Asia

It pains me a bit to include a rose species on this list. Yet there’s no denying the damage multiflora roses have done to a number of North American habitats.

These roses were introduced in the 1800s and remained super popular until almost the end of the 20th century. Today, however, we know that they spread incredibly fast via seeds and can choke out native plant species in uncultivated areas.

According to the Ecological Landscaping Alliance, you can manage multiflora roses from invading the landscape by digging up or cutting back plants before they flower. These shrubs are vigorous growers, so you may need to cut back new growth several times during the year to prevent flowering.

12. Stinking Chamomile

Stinking Chamomile

Anthemis cotula

  • AKA: Mayweed, Dogfennel, Stinkweed
  • Lifecycle: Annual
  • Origin: Mediterranean 

Stinking chamomile gets its common name from the distinct, semi-foul odor it gives off. It can be found all over the world in disturbed meadows, livestock pastures, and crop fields.

This weed is problematic largely because of its allelopathic properties. Allelopathic plants prevent other plants from growing in the surrounding soil and can throw a big wrench in any edible garden or agricultural setup. 

13. Whitetop

Whitetop

Lepidium draba

  • AKA: Hoary Cress, Peppergrass
  • Lifecycle: Perennial
  • Origin: Europe, Asia 

Whitetop is a pervasive perennial weed that prefers moist areas like riverbanks and marshes. According to the USDA Forest Service, it is found on all continents except Antarctica. Whitetop is classified as invasive in many of the regions in which it grows.

This weed readily propagates via seed and underground stems. Once introduced, whitetop can cause significant damage to natural habitats as it chokes out native species and creates large, dense colonies.

You need to be careful when removing whitetop plants as they will resprout if any part of the root system remains in the ground. The best course of action is to cut back flower stalks before they can produce seeds while working to kill off the rest of the plant using herbicides or physical methods.

14. Hoary Alyssum

Hoary Alyssum

Berteroa incana

  • AKA: Hoary Madwort
  • Lifecycle: Biennial
  • Origin: Europe, Asia 

Hoary Alyssum is incredibly toxic to livestock, especially horses, and is commonly found growing in meadows and pastures. This weed thrives in dry, low-quality soils where other plants struggle to grow.

Hoary alyssum grows up to 3 feet tall and features clusters of white flowers atop tall stalks. The stems and foliage are grey-green and hairy.

It’s important to monitor for hoary alyssum anywhere animals typically graze. Plants can be successfully controlled by hand-pulling and mowing before the flowers go to seed.

15. Garlic Mustard

 Garlic Mustard

Alliaria petiolata

  • AKA: Hedge Garlic
  • Lifecycle: Biennial
  • Origin: Europe, Asia 

Garlic mustard is one of the most troublesome white-flowered weeds in terms of native habitat health. You also shouldn’t let it take up residence anywhere in your lawn or garden.

There are a couple of reasons why garlic mustard is such a nuisance. The first is that it emerges very early in the spring and shades out native plant seedlings. The second is that its roots release allelopathic compounds that interfere with nearby plant growth.

Hand-pulling is very effective but it can take a few years to completely rid an area of garlic mustard. Pull the plants before they set seed to prevent further spread.

For more articles about flowering weeds, here’s a link to Weeds with Yellow Flowers that may be of interest.

Citations

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Ben's horticultural interest grew when graduating from Hertfordshire University in 1997. Having contributed to numerous publications including Better Homes & Gardens, Garden Design Magazine, and The English Garden. He is also the author of Propagating Houseplants Made Easy.