Weeds indicate soil quality

LaurieLovesLearning

I am curious what you know about what weeds indicate for soil conditions, & what it indicates for nutrients, whether lacking or abundant. If there is stinging nettle, for example, it should indicate rich & acidic soil, but also dampness in the soil.

What can you name for me? Here are a few weeds to kickstart the thought process:

Chickweed

Dock

Lambs Quarters

Queen Anne's Lace

Mullein

Dandelion

Ferns

Wood Sorrel

More?

Michelle D

I know that dandelion doesn't like compost much. It grows better in soil that isn't rich in organic matter. That is part of why it is so common to grow in people lawns.

From experience here in my yard I have noticed that lambs quarters is the opposite. It likes to grow in the areas that we don't clear leaves in the fall and just let them compost where they fall.

Linda Bittle

Horsetail?

LaurieLovesLearning

@Michelle D Dandelion also likes compacted soil & dryer soil conditions. I don't remember what it indicates for nutrients, whether lacking or abundant.

@Linda Bittle Do you know what conditions horsetail enjoys or what it indicates about nutrients or lack thereof?

Michelle D

https://community.thegrownetwork.com/discussion/comment/923820#Comment_923820

If I remember correctly dandelion indicates high phosphates and nitrogen.

vickeym

https://community.thegrownetwork.com/discussion/comment/923820#Comment_923820

@LaurieLovesLearning , I don't know specifics on horse tail, but in my friend's yard... They have a wooded lot, most of it barely touched or not at all. Just cut a driveway through the woods, there is loads of horsetail at least half way up both sides of the drive. Mostly shady, I think it stays fairly damp along there, the driveway does if there is any rain or with breakup, etc.

Michelle D

What @vickeym said about horsetail makes a lot of sense. The few times I have come across it in nature in my area it has always been in a shady damp area that doesn't get a lot of human interaction.

LaurieLovesLearning

@Michelle D Yet we have it in full sun, on the edge of a gravel road, but it cam get a bit damp there at times.

Very interesting.

I hope more people chime in with their knowledge & observations. I was hoping for this to be an exercise to make our brains work a little bit (or a lot), and explore this fascinating world of plant indicators together.

Full disclosure: I watched a video on this. It appeared to be AI produced, even though the channel owner claimed it was all human done. Considering this, I felt that it was better not to post the link, but see what could be discovered & confirmed by our confirmed real, human members. 😀

Torey

I, too, have seen horsetail growing in a wide variety of soils, from gravel at the side of the road in full sun, to wet, boggy soil in both sun and shade. It may depend on the variety. In my area, E. hymale seems to prefer the edge of rivers or creeks where it may be under water during spring runoff but the rest of the time, it exists on very dry sand or gravel. E. palustre is one that prefers marshes; I've never seen it anywhere else.

Lamb's quarters pop up almost everywhere but have the most prolific growth with rich soil high in nitrogen.

Chickweed certainly does best in shaded locations with a rich, moist soil. But it doesn't need that much shade. Taller plants nearby will usually provide enough shade.

Mullein is another that may pop up anywhere but the largest spread I see regularly is in dry, gravelly waste soils in full. In my area that means quite alkaline. They don't seem to require much in the way of nitrogen or humussy soil.

Dock is often seen here in hayfields, where they are usually only being fertilized by cattle. But it is also widespread, likely by cattle, in open range areas, including dry, gravelly roadsides.

Here, ferns are more limited to the acidic soils surrounding the bigger lakes in the Interior Cedar Hemlock zone, with lots of shade and dampness.

Linda Bittle

I recall harvesting horsetail at Wilderness Awareness School with John Gallagher. I recall that it helps remove heavy metals from the soil, and we often found it in ditches that remained wet.

If I remember correctly, there's a resource on the plant in the dentistry class here, too.

Here's some info.

How to Grow and Care for Horsetail (thespruce.com)

How to Detox From Heavy Metals (And Avoid Them in The First Place) (annmariegianni.com)

vickeym

We bought some compost when we lived at our last place. It turned half our place into lambs quarter. I was not happy, back then

I thought it was just a weed. Here where we are now, we had a large pile of mostly clay we had piled up while putting in a driveway. The next year it was covered in lambs quarter. Full sun. After we butchered our turkey a few years ago it took over their run area. Also full sun, but had been mostly gravel with a little clay. We added bedding material of sawdust, leaves and such. Nothing farmed.

Our soil here tends to be acidic. Have not found chickweed or nettle growing on my property though I know folks who complain about it taking over their places.

VermontCathy

I know that some weeds love to grow in disturbed soil. You won't seem them in unplowed grassy fields or most lawns, but as soon as you turn the soil with a plow or tiller, they spring up. Some are good nitrogen fixers, so this isn't a bad thing, but you have to keep them from taking over your crops.

Unfortunately humans have developed crop varieties that are tastier than most weeds and produce more food value, but they are unable to compete with the wild weeds (some of which are the ancestors of the human crop).

Torey

I have been looking for Grindelia to harvest. Its native to this region but so far, the only place I have seen it is in the gravel at the side of roads or in waste locations that aren't clean enough to harvest. Just like many weeds, its quite prolific in some locations but just doesn't seem to spread beyond the shoulder of the road. Very odd, that a native plant would appear to have weedy characteristics.

Chicory (not native here) is another that seems to prefer to grow right beside the road. Rarely in hay fields.

LaurieLovesLearning

I have never seen it in our region, yet it is supposed to be native here. Our conditions would lend well to it (we are actually above an old gravel pit).

Upon further reading, and considering how small our pasture is, and that in drought conditions it can spread easily in pastured areas, is not palatable to livestock and can absorb selenium (which can poison certain livestock), I think I will have to just keep my eyes open.

Lisa K

My French dandelion likes a more moist soil than the wild dandelion that comes up in my yard (even when I do not water).

Torey

@LaurieLovesLearning I wonder if it needs selenium and its not spreading here because it is only getting selenium at the roadside? Our pasture lands for the most part are deficient in selenium and shots are often given for calves, lambs & kids.

It certainly wouldn't be palatable to livestock! For anyone unfamiliar with grindelia, it is similar to knapweed (an extremely invasive, noxious weed here) with the little thistle-like bulb underneath the flower head and it's covered with a very sticky, milky resin.

I want to make grindelia honey with it for a cough syrup.

You can see how easily it should spread on animals with those little hooks on the head.

LaurieLovesLearning

That could be. Sheep were popular livestock to keep here many years ago.

We have selenium in our soil. We were told that selenium poisoning is most likely the thing that caused our llamas to die. Considering, I guess I really don't want to plant it here then.

kbmbillups1

What about chamberbitter? I have been trying to get rid of this mimosa weed. I've been pulling it out before the seeds fall off. I don't want to use weed killer in my garden or at all.

https://hgic.clemson.edu/factsheet/chamberbitter/

Torey

@kbmbillups1 I've never heard of this plant before but not surprising as it is tropical or sub-tropical so its definitely not going to grow in my area.

It seems that it is quite useful from a medicinal perspective. As one of the best ways to control this plant is to pull it before it seeds, then harvest it and use it. It seems to like a neutral soil, nothing too extreme either way so maybe applications of vinegar to the plants if you really want to kill it?

We had knapweed in our yard when we first moved here but after about 3 years of diligently pulling up every plant we saw, we no longer have any.

@LaurieLovesLearning I guess selenium is one of those minerals that has to be in precise balance. I didn't realize that too much could be dangerous. I only knew about the lack of it causing white muscle disease.

LaurieLovesLearning

@kbmbillups1 I have some thoughts for you to consider.

You could always research what might be planted to try to overpower it. I was just commenting yesterday on how we used to have large stands of stinging nettle in low areas of our pasture. The cows grazed it completely, and so now have thick leafy spurge areas, which is certainly not good for most animals to eat. Nettles would have been my (and obviously, their) preferred weed.

There can be cycles of weeds as any other uncultivated plants. When conditions change, they change. Conventional farmers see this with no-till. They now have worse weeds to try to eradicate that had never been an issue before. They changed their method of farming, which led to this change. So, the conditions that changed in your case could potentially be the soil composition, a change in gardening method, or a competition issue.

Fall rye will suppress weeds. That might be a good thing to try (if you can) to use as a cover crop. It may both help with this weed and help build the soil. I'm not sure how long the weed suppression trait remains. That would have to be something you'd need to look into further if that's something you wished to try.

Do you know if this plant spreads by seed, rhizome, runner, root or other means? I know tansy seeds can sit dormant for up to 15 years! Leafy spurge & wild oats have a similar ability to do this as well and will show when conditions are optimal for germination. This is also something to consider.