Plant vegetables based on weed indicators?

I've been thinking a lot about weeds lately, and watching the grass grow, if you will. I got a lot of useful information from another thread about When to weed and when to let be.

It led me to try to find some resources on using weeds as indicators of soil nutrition. And I found a pretty nice article from almanac.com: https://www.almanac.com/weeds-indicator-plants. I appreciate that it shows pictures and discusses a short list of probable indications.

I am having a hard time finding as simple a chart of particular vegetable needs... but what I really want is to be able to look at a plot of ground, watch it for a year. Note what weeds grow there and based on that make judgements about what crop plants are best suited without any particular soil amendments (where possible). I assume that crop rotation charts are designed with this principle in mind, but without weeds as inputs.

For example, and this is totally fictional because I have no idea, but: "Oh crabgrass huh, better plant some carrots here, they'll do great!."

Is this a pipe dream or just a gardener experience level 99 kind of thing?

I am very skeptical of the whole indicator thing, yes you can see extremes some plants will grow where no others will. But in general other than pH indicators weeds are not going to help you much. couch grass will grow on anything from pure chalk, to sand dunes to soggy bog. (don't grow any root veg with it it grows threw them and ruins them) You may see deficiencies in the weeds, my nettles often show an iron deficiency which with my 8.5pH is not unexpected, however I also have a huge amount of buttercup which is meant to only like acid soil.

A good example I think is the Pineapple weed we have, it grows in the drive, heavily compacted gravel, and there yes it is showing that the soil is compacted and disturbed. However it also grows in the veg beds, it grows 10x the size in the veg beds because it much prefers good loose soil the same as most plants. The reason I can say it does show compaction on the drive is because it is one of very few plants that manage to grow there, whereas in the veg bed it's with every other wild plant in the area.  A "weed" will by choice grow in the best ground possible just like any other however a collection of weeds can give a broad idea of the underlying conditions

The problem with that list is I didn't see any weeds or at list what I would call weeds. It did mention crabgrass which I have never had a problem with.

I feel the title would best be called "What Herbs Tell You." Or what "Medicinal Plants Tell You"

I want to know why I was invaded by Bull thistle and sow thistle this year. I asked in another thread though I didn't see an answer.  I think it was that I used so much vinegar killing the ants which might mean they like acid dirt where mine is usually alkaline.

Skandi Rogers wrote:I am very skeptical of the whole indicator thing, yes you can see extremes some plants will grow where no others will. But in general other than pH indicators weeds are not going to help you much.

A good dose of skepticism! 😊 Thanks.

I guess the kernel of truth might be hard to put to the use I was imagining.

Anne Miller wrote:The problem with that list is I didn't see any weeds or at list what I would call weeds. It did mention crabgrass which I have never had a problem with.

I feel the title would best be called "What Herbs Tell You." Or what "Medicinal Plants Tell You"

I want to know why I was invaded by Bull thistle and sow thistle this year. I asked in another thread though I didn't see an answer.  I think it was that I used so much vinegar killing the ants which might mean they like acid dirt where mine is usually alkaline.

Killing ants is fraught with letting other pests take over.  What type of ants are they?  We have populations of termites here and in the main they remain balanced with the many other colonial species.  Our neighbour over the road did not like the meat ants' nests so used poison to kill the nest out instead of managing their behaviour.  Within 12 months, she had 3 walls and most of the ceiling in her house eaten from the inside out.  Where did the termites go up into the house - you guessed it, where the meat ants had been.

Ants and weeds in the garden are OK if in balance.  If it is useful, as in dandelion it is not a weed but if it comes up and you are not using it then, yes, it is a weed.  Ants similarly, they burrow, remove some insects but on the other hand colonise aphids.  DE will sort the aphids and modify the ants' behaviour.  I have posted elsewhere about crabgrass.  Over time, I have noted as soil changes for better or worse, so do the invasive species - including mankind.  There are not too many people settle on a cliff-face but lots invade prime agricultural areas to chop up into housing blocks and force farmers out to more marginal land to produce the same amount of food who then need more inputs, often not good for the land they are trying to farm and directly afffect downstream by way of pollution and sedimentation.

I love this idea! A chart of weeds as an indicator of x soil conditions so y veg will thrive....
I bet Geoff Lawton and Matt Powers, John Kempf etc have I go on this?

I have found that a sprinkle of used coffee grounds keeps ants out of the house.   They still make hills outside where they don't bother anything.

Tina Gee wrote:I love this idea! A chart of weeds as an indicator of x soil conditions so y veg will thrive....
I bet Geoff Lawton and Matt Powers, John Kempf etc have I go on this?

Awhile back I saw a Geoff Lawton video on this very topic.  Sorry, I don't remember details.  I do remember he talked about what thistles tell you.  Stefan Sobkowiak of Miracle Farms has talked about weeds some.  He has talked about dandelions.
So, you are right about Geoff Lawton.  There is information out there.

I find examining the soil to be more helpful than weed placement. I’ve got broom grass all over five hills, which should indicate acidic soil. But there are 20-30 other grasses, wild flowers and weeds mixed in. The soil is bare in some places between plants. Sandy Loam that has had practically every iota of organic matter washed out of it in the top few inches. There are areas where lush grass carpets the soil - water drains there. Also, 100 year flood plains that exploded this spring after they were flooded last fall. I look for good soil. Planting where there are bare spots around healthy tufts of grass is going to require more amendments. I’m blanketing a parcel of the floodplain in cardboard, smothering all the plants and covering with manure. I can grow practically anything in that and won’t need to add much for a few years.

Since I’m a compost in place, deep sheet mulching guy, I don’t encounter many weeds in my garden. When I do they’re usually at the edges where the interesting things happen. There I bump up against my dislike of “weeds.”  My definition of a weed is a plant I don’t like in a place I don’t want it. So, I get to consider whether that thought is true. The weed’s appearance is really an indicator of a possible prejudice on my part. I may not have truly considered what function this plant could possibly serve in the overall design. Do I pull it and compost it? Do I stomp it into the mulch? Do I let it be and observe what its growth cycle is and possibly learn when and what I can do to include it into the design. So, all that brings me to the question, “What the hell am I going to do about these damn weeds?” but from a PC perspective not a pissed off gardener perspective.  

Oh my! I'm sorry but I can't help not to giggle to myself
If I went by the (ahem)  indication of weeds,  (grass or any other), then my garden's health  would be absolutely beyond fabulous and a # 1 in Guinness record book LOL

To my mind a weed is a weed if you
#1, don't have a use for it (e.g., drying it for tea, poultice, flavoring, eating fresh, bothers you,  is so invasive ).
#2, don't want it.
#3, never use it as an indicator to grow anything else but...weeds (I could be wrong on that one but... my experience never "said" otherwise).

As for those ants ( black, ground nester, usually crawling on peony buds) what worked for me was the mixture of 1:3  (1 part of water to 3 parts of sugar)
1tsp of borax (know as 20 mule team or laundry borax )
3 tsp of regular white sugar (or caster sugar)

2 Options to use:

#1  Enough water to make a paste  
Place the paste in a small  enclosed container with very small openings  in areas/pathways  of where the ants are frequenting.
Reusable dip/sour cream/Philadelphia  etc. containers  with punched out holes work great.  
The container should have removable lid/s  to refresh the paste once a week when placed in full sun, or once every 2 weeks if placed under plants or shaded area/s.
The paste will get hard but ants don't seem to mind BUT, they do seem to lie it fairly fresh.

#2  KEEP AWAY FROM PETS !!!
Same recipe but add a little more water for soaking cotton balls.
Place soaked cotton balls in  areas/pathways where ants are frequenting.

I prefer caster sugar as it dissolves much quicker and hot water (for the same reason) and let the paste cool.
I DO NOT use cotton balls .
The recipe worked great. No ants at the end of Summer, and no ants for the last 3 years.
The recipe can be adjusted as one sees fit (more for more ants).
Thank you

If there are no ants on peony buds, they have a hard time opening….

Another thing weeds will tell you is where in your growing cycle you are.  Some seeds germinate under the snow…

As the soil warms in the spring and summer different sets of seeds germinate on bare soil.

A few seasons of observation and keeping notes, either written or mental or both, and you will know a lot…. I don’t know any pairings and they will vary from one location to the next, and different soil types but for example, you might notice that when the amaranth is germinating on bare soil, you can direct seed various warm season vegetables.

It’s more accurate and location specific than the info on the seed packet, or any generic instructions that are not based on conditions on your place.