Setting up large garden: mint invasion

This coming year I'll be working with one other individual to grow a large garden   The soil is well drained, sandy loam soil. I shall appreciate feedback on what to do with a couple of deep root mint species.  They have spread to many parts of the garden. It has been difficult to keep them from spreading fast during the growing season last year.  I was thinking to cover them with a good 6-inch layer of mulch, but wonder if they will eventually work there way through the mulch.  Has anyone dealt with mint invasion?

If this were my problem I would cover the affected areas with cardboard then 6" to 2' of wood chips.  

If wood chips are not available then whatever kind of mulch which is available.

They are likely to spread. One thing to do is to physically separate an area where they can grow, and rip them out everywhere else. I think Anne is on the money with cardboard smothering. If they do start getting out of control, start pulling them out!! I have the same issue in my garden with 3 kinds of mint, I let them grow for my uses in the "trails" between my beds, and rip them out mercilessly for rabbit fodder when it's wet, and to dry for tea on the rare days when it's not raining.

Thank you Tereza and Anne.  I really appreciate it.

I've heard cardboard used to help control weeds, but was never settled with the C:N ratio of cardboard.

Isn't cardboard very high in carbon? In this case much higher C:N than decomposed wood chips (decomposed for a year with chicken manure).  If so, wouldn't microbes rob nitrogen from the soil to break the cardboard down?  Maybe I can soak the cardboard a bit in some diluted fish emulsion or put a layer of rich compost before laying the cardboard?  Do you notice any stunt in plant growth or greenery when cardboard is used?

Sorry for asking so many questions.  I've never used cardboard and just want to be sure.  But I really like the idea of cardboard for blocking stubborn weeds like mint which at this moment is pretty well all over the big garden.  We also have several types of crab grasses.

I have a very aggressive mentos mint that I accidentally set loose on my first year gardening here in Colorado.  Now it is everywhere! Almost everything you do will be temporary -- good for a season or two. Here, it even has grown under the concrete patio and come out the other side.

My best tips for removal are:

1) If the mint is in your vegetable garden space, keep making deep soil.  I used a double dig method to jump-start the clay soils here, then started deep mulching every year, and 2 years ago started "no-dig" wood chip mulching.  The soil has consistently improved every year to where it is almost loose and rich.  Which just makes the mint want to grow there more!  But the loose, rich soil makes it very easy to pull out the mint.

2) Pull out everything you don't want.  You will undoubtedly miss some and it will still come back anyway.

3) Get it in spring while it is small.  And then again later in fall when it sends out runners.

4) Feed it to your chickens after removal.  In fact, if you plant it in your chicken run, it's the one place where it doesn't stand a chance.  Chickens trump mint.  You can try letting them "tractor" over the area, but if they aren't in the space continually, the mint will grow back.

5) Learn to love it.  Start making lots of mint recipes.  Mint ice cream is particularly good.  Mint tea is always a favorite and it makes lovely gifts.

Good luck.

Jean Rudd wrote:I have a very aggressive mentos mint that I accidentally set loose on my first year gardening here in Colorado.  Now it is everywhere! Almost everything you do will be temporary -- good for a season or two. Here, it even has grown under the concrete patio and come out the other side.

My best tips for removal are:

1) If the mint is in your vegetable garden space, keep making deep soil.  I used a double dig method to jump-start the clay soils here, then started deep mulching every year, and 2 years ago started "no-dig" wood chip mulching.  The soil has consistently improved every year to where it is almost loose and rich.  Which just makes the mint want to grow there more!  But the loose, rich soil makes it very easy to pull out the mint.

2) Pull out everything you don't want.  You will undoubtedly miss some and it will still come back anyway.

3) Get it in spring while it is small.  And then again later in fall when it sends out runners.

4) Feed it to your chickens after removal.  In fact, if you plant it in your chicken run, it's the one place where it doesn't stand a chance.  Chickens trump mint.  You can try letting them "tractor" over the area, but if they aren't in the space continually, the mint will grow back.

5) Learn to love it.  Start making lots of mint recipes.  Mint ice cream is particularly good.  Mint tea is always a favorite and it makes lovely gifts.

Good luck.

Hi Jean,  thank you for those helpful tips.  I'll direct the chickens to spend blocks of time in designated areas of the garden.  You gave me an idea also to see if I can come up with new recipes using mint.

Crab grass, by the way, is on my list for yanking also.  Do NOT let it set seed.  Here it seems to have 2 easy seasons to yank when it's small -- in the spring when you first see it spreading its little crab-like grass leaves and then again in fall. Get it as soon as you see it!  I've never tried smothering it -- it seems more aggressive than mint even!

I have some bully mint too, but what I do is just treat it as a wonderful free volunteer and I cut it to the ground whenever I see it and use it.  There are so many uses for mints that it's easy to make use of. Here are 30 great ways to use mint. It eventually gives up and just grows elsewhere for me.

PS  If you have chocolate mint I found that I could transplant mine to a shade area and it became the most fabulous groundcover.  It stays rather low and pretty, with dark leaves, and when you walk on it the entire yard smells heavenly.  It spreads well even in shade but not in the aggressive way that other mints do.  I have shared it with so many friends for problem shady areas of their yard.

Lem Huang wrote:If so, wouldn't microbes rob nitrogen from the soil to break the cardboard down?

My impression is that this happens only at the very thin membrane between the layers and doesn't really have much effect on nitrogen availability in the strata below.

Alicia Bayer wrote:I have some bully mint too, but what I do is just treat it as a wonderful free volunteer and I cut it to the ground whenever I see it and use it.  There are so many uses for mints that it's easy to make use of. Here are 30 great ways to use mint. It eventually gives up and just grows elsewhere for me.

PS  If you have chocolate mint I found that I could transplant mine to a shade area and it became the most fabulous groundcover.  It stays rather low and pretty, with dark leaves, and when you walk on it the entire yard smells heavenly.  It spreads well even in shade but not in the aggressive way that other mints do.  I have shared it with so many friends for problem shady areas of their yard.

Thank you for that excellent article on mint use. I've decided to use all the mint in the garden in a positive way.  I also looked through the website and like it very much.

Christopher Weeks wrote:

Lem Huang wrote:If so, wouldn't microbes rob nitrogen from the soil to break the cardboard down?

My impression is that this happens only at the very thin membrane between the layers and doesn't really have much effect on nitrogen availability in the strata below.

Thank you Christopher.  I'll try a few sections in the garden this spring.

I've got quite some mint growing in thé garden. I accept it in one place only and have it surrounded by slaps of half round wood with bark.. Cut off pièces of a mobile sawing opération in thé village.
That's not enough. Thé mint tries to make it's way out. But i keep it in check like a jedi ninja. And i have planted thé big comfrey all around it. Which keeps it more or less in check in summer.
Mint takes some work.

In the house garden it grows in a raised bed of dry walled rocks filled with compost. It's surounded by grass which grows in uncomposted dirt. If it manages to compète with the grass usually it just gets mowed.

My experiences with mint and containing mint.

Years ago in the US my mother had planted mint that had spread aggressively all around some beloved rose. I spent a day or two crawling around under there digging out as much as I could. I didn't keep any growing at all because I assumed it's impossible to eradicate and it would come back somewhere. It didn't. And then I missed it, haha!

Here in my current garden in the high desert, where I've been at this house and garden for 5 years, I've kept one patch under control. It's in a little corner in my greenhouse, just 2x1 foot, between two walls, an oregano plant, and a mulched asparagus patch. It stretches out into the mulch of the asparagus patch but because it's mulched so the soil is soft, I'm able to pull it back out and pull it off back at its own area. In summer the asparagus is dense and fully shaded enough that it doesn't spread into there. When it spreads into the oregano, the good thing is the oregano is so dense the mint can't get into it, but the drawback is they look so similar I might miss it and let it get established somewhere alongside the oregano.

I planted it on the greywater canal, and cut it down from time to time to mulch the vegetable garden. This is a good usage so far for 5 years, but it certainly is spreading along the greywater canal. Well, mulch and biomass are in short supply here so I don't really mind.

Two mint recipes from India (before I go look at that page of recipes somebody posted)

1) Mint lemonade as an actual dark deep green drink. Put mint with lemon juice, water and sweeter in the blender. You can drink it thick like a smoothie, but sometimes if the mint was tall it'll be too fibrous. Or you can strain it through a tea strainer or sieve and it's a regular juice, but deep dark green. Very nice.

2) Chutney. Several friends of mine from different parts of India have made various chutneys that involve fresh green herbs, garlic and green chillies or red powdered chillies, and either nuts or yogurt for the body, ground up to a fine paste in the blender. Delicious stuff!

2a) My favorite, made by a Gujarati friend, is cilantro, mint, peanuts, garlic, green chillies and salt, ground to fine paste in the blender. Can be spread on toast, a sandwich filling, or a spicy chutney alongside a meal, and you'd adjust the salt and spice level accordingly.

2b) Kashmiri mint walnut chutney
https://recipes.timesofindia.com/recipes/walnut-and-mint-chutney/rs58430697.cms
1 cup walnuts
1/2 cup mint leaves
water as required
2 cloves garlic
1 to 3 green chillies
salt as required
Soak the walnuts for one hour.
Then grind up the nuts, mint, garlic, and 1 of the chillies to a fine paste or puree, adding water as required.
Add salt and more chillies to taste.

Rebecca Norman wrote:My experiences with mint and containing mint.

....

2b) Kashmiri mint walnut chutney
https://recipes.timesofindia.com/recipes/walnut-and-mint-chutney/rs58430697.cms
1 cup walnuts
1/2 cup mint leaves
water as required
2 cloves garlic
1 to 3 green chillies
salt as required
Soak the walnuts for one hour.
Then grind up the nuts, mint, garlic, and 1 of the chillies to a fine paste or puree, adding water as required.
Add salt and more chillies to taste.

Thank you Rebecca!  I will definitely give this recipe a go.

Since the first mint I planted died, I thought it wasn't really invasive, and was proved very wrong . Luckily mine was in a raised bed. I ended up having to totally redo it.
I think the first one didn't live because I didn't water enough.  I wonder if you covered the area with black plastic, and didn't water if that would kill it out?
I still plant mint in the garden, it's a great companion plant. I plant it in a nursery pot making sure the top is a couple of inches above soil level.  This works pretty well.  I noticed  the other day I haven't been trimming it enough and it's rooted in the bed. I will get out this weekend and make sure I get it before it established itself, or I will be in trouble once again.
Good luck

Jen Fulkerson wrote:.... I wonder if you covered the area with black plastic, and didn't water if that would kill it out?...
Good luck

Thank you for replying Jen.  Yes, that would work also, but we wanted to reduce the use of plastics.  We will be trying out some cardboard at a designated area in the garden.