Reading 'Weeds' as Indicators of Soil Conditions

Temperate Humid Climates - what's the best resource you have found on reading 'weeds' as indicators of soil conditions? (I am located in the eastern US.)

Several species of which I am already familiar of their indications - dandelion, buttercup, crabgrass, sorrel, sedge, burdock... I would like to see a more comprehensive resource, though, if one exists.

Thank you!

~Rachel

This is an intruigingin topic. I've heard folks mention this, sort of like a side conversation, but this makes so much sense.
Anyways I know very little, but I would like to learn more. So i asked google and came across these two items that looked worthy to share.
https://archive.lib.msu.edu/tic/holen/article/1993jun20.pdf
https://www.motherearthnews.com/organic-gardening/soil-indicators-zmaz87jazgoe

Please keep us posted. We too live in the Eastern states, in the Southern Appalachians.

Newbie observation from Louisville, KY: I find that along with sorrel, one of the first things to pop, especially if I disturb the soil, is clusters of thin wild onion. I would love to know why. Are they just latent and waiting for a nudge or is this a stage of succession...or both?

Hi Sena,

Thanks for the MSU link! The bit about mineral accumulators is helpful. It gives me a few more options for addressing phosphorus and potassium needs. I tend to ferment certain 'weeds' and use them in a diluted state as foliar feeds. I have done that with nettles, yarrow, chamomile, and allium family plants (with very nice results!), but this gives me more 'weeds' to work with.

Thank you!

~Rachel

No problem Rachel!
Comfrey is often grown and used to add calcium to the soil. Any weed tea that's good for us and the garden.

Such an interesting way to observe the land.
Thanks for posting this question

I know that Johnson grass indicates low humus, poor drainage, low phosphorus, and high potassium.

There is little hard science (papers written on indicator plants are few and far between), but there is a good deal of anecdotal evidence, to support the belief that some weeds prefer certain types of soil and growing situations.
Moss, as we all know, can be a good indication of poor drainage, it can also be a sign of compacted soil or low fertility.
So, "reading your weeds" isn't a foolproof way to evaluate your soil, but it can be a useful hint that something's going on below the soil surface.
To find out what the weeds are really telling you, do a soil test to confirm nutrient levels and soil pH.

Redhawk

There’s a weed for every niche. You can get a pretty accurate read by not only looking at the ground and saying “ huh, I have dandelions, I must have soil compaction.”, but then going a step further, and saying: “wow, those dandelions are really taking over, there must be something about my soil that they really like, and there’s another low-calcium lover around... I probably don’t have enough calcium!”

Excellent though Myron, thus you receive an apple. Thanks for contributing! =)

I love this topic but it’s kind of a mystery to me. What are “beneficial weeds” & what are bad weeds? And then there are the nasty ones w nasty thorns! Ouch!
I’m in my 4th year gardening here just south of Asheville NC. Weeds are a constant struggle for me. I’ve used cardboard & woodchips for walkways, some landscape fabric, heavy compost, manure & mulch on beds. It’s better but weeds still take up a lot of my time.
I’d like to do some fermenting fertilizer teas w them. And composting. So far I’ve just been dumping them in our woods.
Keep the info coming folks!

Gaurī Rasp wrote:I love this topic but it’s kind of a mystery to me. What are “beneficial weeds” & what are bad weeds? !

Are there bad weeds?

Most plants have some value as the plant might feed both domestic animals and wildlife.

Or the plant might have medicinal value.

There are two plants that I have that I hate and call them weeds.  One plant, sticky willy, I read many times it makes good tea and there is even a PEP badge bit for growing it.

https://permies.com/wiki/126781/PEP-BB-woodland-straw-cleavers

Sicky Willy aka cleavers is also a soil indicator.

If you have wild blueberries grow and all over your yard and they're healthy looking it's an indication you have acid soil.

I have cleavers! And make tea w them. And wild blackberries & black raspberries. Mullein. Plantain. Elderberry. Nasty Virginia creeper vine. But those nasty ones w the thorns, I don’t know what they’re called but grrrrrrrrr

Anne, cleavers is edible and medicinal. It is recommended for moving your lymph. We have more lymph in our bodies than blood, but we have no organ to move the lymph around. We are supposed to be moving the lymph around, which doesn't happen when we binge Netflix and stare at a computer all day.  I just chop it up like most of my edible weeds and put it in my beans, rice, quinoa, oats, etc.  Even green salad.

John S
PDX OR

Gaurī Rasp wrote:I have cleavers! And make tea w them. And wild blackberries & black raspberries. Mullein. Plantain. Elderberry. Nasty Virginia creeper vine. But those nasty ones w the thorns, I don’t know what they’re called but grrrrrrrrr

There are some identification apps now that may be able to help.  The one I prefer is called Seek and it is affiliated with iNaturalist.  It covers animals as well and can be helpful with identifying insects - friend or something with a lack of predators.  With a smartphone you may then be able to identify your thorny nemesis.

Thanks Derek!
You inspired me to look up the weed, which just got me again! It’s called horsenettle. Ugh!

Hi Rachel,
There is a book called 'When Weeds Talk' by Jay l. McCaman that may help you.

Cj Jones wrote:Newbie observation from Louisville, KY: I find that along with sorrel, one of the first things to pop, especially if I disturb the soil, is clusters of thin wild onion. I would love to know why. Are they just latent and waiting for a nudge or is this a stage of succession...or both?

sorrel and onions can use oxalic acid to overcome ethylene diffusion buildup from soil compaction.

https://www.science.org/doi/10.1126/science.abf3013

Buttercups also go into places of compaction to fluff them up.  

John S
PDX OR