We would like to help you identify weeds that you find around the county. If you see a weed that you would like identified please upload your photo below and include any details associated with the plant. It is especially helpful to add a common object to the photo for scale and try to include as many details as possible (location landmarks, size of the plant, size of the infestation, time of year, time of day photo was taken, height etc.) We will try to identify the plant and if you would like, help with management recommendations.

Before submitting, scroll down and review past submissions to make sure your weed hasn't already been identified.

Files must be less than 2 MB.
Allowed file types: gif jpg jpeg png.
Enter the response and it will show up on the page.

Past Submissions and Responses

Click an image to enlarge.

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That is a cutleaf nightshade. It is an annual. It contains toxic alkaloids.

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That is kochia. It's an annual weed that spreads by seed.

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That is bindweed. Hard to get rid of in grass. Here's an article from CSU Extension on how to deal with it.

https://planttalk.colostate.edu/topics/lawns/1552-bindweed-control-lawns/

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This is Kochia - it's an annual in the goosefoot family.

That's prostrate spurge. It's an annual weed. If you pull/dig it, try to get the roots, they are pretty easy to pull. If you want to spray it, you can use Round Up

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That is kochia. If you can mow or cut it down before it goes to seed it will reduce the spread. It's an annual & spreads by seed. If you want to spray with herbicides you must do it when its about 5" tall or herbicide is not effective.

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That looks like kochia growing in the grass.

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Wondering what this is. It is in the garden 4' tall.

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That is a prostrate spurge. It likes moisture. It's an annual. Most lawn care products that take care of weeds will get rid of this. Otherwise, you can pull it and make sure you get the roots.

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If you can pull it out, do so. If it goes to seed, those seeds will germinate in your lawn, so your mowing is helping.
If you do not treat your lawn each year with weed & feed products, I'd start there. Once the turfgrass is healthy and growing well it should choke out the kochia and other weeds.

If you can find an herbicide with Fluroxpyr in it that will work. You'll have to make sure it is labeled for use on turf.

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It's one of two weeds - if it's somewhat like a succulent (fleshy leaves/stem) it's common purslane. If the leaves are flat with tiny red spots it's spotted spurge.
Both these weeds are growing now in turf and garden areas. If you are pulling try to get the roots. They are both annuals.
I couldn't enlarge the photo enough but sure it's one of the two.

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This looks like something in the nightshade family and I'd pull it out of your garden.

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That is yellow sweetclover. It's not a noxious weed.

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This looks like lambsquarters.

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That is kochia. You can keep mowing it down or apply an herbicide that contains Fluroxypyr.

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Cathy Fromme Prairie

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What are these?

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These are weeds.

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This looks like an aspen tree sucker, coming up from the roots of the tree.. Maybe send it off the CSU extension to ID. We are good with weeds but the Extension office can probably be a better help to you esecially if you have it in turf..

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This is Purple Groundcherry. It's a native perennial in the nightshade family.

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That is yellow alyssum. It's an annual and spreads by seed. The plant has already flowered and those are seed pods. It flowers early and flowers are yellow. It's too late to spray now as it's gone to seed and will be dying out soon. You can look for it again next year and use Telar with a surfactant.

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Very small fruits approximately 0.3 mm to 0.6 mm
Total plant length 10 to 25 cm

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Yes, this is a weed. It's Yellow Salsify. It's a biennial in the sunflower family.

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That is Miners Candle, which is a native plant. You may consider keeping it. I'm not sure Milestone will kill it, I'm more likely to recommend 2,4-D with Dicamba.

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The leaf looks like a "mallow" - here's a photo of Alkali Mallow - gets a white flower
http://ptrpest.com/weed/malvella_leprosa/malvella_leprosa.html

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This sure looks like cheat grass which is an annual so it'd be easy to pull.

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That weed is Houndstongue. You should get rid of it. You can dig it fairly easily. The seeds are velcro-like and attach to clothing & animals and are very difficult to remove.
If you'd like to use an herbicide 2,4-D will work.

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This is Musineon, a native in the parsley family. Here's some more info about it.
http://www.easterncoloradowildflowers.com/Musineon_divaricatum.htm

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That looks like Kochia. You would need to use something like Vista (fluroxypyr) on it as it is resistant to 2,4-D .

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That is Flixweed. You can use Telar or Escort on Flixweed and it's safe to use on the hay.

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That is yellow alyssum. It's an annual in the mustard family.

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That weed is Hoary Cress, also known as "white top". It's a creeping perennial in the mustard family. It's a list B weed in Colorado and is required to be eradicated.
You can use an herbicide called "escort" to get rid of it. It must be applied at the flowering stage. Mowing repeatedly during the growing season if not using an herbicide to control in
spring/summer timeframe will help.

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That is Canada thistle. If you can dig them out of your lawn do so. Try and get the root. They are easier to pull/dig after rain or watering. The seeds may have blown in from the fields.
There are not many herbicides for turf that will kill thistle.

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This is a weed. Curly Dock.

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We think this is cheat grass. We do have an herbicide called Plateau that is a pre-emergent. You have to put it down in late summer, It would not work on the cheat grass at this point.
I sell Plateau here at our office. If you need more info, let me know.

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That weed is "catchweed" and it's in the Borage family. Catchweed was rampant last year because of all the moisture. It could be the same this year.

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This is Kochia. Kochia is a hard weed to control. thing to grow back. You can manage it by tilling or hand pulling if feasible. Mowing will only make it grow back stronger.

We have an herbicide called E-2 which is a 2-4,D Dicamba mixture with flouroxpyr that works well on Kochia. It has become resistant to many herbicides over the years. If you want to discuss herbicides, call me at the office 970-498-5768.

Puncturevine or "goatheads" are annual weeds and you can get some control by digging and pulling. You really need to do this before any seeds set. The best herbicide to use is Telar,(Chlorsulfuron) it has soil residual activity which will provide season long control as this weed has multiple flushes during the growing season. Telar is not recommended for turf.

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I believe this is broom snakeweed. Its Native to Colorado. It's not on any noxious weeds lists but it can be invasive. If you wanted to spray it with an herbicide, we'd recommend something like Milestone.

https://extension.usu.edu/rangeplants/shrubs-and-trees/Broom_Snakeweed.



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This is Alfalfa. It is cultivated as an important forage crop. It is used for grazing, hay, and silage, as well as a green manure and cover crop. A 2,4-D w/Dicamba herbicide should get rid of it.

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That is Canada thistle - it seems to have a "gall" on the end. You do not want more of this. I do not think this would prevent the knapweed from flowering.

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Yes, it's in the nightshade family. I believe its Hairy Nighshade, which is an annual. The plant grows in cultivated fields as well as waste areas.

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Yes, it's a Tree of Heaven. Its rapid growth also means it can crowd out nearby native plant species, and its aggressive root system can cause damage to pavement, sewers and building foundations. Tree-of-Heaven has an even number of leaflets on each leaf while smooth sumac has a single leaflet at the end of the leaf. The leaflets are distinctive. Smooth sumac leaflets are serrated along the entire margin. Tree-of-Heaven leaflets have one or two “glandular teeth” at the base of the leaf.

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That weed is "prostrate spurge". It's actually easy to pull - you'd want to make sure you get the roots. Its an annual so it grows by seed.
If you want to use roundup that will work on it, but it will also kill any other plant it touches. I believe there is a lot of it this year because of all
the moisture we've had.

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This is field bindweed.
Field bindweed is a non-native deep-rooted perennial that reproduces from seed and creeping, horizontal roots (rhizomes). Field bindweed stems are prostrate (grows low to the ground) and twining, and grow up to 6 feet long. Leaves are distinguishable by their arrowhead shape. The flowers are bell or trumpet-shaped, white to pink in color, and are about 1 inch long. Field Bindweed seeds can remain viable in the soil for up to 40 years.

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This is common mallow. You should pull it now while it's small. As it grows, the roots become very hard to remove. There's nothing you can spray on it that won't harm the new grass at this point.

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This is cutleaf nightshade which is an annual plant.

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This looks like cheatgrass. Not positive since its dead. If you can send a photo earlier in the year with the seed heads we can ID it for sure.
We have an herbicide here called Plateau that can be put down in August (late summer) as a pre-emergent if it is cheatgrass..



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Hi Jean,
we are not turf experts here, but this looks like crabgrass or goosegrass. You can get more info by contacting the CSU extension office.
Here is a video that you may find helpful -
https://www.youtube.com/watch?v=HT0ugchDQ8U

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This has been identified as Pursh Povertyweed. Its a native plant. Since its in the aster family, milestone herbicide should take care of it.

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This is Catchweed. Here's some more info on it. This seems to be rampant this year from all the moisture we've received.

http://www.idahoweedawareness.net/wow/02_02_15.html

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This is flixweed, a winter annual in the mustard family.

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This is Flixweed, a winter annual in the mustard family.

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This is not houndstongue - it actually looks like something from the campanula/bellflower family which is an ornamental

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That is Curly Dock.

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This is Flixweed. Its an annual mustard. Once it flowers it will go to seed and die out. It's pretty abundant this year from all the rain we've had.

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We think this could be Catchweed Bedstraw or sometimes called cleavers. Here's some info on it -

http://ipm.ucanr.edu/PMG/PESTNOTES/pn74154.html

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We think this could be Catchweed Bedstraw or sometimes called cleavers. Here's some info on it -

http://ipm.ucanr.edu/PMG/PESTNOTES/pn74154.html

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Cow parsnip or wild parsnip is similar to the photo of the rosette. These get huge also and can cause quite a bad skin rash.

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This has been identified as Catchweed. Its an annual with rough textured leave & stems with bristly hairs that cling to most anything.

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Tthis is red root pigweed. A 2, 4-D herbicide should work on this.

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This is Canada thistle. Dig it up if possible because it can become very invasive. You may want to consult a turf expect or contact the CSU extension office as they deal more with turf issues than we do.

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There is a creeping bellflower (campanula) that is very invasive. How tall does this get?
I'd think something Like Ortho weed be gone would take care of it - what have you used on it? It kills weeds not the lawn.

(Yes, I think that is it. Looked it up on other sites and it fits my description and experience. Thank you!)

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There is a creeping bellflower (campanula) that is very invasive. How tall does this get?
I'd think something Like Ortho weed be gone would take care of it - what have you used on it? It kills weeds not the lawn.

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Thanks - that is myrtle spurge and its very invasive! Its a noxious weed - I'll have to get someone out to "scout" the neighborhood.

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Yes, Myrtle Spurge. Very invasive noxious weed. We will need to go check the area for more. Thanks!

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That's Hoary Cress - a noxious weed.

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That is a yellow alyssum, or mustard weed. Its an annual weed

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This is definitely a perennial weed but we can't really ID it yet. Once its a bit bigger can you re-submit the photo?
Ir may be field bindweed as the description of the flowers seem to fit.

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Hi - the photos on the right seem to be Prostrate vervain - this is an annual weed. I can email a photo and more info if you'd like. The photos on the left are hard to ID as the sunlight is too bright. Can you re-take and we'll see what we come up with. A better photo of the leaf would help. I'm assuming these are just 2 different weeds. Let me know. Thanks!

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this looks like a choke cherry but I'd check with the CSU extension office website since my expertise is in weeds.
extension.colostate.edu/

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This looks like a choke cherry but I'd check with the CSU extension office website since my expertise is in weeds.
extension.colostate.edu/

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It's not myrtle spurge. This looks like Milkweed. There are many different varieties and I'd guess it is common milkweed or showy milkweed

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That is Myrtle Spurge - you should get rid of it - it's got a milky substance inside the stem that is toxic and can really irritate skin so be careful & wear gloves. It helps if the soil is moist when you dig it up. Try to get the roots. Then re-check each year to make sure it hasn't re-sprouted. Here's a data sheet on the weed.
The other weed at bottom of photo is Musk thistle - also needs to be removed before it spreads. These are both noxious weeds and need to be removed.

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This is field bindweed. There are over the counter products for turf that can help take care of this.

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That is either crab grass or goose grass. We are not turf experts so you should contact the CSU extension office and they may be able to help you out.

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That's prostrate spurge. Most ready to use lawn care products will take care of it. Weed B Gone or something similar, safe to use on lawns. It'v very common in late summer and can really spread. It does pull out easily, but make sure to get the roots.

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This is Buffalobur. It's a native annual.

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That field bindweed - find an herbicide for lawns with Quniclorac in it.

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This is a pigweeed. We have different types of pigweeds in Larimer county but none of it is so invasive that we require property owners to eradicate it. It's not a noxious weed here. I believe a broadleaf weed kill, like 2,4-D Amine or Rangestar (2-4,D amine with dicamba) would work.

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These are "Forget me Nots" or Scorpion Grasses
Scorpion grasses
Myosotis is a genus of flowering plants in the family Boraginaceae. In the northern hemisphere they are colloquially denominated forget-me-nots or Scorpion grasses.
Scientific name: Myosotis
Higher classification: Borages
Rank: Genus

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This is common vetch or hairy vetch. If you can pull or dig it out, making sure you get the roots, that may work. Did you ever try Round Up on it? That may work but you'd have to keep it off the other plants.
If you dig it up , keep checking back for new sprouts and treat them with Round Up. I also read that using an herbicide with tricloypyr in it would get rid of it after several treatments but it may harm the other stuff in the bed so read the label carefully. There are some ready to use products with Tricloypyr at Lowes, Walmart etc.

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That weed is "Flixweed" which is in the mustard family. Its an annual and has a early, short growing season.

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This is Canada thistle.