It is the start of powdery mildew. They'd be better off planted in soil and put outside.

Oh, shoot. I discarded them thinking they wouldn't recuperate from a fungal attack.

Well, I'll get some more cuttings and do it again but this time I'll put them in the ground earlier.

Any tips on rooting mint from cuttings? Should I plant them straight in the ground after they root or first in a small container?

As floral said, mint will take over growing by runners underground and can be difficult to control. Best bet is a container. You can size up as the plant grows.

Thanks for the advice. I will grow it in a container.

I would put more of the stem into the water - 3-4 inches of water at least. Some recommend removing all the leaves that are under water and that seems to encourage more roots from the nodes where you have removed the leaves. Roots will strike all along the stem. Once the roots are a couple of inches, plant into a container being careful not to jam them into the soil, make a hole spread out the roots a bit and cover gently. The water roots are pretty delicate although in a short time the new plants can turn pretty invasive. I like to keep them pretty wet for the first week and then water only when dry.

Thank you so very much, ophoenix, for the advice! I will try a third time (the second time the cuttings did not root at all but I will persevere :).

Hang in there! I started some chocolate mint today and transplanted some rooted cuttings. It can be really maddening when you can't seem to get a weed to root! lol

I am almost finished with a DIY for our blog on rooting mint. Send me a private email and I will send you the link when it is done. Meanwhile, impose on family, friends and friendly gardeners to give you pieces of their mints to try. After they laugh, because everyone knows it is simple (not for everyone!) take them home and try with a different type! Put the jars on a bright windowsill. Pretty soon you will have enough rooted to give to friends and all visitors. lol Another place for extras is a food bank. Pot them up in a little soil and they will be loved and cherished by all who take them home.

I'll do that! (I've successfully rooted basil in water a few weeks back. Got 10 happy little basil plants growing in small pots in part sun for now :).

Both the basil and mints root using the same methods! So you have been successful with basil and will be the next time with mint - or the time after. lol I have never found a scientific explanation for why some times they root and other times they don't. Lots and lots of reasons on line - but based on experience only. Some comment that they tossed out the cuttings that would not work and they later found them rooting - not rotting - in the compost pile! Go figure! lol

I had nice mint and peppermint patches growing in full sun back in the northeast. They never became invasive - maybe because they were on a slope that was difficult to water. I have no idea if mint will grow as nicely in full sun here in SoCal. I don't have a part-shade spot for it. This is my first year gardening here and my backyard west exposure makes it very challenging. Even the succulents are having a hard time, half of them have been scorched.

Mint is very easy to root! I bought a supermarket mint plant put them in a container. After awhile I started to clip them off and just stick them in separate pot filled with potting soil & give them plenty of water. They pouted for a few days and then perked right up. I have 4 separate container of mints now and they kept growing.

Tim C, where do you keep the four new mint plants? Shade? Part sun? Full sun?

Bleu, I keep them indoors by the window. They do not get direct sunlight. So you can say they stay in the shade all day.

wife loves it. Every time she wants a tea she’d Just clip off some mint leaves and make “mint tea”!

Tim, where do you live? Mints have rooted quickly in my kitchen sitting in water on the window sill. They are also growing very well on the deck with indirect sun in the early morning and direct sun from 10am till sundown. But it took several failures before this batch - several different varieties all struck. Not sure why, but they are all doing beautifully now. The extra plants will be potted up and taken to the Food Bank where they will be appreciated.

I live in the high desert (antelope valley) of Southern California. I just clip them off and insert into a potting mix, give them plenty of water and in a couple of days they perk right up, go on living as happy as can be. I have a east facing window but I don’t think it matters. I did the same when I lived in Washington DC with a north facing window. They don’t need a lot of sun to thrive. They’re happy indoor plants.