7 Common Idaho Lawn Weeds (And How to Get Rid of Them for Good)
If you’ve ever looked out at your lawn and wondered, “What is that growing out there?”, you’re not alone. Idaho lawns deal with all kinds of pesky weeds—some that look harmless and others that can really take over fast.
In this blog, we’ll walk you through the most common lawn weeds in our area, how to identify them, and what you can do to send them packing. Because a healthy, beautiful lawn shouldn't have to compete with the weeds.
1. Crabgrass
Crabgrass is one of those weeds that shows up fast and doesn’t play fair. It loves hot, dry conditions and tends to sneak into bare or thin patches of lawn, where it quickly spreads and takes over.
Once established, a single crabgrass plant can drop thousands of seeds, setting the stage for even more to pop up the following season.
What Crabgrass Looks Like
Crabgrass grows low to the ground in a wide, spreading shape. The leaves are pale green and broader at the base, giving it a loose, bunchy look.
By late summer, you might notice finger-like seed heads shooting up from the center — a clear sign it’s matured and ready to multiply.
Why It’s a Problem:
Crabgrass competes aggressively with your lawn’s grass, stealing sunlight, water, and nutrients. Left alone, it can quickly turn a smooth green lawn into a patchy mess.
How to Keep It Out:
- Mow a little higher. Grass that’s cut at 3 inches or taller naturally shades the soil and blocks crabgrass seeds from sprouting.
- Use pre-emergent in spring. Timing is everything. Pre-emergent herbicides work best when applied just as the soil starts to warm — usually when it hits around 55°F.
- Keep your lawn thick and healthy. A dense lawn makes it harder for weeds like crabgrass to get a foothold in the first place.
The key is staying one step ahead. With a little planning, you can keep crabgrass from gaining ground and enjoy a lawn that looks great all summer long.
2. White Clover
White clover might look innocent — with its cute, rounded leaves and tiny white flowers — but don’t let it fool you. Once it finds a spot in your lawn, it tends to stick around.
It spreads low and wide, filling in gaps wherever the grass is thin, and it can be surprisingly tough to get rid of without the right approach.
What White Clover Looks Like
White clover forms dense patches with small, round leaves grouped in threes (yep — like a lucky clover). In late spring and early summer, it blooms with little white flower heads that bees love.
It tends to grow close to the ground, making it easy to miss until it starts spreading.
Why It’s a Problem:
While clover was once included in lawn seed mixes, most homeowners now prefer a clean, uniform grass look — and clover just doesn’t fit the picture.
It grows aggressively, especially in areas where grass is struggling due to low nitrogen, and can make your lawn look spotty or uneven.
How to Keep It Out:
- Fertilize properly. Clover thrives in underfed lawns. A regular lawn fertilization program helps give your grass what it needs — and makes it harder for clover to take hold.
- Spot-treat if needed. Broadleaf weed control products can be effective when applied to clover patches during active growth.
- Improve lawn density. Overseeding and maintaining a thick lawn makes it more difficult for weeds like clover to find an opening.
If you’re seeing patches of clover popping up, it’s a sign your lawn could use a little boost. With the right care, you can send it packing and get your grass back in shape.
3. Canada Thistle
If there’s one weed that really knows how to dig in and stay awhile, it’s Canada thistle.
This one’s a fighter. With a deep, creeping root system and spiny leaves, it can quickly spread across lawns and landscape beds, making itself right at home where it’s not wanted.
What Canada Thistle Looks Like
Canada thistle grows upright with narrow, spiny leaves that have a jagged or toothed edge. In early to mid-summer, it produces clusters of small, purplish flowers at the tops of its stems.
But it’s what’s happening underground that makes it so tricky — its roots can grow several feet deep and send out shoots that sprout new plants all over the yard.
Why It’s a Problem:
This isn’t a weed you can pull and forget. Even a small piece of root left behind can grow into a new plant. Left alone, Canada thistle can spread quickly and choke out your lawn’s grass, competing for water and nutrients.
How to Get Rid of Canada Thistle
- Don’t just pull it. Pulling or cutting alone usually isn’t enough — in fact, it can make things worse by encouraging more underground growth.
- Use a selective herbicide. Targeted weed control applied when the plant is actively growing can help knock it back. Multiple treatments may be needed for full control.
- Maintain healthy turf. A thick, well-fed lawn gives thistle fewer places to start. Consistent care makes a big difference.
When it comes to thistle, persistence pays off. With the right combination of weed control and lawn care, you can stop this spiky intruder from taking over.
4. Dandelions
They might be a childhood favorite for making wishes, but dandelions are a different story when they show up in your lawn.
These bright yellow flowers pop up fast in spring and quickly turn into puffballs ready to spread seeds with every breeze. And once they’ve taken root, they’re tough to evict without a little strategy.
What They Look Like
You’ll spot them easily — sunny yellow blooms rising above a cluster of jagged, dark green leaves.
As the flower matures, it forms a round, white seed head that’s just waiting for a gust of wind (or curious kid) to scatter seeds across the yard.
Why They’re a Problem:
Dandelions are more than just a visual nuisance. They spread quickly, send down deep taproots, and compete with your grass for nutrients and space. Plus, they’re tough — that deep root helps them survive mowing, foot traffic, and dry conditions.
How to Get Rid of Dandelions
- Pull carefully. If you catch them early, you can dig out the root with a weed tool — but you need to get the whole thing, or it’ll grow back.
- Apply broadleaf weed control. Targeted treatments work best when the weed is actively growing (spring or early fall is ideal).
- Feed your lawn regularly. Healthy, thick grass makes it harder for dandelions to move in.
Dandelions may be persistent, but they’re not unstoppable. With a bit of attention and a consistent lawn care routine, you can keep them from coming back year after year.
5. Black Medic
Black medic is one of those sneaky weeds that can blend in with your lawn at first — until it starts spreading. It's often mistaken for clover, thanks to its small, rounded leaves, but it behaves more like a stubborn guest that doesn’t know when to leave.
What Black Medic Looks Like
Black medic has three-leaf clusters that look a lot like clover, but with a slight point at the tip of each leaflet. It grows low to the ground in a sprawling pattern.
One of its most recognizable features is its tiny, bright yellow flower clusters that bloom in spring and summer, eventually turning into small black seed pods.
Why It’s a Problem:
This weed thrives in compacted or underfed soils — the kind of spots where your grass is already struggling. While it doesn’t always take over like crabgrass or dandelions, it spreads fast and can create uneven patches across your lawn.
How to Get Rid of Black Medic
- Improve lawn health. Black medic is often a sign your lawn needs a boost. Aerating compacted soil and following a solid fertilization program can help crowd it out.
- Spot-treat with broadleaf control. Post-emergent herbicides can help knock it back if it’s already made itself at home.
- Mow regularly (but not too short). Keeping your lawn well-maintained gives grass the edge and helps prevent medic from spreading.
If you’re seeing black medic pop up, it’s a signal your lawn may need a little TLC. Get ahead of it with good care, and your grass will win out every time.
6. Field Bindweed
Field bindweed may look delicate with its small, funnel-shaped flowers, but make no mistake — this is one of the most persistent and frustrating weeds Idaho homeowners can face.
It spreads by both seed and underground roots, which means once it’s in your lawn or landscape beds, it doesn’t give up easily.
What It Looks Like
This vine-like weed has slender, trailing stems that twist and tangle through your lawn or wrap around other plants.
Its leaves are shaped like arrowheads, and it blooms with small white or pale pink flowers that resemble mini morning glories.
It tends to creep along the ground or climb up anything it can grab onto.
Why It’s a Problem:
Field bindweed has an incredibly deep and far-reaching root system, which makes it especially hard to control. Even after mowing or pulling, it often regrows from bits of root left behind underground. It competes fiercely with turfgrass and garden plants for moisture, sunlight, and nutrients.
How to Keep It Out:
- Don’t rely on pulling alone. This weed’s roots can extend feet below the surface — hand-pulling is rarely enough.
- Use persistent weed control. Multiple applications of selective herbicides are often needed over time to weaken and control it.
- Thicken up your lawn. Keeping your grass dense and healthy gives bindweed fewer chances to take hold.
Bindweed is stubborn, no doubt about it. But with consistent effort and a strong lawn care routine, you can break the cycle and reclaim your lawn.
7. Common Mallow
Common mallow has a way of showing up in places it doesn’t belong — popping up in lawns, garden beds, and even sidewalk cracks.
With its wide, scalloped leaves and small purple flowers, it might look harmless at first glance. But it’s another weed that’s tougher than it looks.
What It Looks Like
Mallow grows low to the ground with round, crinkled leaves that resemble miniature lily pads. The stems often sprawl out in a circular shape.
In summer, it produces pink or purplish flowers with five petals. As it matures, it develops small, segmented seed pods — sometimes called “cheese wheels” because of their shape.
Why It’s a Problem:
Mallow is a survivor. It thrives in compacted soil and can tolerate drought once it’s established. Its deep taproot helps it hang on through mowing, foot traffic, and dry spells. It can also crowd out desirable grass and plants if left unchecked.
How to Get Rid of Common Mallow
- Catch it early. Young mallow plants are easier to remove by hand — especially before they develop deep roots or go to seed.
- Use post-emergent control. For larger or spreading patches, broadleaf herbicides can be effective with repeated treatment.
- Improve soil and turf health. Aerating and fertilizing helps strengthen your grass, making it harder for mallow to gain a foothold.
While common mallow might not be as flashy as some other lawn invaders, it’s still a problem worth dealing with early. Stay ahead of it, and your lawn will thank you.
How We Tackle Tough Lawn Weeds in Idaho
At Lawn Buddies, our six-step lawn care program is designed to do more than just feed your grass — it helps your lawn fight back against weeds. Each visit includes carefully timed weed control that addresses seasonal challenges and keeps your turf looking great.
Most weeds are taken care of through the standard six visits. But for more persistent troublemakers — like thistle, bindweed, or black medic — we may recommend an additional treatment using a specialized herbicide.
It’s all part of a long-term strategy. Because weed control isn’t a one-and-done deal — it’s a process.
Healthy Lawns Keep Weeds Out
The best way to win the weed war? Keep your grass strong. When your lawn is thick, lush, and well-fed, there’s simply less room for weeds to move in.
That’s why our program includes the right fertilization, watering guidance, and mowing tips to support healthy root growth. Dense turf crowds out weed seeds and blocks the sunlight they need to sprout.
Weak or patchy areas are prime targets for weeds — we help you patch them up and build a lawn that holds its own.
Real Talk About Weed Control
Let’s be honest — even with the best weed control in Idaho, you’ll still see a few weeds now and then. That’s not failure — that’s nature.
Here’s why:
- Some weed seeds lie dormant in the soil for years.
- Wind, pets, birds, and even your shoes carry in new seeds.
- No single herbicide works on every weed.
- Heat and hardscapes (like sidewalks or curbs) can reduce herbicide effectiveness.
We’re here to manage those variables and stay one step ahead — so you don’t have to.
Partner with Lawn Buddies for Weed Control in Idaho
If you're tired of battling weeds on your own, we’re here to help.
Our one-and-done, six-visit lawn care program includes:
- Fertilization
- Weed treatments
- Grub control
- Seasonal timing that works with Idaho’s climate
No confusing packages. No guesswork. Just everything your lawn needs, right on schedule.
Serving homeowners in Idaho Falls, Boise, and surrounding areas, Lawn Buddies makes lawn care easy — and weed control one less thing on your to-do list.
Read to Get Started?
You’ve got a busy life. Let us handle the weeds. Here’s how:
- Fill out the form on this page
- Call us at (208) 656-9131
- Or read more about our services
Then kick back and relax in your healthy, thriving yard.
Image Source: Crabgrass, White Clover, Canada Thistle, Dandelion, Black Medic, Field Bindweed, Common Mallow