Don't till it, it will sprout everywhere. If you don't want any of it, I would wait until it starts to grow again and use round-up on it. If you want a small patch, pull the plants up that you don't want and put a barrier of some sort into the ground to keep it contained...or keep some in a pot. In any case, you will be fighting it for more than one season.

Muwhahahah! We the "Spearmint Are Tough And Nigh-Invulnerable" (S.A.T.A.N.) terrorist organization. We laugh at your attempts to eradicate us! Use your rototiller and see how numerous we become! We will become Legion!

In all seriousness, rototilling it will only increase it. It will resprout from all the root bits...like the hydra resprouting multiple heads for each lopped off. Pull it up roots and all. Repeat. Pull it up roots and all. Repeat....

FataMorgana

FataMorgana, I'm still laughing at your acronym!! That's awesome!

Yeah I won't till it. What about just spreading some mulch on it? Probably not.

I'm nervous about round-uping it. It's right next to my snowball bush and I was planning on planting some stuff nearby as well. Would the stuff and tree be OK if I was to spray it??

Don't spray it - wipe it on. Here in Australia there's a thing called a Weed Wand - sort of a stick with a large 'wick' that looks like it's made of a bit of rope on one end. You fill the stick with the herbicide and wipe the wick over the weeds to moisten them.

You could probably invent your own wand by tying some twisted cloth to the end of a stick, and dipping the cloth into a bucket of herbicide. If you use one of those squeezy buckets it might make life a bit easier for you.

Mulch? Well, it might slow down some weeds, but it won't slow down mint. It'll just encourage it to travel underground to some other place!

As Fatamorgana said (in far more descriptive language) - persistant pulling out is the answer.

How about putting down some plastic, then covering it with mulch? I'm happy with some containers on top for this year. I pulled a lot of stems this morning. Sore fingers I'll tell you. That stuff is wound around this and that and itself to a degree that's just plain scary!

My husband uses a paintbrush with roundup in tight areas.

Put down clear plastic and allow it to remain all summer. It will bake the soil and that should do away with some of the mint. Using herbicides may not help good plants to grow well, so use one thats not selective, but breaks down once it hits the soil. Clove oil and 20% vinegar are quite effective at burning out any plants leaves. Tilling can spread it, but if you till several times in a single season it may help to get rid of it. Till, then put down the clear plastic, allow it to sit a month and bake, take up the plastic, till again, and then set it down again. Do this a third time and should reduce the mint issue for te next year. Years ago, I had mint growing here, that my dad planted, but with my any years of tilling, putting down black plastic mulch in summer for a weed barrier for plants, has virtually eliminated any trace of mint. There is a thing called a 'stirrup weeder' that wil slice through plants at the base, and cut off roots. I use one here, but it is a tedious task. Another option is a propane burner thats on a long wand and uses a propane tank and high pressure regulator to blast and burn any greens at soil level. They are found at Northern Tool

Here is a link that might be useful: Stirrup weeeder

Before you kill it all, and that may take some time and effort, try trading or offering for postage some of those pesky plants. Many new gardeners would love a start of spearmint.

Just be sure to warn them that they will want to grow in containers only.

I know you wouldn't want to try digging it all to trade. However, you could probably make many people happy by digging a few plants.

I containerize my mints as I watched my father fight them for years. However, I have spider plants that have naturalized in my yard. If you watch, you will see me offer them for trade every now and then. By doing this, I am keeping them under control --- just along the fence line. When they start moving outwards, I post an offer.

I haven't tried this with mint, but to destroy a lawn, you can lay down cardboard, then a layer of mulch. By the time all that breaks down, the lawn (or in your case, mint) will be dead, and you'll have a nice rich bed for the next thing you want to plant.

The cardboard/mulch method probably won't work with mint. When it is thwarted by any sort of barrier, it'll just turn around and find an escape route - and reappear some distance away. Nope - if you want to get rid of it, you'll have to kill it at the roots.

Double dig the area, remove all plants, roots, and runners. Place cardboard and mulch over clean area (It doesn't stop it but the new organic matter keeps the soil loose so its easier to remove weeds and new sprouts). Let the area lie fallow for a year, and repetitively weed. At least two more times rake back the mulch and double dig the area again. No tilling, dig with a shovel.

I say learn to love it!! Every morning make some tea and infuse it with crushed mint! Delish!!

gardenboy, I just now saw your zipcode. I grew up in that same zipcode! Email me...wouldn't it be a hoot if we knew each other? Wouldn't be too awfully hard in a village of less than 4000 people, would it?

Turn it into a cash crop. Mint is the signature ingredient in the bouquets I sell at farmers markets. I also sell it in fresh cut bunches (we don't use chemicals in our gardens). No matter how much I have - it is never enough! And when all else fails - muddle it with some rum....or whiskey.....or vodka - until you just don't care anymore.

I kept my Spearmint in a nice large decorative pot in the garden for years. But then suddenly mint began to show up on the outside of the pot. It was then that I discovered a crack in the pot where roots made a getaway and spread to the surrounding area. I have tried every way I know how for 10 years plus to get rid of that dang mint. I have tried the black plastic and mulch and painting it with round up, and pulling it up, digging it up and so far all I have done is spend time and effort. It has now migrated to the lawn and smells wonderful when we mow. If you find a way to get rid of it without the use of a nuclear bomb, please let me know.

Helen