never tried it..

but the link says it can be done ..

supplemental light is going to be very important.. on a plant the the shear number of flowers these can produce ... and they arent going to like a cold windowsill in z5 in winter .. do you have a light rack???

and if you have a forced air furnace.. spritzing isnt going to provide the humidity you need.. you might want to try a baggie over them ... or something like the pic below ... as a humidity house ...

the other problem.. in z5 .. is how cold the house gets at night.. rooting things in damp cold media.. doesnt work easily.. so a heat mat might be necessary ... in other words.. my thermostat knocks the house temp down to 64 at night.. and that is not rooting temps ...

good luck

ken

this a gallon milk jug.. with a gallon baggie over it.. forget about the rest ...
{{gwi:5067}}

Here is a link that might be useful: link

Petunias are tender perennials, not annuals.

Why not just bring in the original pot, then increase it with cuttings in the spring?

When I've tried cuttings in the spring/early summer, they do well when put directly in soil, no water first. The growth on the plant at this time is probably mostly woody, which would be extremely difficult to propagate even at the right time under optimal conditions. I put a lot of effort into saving this years' "annuals" for next year, but Petunias aren't one I would bother trying, but absolutely wish you luck with your efforts. You certainly can't succeed if you don't try. Have much higher hopes for your Verbena (which I would put in soil as soon as you can.) Let us know how these things go!

Thanks for the input. I will probably do both, i.e. overwinter the main plant in the garage, which stays at 40 degrees, and try to get some cuttings going now.

I do have a heat mat so I put that underneath the pots and I did put gallon ziploc bags over the pots to make a humidity tent but now I seem to have another problem in that it's too damp and I'm getting some mold. I'm guessing the humidity tents are either too small, or just aren't getting enough ventilation in them.

You might not need those plastic bags. I've rooted a lot of things in pots and never used them. Just don't let them dry out.

I don't use a tent either. If you are concerned about humidity place a small container of water beside the pot. You should also mist them.

Where you take your cuttings make a difference and how clean everything too. Here's how you should take cuttings and grow them for any plant

Take your cuttings:

Prepare your pots with moist soiless mix--yes you should use what you use to start seeds. It has better drainage than potting soil and won't keep your cuttings too wet. Dibble a hole where you are planting your cutting so you don't knock off the rooting hormone.

With a sharp knife or razor blade cut a 5 or 6 inch piece from the growing tip, cutting just below a leaf. All roots and branches come from a leaf joint. Remove all but the top 4 or 5 leaves. Dip about 1/2 inch of the cut end in rooting hormone. It comes in powder or gel, either is OK as long as it's for soft wood cuttings. I use Stim-root NO. 1. After it's dipped put it in the hole and cover it in, and you're done.

Keep the soil moist but not overly wet. They will look wilted at first but that will change as it starts to grow roots. You will know it's rooted when it starts to show new growth. Wait until it is rooted well before you plant or move to another container

Potting 'soils' are soilless! Peat-based, soilless potting mediums are pretty much all you can find for containers unless you go looking for bagged garden or top soil. The potting mix I use has more bark than peat and is still considered a soilless medium.

Some potting mixes are very fine-textured (Miracle-Gro comes to mind), almost mucky. Sometimes a heaping dose of petlite can help with porosity. I even like to root cuttings in 100% perlite that has been rinsed and soaked.

I don't typically tent my cuttings, either...unless I'm using the perlite.

My Nana used to root petunias in builder's sand, but I don't remember her ever doing it inside. She was very successful with the sand.

Is it possible to get petunias to root and bloom this late in summer? I bought this plant yesterday and wonder if I can take cuttings and root them in my electric propagator or is that too humid and would make them rot? If I repot it will it increase in size?

Your petunia looks healthy, so it will definitely grow if you give it room. It seems a little small to take cuttings right now. I would repot it, and wait for it to put out more growth before taking cuttings. If you see it is root bound when you pull it out of the pot. Take a razor blade and slice it a few times to break the circular growth pattern and stimulate new root growth.

I have never heard of an electric propagator. Humidity and warmth are good things when starting cuttings. I take dozens of petunia cutting every year and grow them to full sized plants, but it takes a couple of months. I use pearlite, or vermiculite/perlite mixed to root them in. I use clear plastic containers, so I can see when there is root development without pulling them up.

good luck

Thank you for answering. Maybe I used the wrong word. I called it an electric propagator because it runs off the electric. It consists of an underneath tray which is heated with 3 separate trays on it with high transparent plastic covers over them (called mini-greenhouses in Sweden). It sits perfectly on the window ledge in my kitchen. I use it to speed up seed germination and rooting of cuttings. You can also place pots directly (with or without plastic bags or something as covers) on the heated underneath tray which I have done without any cover for a pelargonium cutting as it would not root well with a lot of humidity. When I tried to get pelargoniums to root previously they either rotted in water or mildewed in soil. So far nothing negative has happened to this pelargonium cutting on the heated underneath tray. I am using the mini-greenhouse that is not on the underneath tray to cultivate plants in another window of African Daisy, Naranjilla and Fenugreek prior to planting them on my glazed balcony. If you live in the USA or UK or Sweden and would like to know more about electric propagators email me and I shall email you a picture and give you names of firms that sell them in those countries.

Oh........I have just heard of them referred to as heat mats, with domed trays. They are primarily used here (USA) for germinating seeds.

Bottom heat and humidity should be a plus with the petunia cuttings, I usually cover mine, but I dont have a heat mat.

I had some flats last year that I never potted up and they were small and leggy, so finally in july I put them in bigger pots - and they were the best looking petunias in sept. they even bloomed till thanksgiving a bit.
so this year I decided to rejuve some petunias mid-july. they were from flats that I xplanted twice since may 1 and were getting leggy, even though I pinch them all the time. so 3 weeks ago I took some 6" cuttings, put them in a starter mix and covered with plastic dome indoors: in 2 weeks they were going, one is already flowering! I am planning to do some more.
I think it really helps to start new plants mid-summer to have nice bushy plants in the fall.