Super short, perennial ground covers in annual beds

If you are in zone 8 or warmer, perennial peanut (Arachis glabrata) would be worth trying.  It's a super low ground cover, nitrogen fixer, doesn't make peanuts but does have edible yellow flowers.  I would guess that it won't compete too heavily...  I may have to experiment with this in my annual beds.  Just started propagating a bunch of cuttings two days ago.

has anyone experienced using roman chamomile as a cover?

I'm doing an experiment with a patch of black medic in my garden.  I've got a volunteer pumpkin and I'm quite confident those two will be fine.  I've also tried planting pole beans into the black medic, I'm less confident about that, but if they can sprout and quickly get above the carpet, it should work.

Don't you find that black medick gets too tall? it gets over 2ft tall here which will swamp most plants. It's commonly used as a green manure crop and against weeds in conventional ag round these parts. (and grows quite happily in my lawn and graveled areas)

Skandi,
It must depend on the climate. I have mostly gardened in the arid SW, but even when I lived in Colorado, our black medic did not get much over 6 inches tall.

Jason Padvorac wrote:
...But to make a living from growing vegetables, I have to be able to maintain a large area with fairly little work. As much as possible, I have to optimize away from needing to go around with a hoe and clippers. The goal is to arrive at a place where I mostly just plant and harvest. There are people doing that already, but they use tilthers, weed cover, and other stuff like that which I am trying to avoid.

My front gardens are a crazy tangled forest garden packed nearly impenetrable in spots with trees, berry bushes, vines and herbs, etc.
It is incredibly abundant with at least 100 varieties of fruits and herbs but I have to go out with hoe/loppers/clippers plus leather gloves to remove blackberries and other "invasives" if I want to keep what I planted and not have a blackberry grove for a front yard. There are lots of "weeds" that I chop and drop (or harvest) and bless them for showing up but if I want to grow annual vegetables, it ain't happening in those sections of garden.
I have had to build nearly every square foot of soil here so when I am growing my annuals, they are kept weed free with no living ground cover.
To clarify, I adore, encourage and plant ground cover in my perennial areas, which most of my gardens are, but I have several annual beds that are only annuals and well weeded and mulched. I have not had success trying to coax tender annuals to win a battle against powerful perennial neighbors. The second biggest issue after crowding is water needs.
I have planted bigger annuals like squash in the forest garden and they did okay but they needed watering and I am keeping my forest gardens very low water so that is another issue. I don't want to be dragging a hose or hauling buckets all over the place when I can keep my wimpy water needy annuals in targeted areas.
Just my 2c and experience.
Here is a pic of my forest jungle:

And here is one of my salad beds earlier this spring, kinda Charles Dowding style. I don't use a lot of mulch on salad greens because we have so many slugs but other annuals like tomatoes and such get a deep mulch.
I realized re-reading this thread that I had recommended strawberries a few years back and they're still doing their thing in perennial beds, but it's too much trouble and work having them with annuals. I'm still learning...and for me it's just less work to not have a living mulch in annual beds.

Skandi Rogers wrote:Don't you find that black medick gets too tall? it gets over 2ft tall here which will swamp most plants. It's commonly used as a green manure crop and against weeds in conventional ag round these parts. (and grows quite happily in my lawn and graveled areas)

The Wiki tells me that Medicago lupulina, commonly known as black medick can grow 6" to 31", so yes, it can grow too tall to be a good companion for our veggies, even though it is a legume.
The Wisconsin Gardener tells us that "Black medic can be an indication of low soil nitrogen in lawns as it outcompetes weak grass. Since we try to have richer soil in our gardens, it might grow much better there, starts prostrate but then stands erect. It is good that it is a legume though, and if the soil is not very rich, it could improve it.

https://en.wikipedia.org/wiki/Companion_planting
https://en.wikipedia.org/wiki/Weed

All depends on your view as to what a plant is ,look out over a meadow all plants grow in community with each other .
you have some plants that are bigger stronger and some that are weak and scroungy.
they all produce their product for there purpose .
then we come along and breed a plant to fit our purpose and it wont produce as well if grown in with other strong plants.

you have to plant things that will out compete your (weed) ground cover.
or be a companion to your plant.
and maybe sacrifice or enhance some production .
   
I have planted things all together some years they do good some they don't.

which brings  up the three sisters garden most that try this don't understand that it works because the mounds that were planted were enhanced with fish,sticks,charcoal,leaves,weeds,they gathered up surrounding fodder and put under the mound.
and the plants that they planted were stronger than what we plant to day because they were closer to the original plant that competed to live.
and they were companion to each other,benefiting from each other.
corn by providing something to climb
beans by nitrogen
squash by ground cover .
and a lot of other things that we haven't even began to understand  

I don't know that you will find something that will work with all plants you might find something that will work with a certain plant.
I plant a row garden because it is the easiest for me to do and i let some weeds alone after it is established .    
I have a terrible problem with sedge grass,crab grass annual beds with enhanced nutrients arn't an option .

I keep wood sorrel growing in my raised beds and pots.  It never seems to get more than 3-4" tall, it's edible, and it happily takes care of itself.  It came in on a single plant  from a greenhouse once and has made itself a home in every last container since.  I have no qualms with it.

I remember eric toensmeier saying he uses violets as low groundcovers around his edibles. Now that I think of it i might start using australian native violets in my garden :)

Ben Schiavi wrote:I remember eric toensmeier saying he uses violets as low groundcovers around his edibles. Now that I think of it i might start using australian native violets in my garden :)

Anything with flowers has the other advantage of bringing in pollinators, so way to go, Ben!
I planted a tray of bright yellow violas and they are now everywhere. I wish they would grow in the beds: they have invaded the alleys and I have to walk carefully to avoid stepping on them. They transplant fairly easily, even in bloom.

Here in Portland, I have clovers, prunella, veronica, violets, wood sorrel, chickweed, scarlet pimpernel, poppies, scotch moss, (yes) mints and strawberries, field madder, arugula, radishes, beets, cilantro, borage, quinoa/millet... all (near)self-propagating every year.  I keep a shaker of collected seed that I sprinkle on every bare patch of dirt.

You gave me the vapors! I'm also in the PNW, near Seattle, and keep my veggies compost-only - no mulch, no understory - to discourage the slugs. They loooooove understory plants, especially if they have some weak leaves. I already need to clear out the aging bottom leaves of my veggies to avoid putting out a siren call; I'd hate to have to start maintaining an understory! I have a very biodiverse community everywhere else, with lots of groundcovers, but not under the veggies.

I have to say that my groundcovers - blue star creeper, eunmonious, lime, creeping and elfin thyme, alpine strawberries, bugle, sorrel (which overwhelmed the bugle), sweet woodruff, creeping phlox and probably some others I've forgotten do very little if anything to fend off buttercup and bindweed. The weeds I liked - fewerfew, dead nettle and dandelion - disappeared as the soil improved.

Has there ever been a follow through for this experiment ? I dont see one on Jason's blog. I'd like to do something similar at my parents next year.

Mostly wintergreen, wild strawberry, moss, alpine ferns and lichens (which is everywhere here) that I can transplant and some creepers I'll have to seed.