Prickly lettuce is a troublesome weed found in many yards across the United States. It can be identified by its spiny leaves and white flowers. Formally known as Lactuca serriola, this weed goes by many other names, including the compass plant, wild lettuce, and even milk thistle. (This is separate from another plant known as milk thistle, or Silybum marianum.)
You can control prickly lettuce with selective herbicides, but its essential first to identify this weed accurately. Prevention methods are also important to keep this weed from returning to your yard.
There are multiple avenues you can take to get rid of prickly lettuce in your yard. You can use specific herbicides to kill it, but you have to be careful because they might also kill the other plants in your yard. Do-It-Yourself Pest Control has a step-by-step guide for getting rid of prickly lettuce, as well as a list of recommended herbicides below.
Prickly weeds like thistles, burweed, and sandburs can make your yard unpleasant and even dangerous to walk on barefoot. Their sharp spines and burs can cause pain and injury to people, pets, and livestock. While removing them by hand seems logical, their thorns and spines make this difficult and unsafe. Fortunately, there are several effective methods to get rid of prickly weeds and prevent their return.
Identifying Common Prickly Weeds
The first step in managing prickly weeds is to identify what’s growing in your yard. Here are some of the most common culprits:
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Burweed – A low-growing winter annual with sharp burs that emerge in spring. Burs can penetrate skin.
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Sandburs – An annual grassy weed that produces sharp, spiny burs in summer and fall. Burs can cause blisters in mouths of livestock.
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Thistles – Robust biennial weeds with sharp spines on stems and leaves Canadian thistle is an aggressive perennial from rhizome roots,
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Bull thistle – A biennial thistle and noxious weed that forms large, spiny rosettes its first year.
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Black locust – A tree with thorns on its trunk and branches Pods are toxic, An invasive species
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Mesquite – A small, spiny tree with a deep root system. Toxic pods. Highly invasive in pastures.
Manual Removal Methods
Hand pulling – Use thick gloves to grab weeds below burs and pull/twist roots out. Soak soil first to loosen. Works best on small, young weeds.
Weeding tools – Use a shovel, trowel, or hoe to dig out or cut weeds. Scuffle hoes sever roots below surface. Prevent rerooting by removing all parts.
Manual removal works for minor infestations but is impractical for large areas. The roots of perennials like thistles also easily break off and regrow.
Chemical Weed Control
Herbicides – Systemic herbicides applied to leaves or stems translocate to the roots to kill the entire plant and prevent regrowth. Selective herbicides target specific weeds. Non-selective herbicides kill all plant life.
Vinegar – High concentration (20%) vinegar kills weeds and roots through repeated contact application. May require several applications. Avoid contact with desired plants.
Pre-emergents – Prevents germination of seeds. Use in early fall for winter annuals like burweed and spring for summer annuals like sandburs.
Post-emergents – Kills weeds after germination. Target young plants and rosettes for most effective control.
Non-Chemical Weed Control
Flame weeding – Uses a propane torch to heat/kill weeds down to their roots. Repeated use will control regrowth. Avoid use during dry conditions.
Solarization – Heats soil by covering area with clear plastic sheeting for 2-3 summer months. Kills weeds, seeds, and root systems through heat exposure.
Overseeding/fertilizing – Crowd out weeds by establishing thick, healthy lawn grass. Thin lawns are susceptible to weed invasions.
Mulching – Blocks light to prevent weed seed germination and growth. Use 3-4 inches of organic mulch around desired vegetation.
Control Methods for Specific Prickly Weeds
Burweed – Pre-emergent herbicide in early fall. Post-emergent spray during winter.
Sandburs – Pre-emergent herbicide in spring. Post-emergent spray of young plants in summer.
Canadian thistle – Frequent mowing/cutting in early summer. Systemic herbicide in late fall.
Bull thistle – Pre-emergent herbicide on seeds. Post-emergent spray of rosettes.
Black locust – Cut stump herbicide treatment to prevent suckering. Avoid disturbance of roots.
Mesquite – Stem or leaf herbicide spraying method depending on tree size. Cut and herbicide soak.
Preventing Regrowth and Reinfestation
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Conduct frequent monitoring and removal of unwanted seedlings.
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Reseed treated areas with native grasses to prevent recolonization.
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Clean mowing and harvesting equipment to prevent spreading seeds.
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Don’t overgraze pastures or disturb soil unnecessarily.
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Maintain healthy turfgrass through proper mowing, watering, fertilization.
With persistence and repeated application of effective removal methods, you can rid your yard of painful prickly weeds. Pay special attention to prevention so your efforts this season aren’t wasted when the weeds return again next year.
Prickly Lettuce Identification And Inspection
Lactuca serriola, or prickly lettuce, is whats known as a winter annual weed. This means that germination begins at the start of winter and the plant only lives for a single growing season before dying off in fall or spring.
Prickly lettuce grows as a rosette of basal (leaves are grouped from a central point in a circular shape). It can grow 2-7 feet tall and features irregularly lobed leaves with prickly edges that are sharp and sometimes painful to the touch. It gets its name from the fact that it texturally resembles lettuce.
Prickly lettuce flower heads are yellow and resemble small dandelion flowers. This flowering process usually occurs from April through October. A single plant can produce hundreds and, often, thousands of seeds, making it difficult to control once it has taken over an area.
Fortunately, several herbicides are effective at killing prickly lettuce. In addition, manual removal can be effective if done regularly (before the plant has a chance to produce seeds).
Inspecting for prickly lettuce includes looking for the plant in its vegetative and flowering stages. The plant can be identified in its mature stage by its thick, deeply lobed leaves. The leaves are usually dark green in color and have a hairy surface.
The undersides of the leaves are often lighter in color and may have tiny prickles. In its flowering stage, prickly lettuce produces small yellow-ish white flowers that grow in clusters.
Large, sharply-pointed bracts surround these clusters. If you suspect that prickly lettuce is present on your property, it is important to correctly identify and confirm its presence so you can begin a treatment plan. This plant can easily be confused with other similar species, so it is important to get an accurate diagnosis before taking any control measures and applying herbicides.
Prickly Lettuce Selective Herbicide Product Recommendations
Selective herbicides work great on prickly lettuce, but you must be careful not to damage the other plants in your yard. The best way to avoid this is to use a selective herbicide designed explicitly for your type of grass. Weve created the list below with a few of our top selective herbicide recommendations for prickly lettuce control.
Blindside Herbicide: This is a selective herbicide that is perfect for suppressing prickly lettuce in turf, including residential, commercial, and institutional lawns, athletic fields, commercial sod farms, golf courses, and other noncrop sites. It is formulated for select warm-season grasses: St. Augustinegrass, Bermudagrass and hybrids, Centipedegrass, and Zoysiagrass. Cool-Season grasses: Kentucky Bluegrass and Tall Fescue.
Bonide Weed Beater Ultra Concentrate: This is a systemic broadleaf weed killer designed for lawn and turf areas. It works on the inside, all of the way to its roots. As an effective herbicide that you can use in hot or cold weather down to 45 degrees Fahrenheit (7 Celsius), this product will give your yard superior post-emergent control with proven performance.
It works against troublesome weeds such as prickly lettuce, pennywort (dollarweed), dandelion, and white clover. In just hours, you may observe injuries of treated plants; by 7 to 14 days, you’ll see total plant death.
Q4 Plus Turf Herbicide: Q4 Plus Turf Herbicide has a unique blend of four active ingredients that are all powerful in their own right. They come together to give you quick results with an herbicide specifically formulated for cool-season turf areas. It controls yellow nutsedge and crabgrass as well as certain types of grassy weeds like foxtail or other pesky broadleaf plants like prickly lettuce when used correctly.
In some cases, you may need to use a non-selective herbicide. This is usually only necessary if the prickly lettuce has taken over a large area and you need to kill it quickly. Remember that non-selective herbicides will kill all plants, so only use them as a last resort.
One of our recommended non-selective herbicides is listed below.
Alligare Glyphosate 5.4 Herbicide: Glyphosate is a powerful, non-selective herbicide that can kill many plants. Its often applied as a foliar spray to trees and other woody leafy greens. Its also fully capable of taking care of many broadleaf weeds, such as prickly lettuce.
The best way to prevent prickly lettuce from taking over your yard is to regularly inspect your property and remove any plants that are present. This is most effective before seed maturation. Additionally, you can use herbicides as a preventative measure.
THISTLE: The Worst Weed In Your Garden! How To Get Rid Of It And ALL Its Invasive Roots!
FAQ
How do you get rid of spiky weeds?
- Hand Pulling. For individual thorny weeds or small patches, hand pulling can be an effective method. …
- Digging. For thorny weeds with deep taproots, such as burdock, digging is necessary to ensure complete removal. …
- Smothering.
What is the best way to kill prickly weeds?
The most effective ways to kill prickly weeds, like thistles, often involve a combination of strategies. For small infestations, hand-pulling (with gloves!) and digging out the roots is a good first step, followed by targeted herbicide application or mulching to prevent regrowth.
How to get prickly weeds out?
Weeding out young thistles by hand and applying herbicides at the right time of year are most effective for getting rid of this prickly weed. Keeping your grass healthy and lush through proper mowing, watering, and fertilizing is key to preventing thistles from invading your lawn.
What are the prickly weeds in my yard called?
Thistles are a prickly group of invasive weeds known for their stiff, pain-inducing thorns. These broadleaf weeds can be biennial or perennial, living just two years or several years.
How do you remove prickly weeds?
Using a weeding tool is a good option for removing prickly weeds that are too difficult to get rid of by hand. Weeding tools make an easier job of digging or cutting spiny weeds. To remove deep-rooted weeds, you can use a gardening shovel to dig around and under the weed and lift it out of the soil.
What is a prickly lawn weed?
Burr Medic, Goat Head Weed, and Lawn Burweed are low-growing prickly lawn weeds. Spiny Sowthistle and Spiny Cocklebur are high-growing spiky weeds you may see on your lawn that can release painful burrs you may never see. Carolina Horsenettle and Jimson Weed are nightshade relatives and are both weeds with thorns on their stems.
Are prickly weeds bad?
Prickly weeds are among the worst weeds to find in your garden. They’re painful to stand on and brush against. And their sharp spines make weed removal difficult. But it’s important not to let them grow. Because the only thing worse than a prickly weed is a yard full of them. Despite the difficulties, you can get rid of prickly weeds by hand.
Does vinegar kill prickly weed?
Vinegar is a contact herbicide that quickly kills the parts of the weed that you spray it on. To kill the prickly weed above ground, make sure the plant is well soaked. It’s also a good idea to soak the soil with vinegar around the weed. Why? Because if you don’t kill the roots the prickly weed will often grow back.
How do prickly weeds grow?
Prickly weeds have a specific life cycle. They start as seeds in the soil. Next, they sprout into small plants. Then, they grow into mature weeds. These weeds produce more seeds. Finally, the seeds fall to the ground. The cycle begins again. Understanding this cycle helps in controlling them.
How do you kill spiky weeds without touching them?
Another way of killing spiky weeds that doesn’t involve you having to touch them is to cover them with black plastic sheeting. The sheeting prevents sunlight from reaching the weeds, stopping them from photosynthesizing.