My old aunt told me about that method but didn't elaborate on just how to take the cutting and how to prepare it. She said to wrap the bottom of the stem in a ball of clay, presume she meant clay soil, then plant and cover with mason jar as you said.

Problem is a lot of people think there are better methods now.

Be that as it may, how do you keep the rose cutting's leaves from touching the side of the jar? Does it matter?

no never matters if the leaves touch, the stem dies back but it comes back in the spring.i never have a problem set it and forget it, unless its in a place where you don't usually water.never covered in clay soil,i would think that would be to hard to root in for the plant, but what do i know.i did try it as another person wrote here ,with a plastic bottled it didn't take for any of the plants.however i do live in upstate ny wet,cold,windy winters.
as for better methods,flowers have lived many a year with no babying.of course if thats all they got to do go for it; "grannys bottle method" is free,mostly effertless and works.good luck GOD BLESS

Is it too late to try your method now and just leave it be until next spring?

I have plenty of quart mason jars, but if it doesn't matter if the leaves touch, could I use an ice tea jar, also save pickle jars? That has a little more clearance on the top, maybe not such a good idea if the rose shoots off new leaves sideways.

I don't know why the clay, it would be similar to soilless medium except much harder for the roots to push around in and out of, but you know our grandmothers used methods they learned locally from their friends and I'm sure they didn't use rooting hormone so maybe the dampened clay kept a compact mass against the rooting area, I don't know but don't have much clay and don't want to go that route.

If I try your method, I am going to use a variation. I've had two leaves just start showing on cuttings I started back in late May I think it was. I thought they all were dead and was about to throw them away. I cut a hole in the bottom of a clear 16-oz plastic cup and filled it with good quality potting soil, used some rooting hormone, and buried my cup in the ground but decided not to cover it (they need the humidity) because I wasn't sure about the leaves touching the pepsi bottle. I figured it would be less root disturbance when I move it to its permanent location or pot it up in a larger pot, and people here say plant in the shade not the sun for several of their methods. I put mine on the east side of the house and propped an old window screen against the house so the sun would be filtered even though it gets less than half a day of sun. Even so, all the leaves gradually died on all my 12+ cuttings I tried.

I tried the ziplock bag method in my sunroom in a west window a couple years ago, they looked ok for a week or two, then all of a sudden rotted so I won't be doing that again and I didn't want to mess with hardening them off outside anyway.

One more important question. Do you just remove the jar one day and leave it off in the spring or do you leave it off a little more each day?

I'm always looking for the easiest way, willing to do some of the techniques I've read here, but they involve a lot more fussing. I don't mind a process that takes longer if it is likely to work in the end.

Thank you so much for sharing your method. I read and read here and on the net. One lady did use a mason jar but she swished some potting soil around in the moist jar to create a film to filter some of the sun out. You say you can put them right in the sun. I'd be afraid that would be too hot for them. What is your approximate success rate?

when i did the first two, i went to my 93 year old rose lady and said..thier dead! she told me and i must agree it sounds right, the plant puts most of its effort into the roots how can a baby grow leaves and roots at the same time.and how can the baby feed when you don't have enought roots to support it.you want roots first,leaves will come later.well it seems to be true.i have done this over 30 times at my camp,work and the old house and now the new one.i lost maybe 5 total.the reason i lost them seem to be my fault,as my rose lady(who has gone on now) said do as i say well i didn't always.they die for me when i use plastic bottles and they die when the bottle is to big.plastic seems to not be enought protection in my area and for the to big jars i think its to much condensation and to much room to fill with cold air.the soil seems to keep the small jar warmer.i tried a big jar once hoping to remove it to a big plant..i got ice instead.condensation froze the baby.
as for the sun none of them were really all sun,i would say morning sun early afternoon.hot sun will get too much condensation and that will not work.i never did total shade,they need some sun to feed.as for the dirty jar method??? you have condensation right from the start,it would just wash down the sides.i do plant the jar with soil around the lip to hold it in place and keep the heat in.
as for taking off my jars, i wait till its safe for annuals here about the end of may.then i just open them right up to the cruel world. they are babys but they usually give me a few buds by the end of the first summer.slow maybe,but worth it.