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May 28, 2012 · 3 Comments

Weed of the Week: Prickly Lettuce (and Sow Thistle)

Plants

prickly lettuce

My nemesis

This weed has been driving me nuts all spring. It’s not one I’d seen a lot before this year, then — out of nowhere — it infested large sections of your backyard. Not only did it infest the yard, but I had a tough time figuring out even what it is.

After digging around on a lot of university websites and talking to people who know their weeds, I think it is prickly lettuce (Lactuca serriola). But a couple of people have also identified it as sow thistle (Sonchus arvensis L.), and it is certainly possible that I have some of each. The two weeds look remarkably similar — and they’re both trouble.

Note the spines along the leaf vein. (Click for a larger view)

Both weeds like prairie plantings (we’ve got those nearby) and make forays into home landscapes. Both of them have leaves that look like dandelions and both of them emit a white sap when cut. Prickly lettuce has spines on the back of its leaves (and many of those in my yard also have that), as you can see from the photo, which is why I think that’s what I have. The weeds spread both by seed and by rhizomes!

I also learned that if you have a big deluge of rain (say 2 inches in 12 hours), you can pull prickly lettuce with abandon. It is much easier to pull than dandelions, so last week, in between rain storms, I’ve been pulling the prickly lettuce like crazy. I’ve also added some grass patch to the especially infested areas and will likely be over-seeding this fall. However, I don’t expect this will be my last battle with prickly lettuce, or sow thistle, or whatever it is.

What weeds have you been battling this year?

Related posts:

  1. Weed of the Week: Wild Parsnip We’ve had an early spring this year, and I’ve been...
  2. Weed of the Week: Stinging Nettle My hand is tingling as I type this because yesterday...
  3. When Do “Volunteer” Plants Become Weeds? When do volunteer plants go from being a welcome volunteer...
« A Good Year for Clematis
Growing Lettuce in a Window Box »

Comments

  1. Karen says

    June 1, 2012 at 2:28 am

    Oh, how I hate sow thistle. We’ve been battling it here for years, too. If only the roots weren’t so ‘delicate’ for it annoys me no end when pulling it out to have the flimsy root break off with the gentlest of handling. It is truly amazing how far and how fast the plant colonizes an area. I’d rather pull quack grass any day! Good luck with your battle, and rest assured, you’re not alone.

Trackbacks

  1. Weeding in November | My Northern Garden says:
    November 11, 2012 at 10:51 am

    […] where the grass mysteriously has died over the past year, and it’s very prone to a certain dandelion-like weed. So, that got a good going over as did two shrub and perennial beds where I pulled out thistles, […]

  2. Why Weed in November? says:
    October 6, 2018 at 9:54 pm

    […] where the grass mysteriously has died over the past year, and it’s very prone to a certain dandelion-like weed. So, that got a good going over as did two shrub and perennial beds where I pulled out thistles, […]

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