Living rhizome barrier plants

I really need to keep the quack grass from the mown grass/clover path area out of my annual gardens and forest garden... so i'm thinking of a border for cultivated areas about 3' wide with 2+ species with dense roots to stand guard around the edge. So far i have tried it in one area with just bocking 14 comfrey and it has worked well so far. Next i'm trying Sorrel and turkish rocket with yarrow in front of it. Have other people had success with this method? What other species might work well?

Look into vetiver grass. Very very dense roots.

rhubarb, iris, mint, burdock

Patrick Mann wrote:rhubarb, iris, mint, burdock

I will try out some of those, thanks!

James Colbert wrote:Look into vetiver grass. Very very dense roots.

That's a good idea, but it is not hardy here, i should have mentioned i am in zone 5.

Iris? I would never have guessed. Interesting.

Siberian iris seems like it would work great, german/japanese iris seem like they wouldn't work at all.

muscari bulbs have formed dense borders for me, as have chives.

Periwinkle - Vinca Major is a good barrier plant and fully hardy in uk 2-3 foot clump-forming and spreading. There are also 1 foot max creeping Vinca Minor, but not sure if they are as or medicinal as V . maj:

The leaves, and seeds of the periwinkle contain vincamine, a precursor to the chemical vinpocetine, which is used medicinally to naturally enhance memory in aging minds.1,2 Vincamine is sold as a chemical extract in supplement form, however herbalists prefer the whole herb be used in either extract or tea form. By using the whole herb you receive the balanced blend of healing chemicals found naturally occurring in the plant. Other folk medicine uses include Diabetes, cough medicine, and as a styptic to stop bleeding.

Preparation Methods & Dosage :Teas, tinctures, supplements

Comfrey planted densely is said to stop running grasses cold.

I'll second Ann's recommendation for Chives.

I planted some in a hedge and they are doing amazingly well. They go to seed every year and have filled in gaps nicely. We don't have running grasses to test against, but I can't see anything getting through.

Japanese Mugwort - though the cure may be worse than the disease. At least it smells good.

I too am finding that Irises work, they form a very dense mat. I've also found that oregano and thyme do the job really well, nothing seems to really poke through them. I've just started planting chives, so I am really looking forward to seeing how that works.

Garlic Chive

I use Oxalis. (at least that is what I think it is)
It looks pretty much like a lighter colored clover with pink flowers. Down here in Alabama it grows like wildfire and forms a super dense mat. It doesn't spread fast but when you dig it up and separate the clumps then replant it. It fills back in rather quickly forming a clump about a foot around in a few seasons.

Speaking of oxalis ... Oca does a pretty good job of suppressing other things, as does Mashua (vining nasturtiums). If your winter is not too harsh they will regrow from tubers the following year. And you can eat them as well.

Maximilian Sunflower and Goldenrod.... Very easy to establish and drought hardy.

Both grow very dense (and tall).

,Travis Krause
-parkercreekranch.com

I would argue against chives, oregano and thyme unless you have spent the time to fully dig out and remove all runners of the grass before establishment.  I've worked with all 3 as experiments for beating out grasses and they do a poor job for me where I popped them in and hoped/expected them to beat out the grass.
What has worked with potency in holding back / beating out grass...
Comfrey, Turkish Rocket, Rhubarb, Sorrel, Sweet Cicely, Giant Perennial Sunflower, Jerusalem Artichokes, Elderberry

Hi Aaron, is the roadside daylily, H. fulva, too aggressive a spreader for your spot?  On the mow side it will not be an issue, but on the garden side might make work for you.  The common triploid seems to establish quite thickly for me and the flower shoots grow quickly and make a tender cooked vegetable harvested when the largest flower bud is about a cm long....just feel down the shoot until you feel it's not tough and snap off.  Those you don't harvest will give beautiful flowers.  The variegated version might not be as aggressive.  The hose in hose extra petaled version is a favorite of mine and flowers later than the single.  I'd probably do in clumps with some of the other plants mentioned in between to keep things interesting.  Maybe the variegated horseradish I owe you (I promise that I won't forget) might be ok too, though no experience trying to use it that way.

Best, Greg

If your climate is warm enough for them to stay in the ground and spread, I've used cannas this way against bermudagrass.  The cannas will try to spread themselves into the garden area, but they are easier to get rid of than the grass.  In even warmer climates verging on tropical I would guess that some of the gingers might work as well, and several of these are very useful plants in their own right.

Aaron, I was just reading about allelopathy of brassicas and was wondering if you've noticed successful repulsion of grasses near your Turkish rocket.  I will look more closely at mine this year once the season gets going.  Other members of that family might also be of interest.

Turkish Rocket has been an incredible competitor with established grasses.  I would bet it can even take over and colonize into a lawn.  I may have to test that this spring!

Sean Dembrosky wrote:I would argue against chives, oregano and thyme unless you have spent the time to fully dig out and remove all runners of the grass before establishment.  I've worked with all 3 as experiments for beating out grasses and they do a poor job for me where I popped them in and hoped/expected them to beat out the grass.
What has worked with potency in holding back / beating out grass...
Comfrey, Turkish Rocket, Rhubarb, Sorrel, Sweet Cicely, Giant Perennial Sunflower, Jerusalem Artichokes, Elderberry

What is this giant perennial sunflower you're talkigna bout? Seems pretty interesting. Does it have huge seed heads and yield?

Giant Perennial Sunflower is
Helianthus Giganteus
http://www.illinoiswildflowers.info/wetland/plants/gnt_sunflower.html
Tiny seeds, good for wildlife.  Very powerful grower for us.

Sean Dembrosky wrote:Giant Perennial Sunflower is
Helianthus Giganteus
http://www.illinoiswildflowers.info/wetland/plants/gnt_sunflower.html
Tiny seeds, good for wildlife.  Very powerful grower for us.

What do you mean powerfull grower, that it's good in all type of soil ? Could it be used as human food, or is it too small in your opinion? I'm looking for a sunflower that would be perennial and could yield enough for human consumption.

Definitely not a human food plant that I can tell.  Grows with great vigor so long as there is good sun available.  But if you are looking for a seed to eat this ain't it!