I've not tried petunia cuttings, but geraniums are very easy.

It might be your technique, the conditions you're growing them in (temperature, humidity, etc), or how you prep the cutting (leaving too much stem at the bottom). Can you describe all this to help us troubleshoot.

I don't use Miracle Grow growing media -- I don't want the fertilizer in my mix. That also might be part of the problem -- unrooted cuttings don't need fertilizer, nor can they make any use of it. I've gotten Jiffy Mix seed starting mix at Home Depot before, and it's pretty good -- try that instead of the M.G. stuff.

I use BM 6 or Pro-Mix. I add extra perlite. Quite a bit. I tried many different methods, but this mix seems to work the best.

I also use two totes to make a mini greenhouse. They let in some air. If I need more, I just move the top one slightly to crack it open. Hardly ever deal with mold now. I used to use the six pack seed containers for cuttings, but they dry out too fast for me. I moisten my mix before I fill the containers. That way I have more control. I too, used to have mix way too wet and rotted my cuttings. Not anymore, since changing my setup, system.

The trick for geraniums is to make your cut about 1/4” below a node, because that’s where the roots will form. I stopped losing geranium cuttings once I learned that! Once you get the cut right, they’ll root and grow easily in potting mix or water.

Thanks for posting this and all the tricks. I just bought this geranium and would like to propagate some. Most branches have flowers at the tip. The ones without flowers feel very soft and young. Shall I wait for them to grow harder before taking the cuttings? Thanks!

You preferably want a stem that hasn't flowered, but I have found it works anyway. Just better and faster to root if they haven't. Those are gorgeous!

It looks like in the front left side you have a stem you could do cutting from. I can't see the rest of the plant. I usually take stem with no flowers or just a bud. I pinch the bud off. Never cut off more than a third of the plant. I always strive for less, to be safe. When I'm wanting cuttings, I do fertilize to promote healthy growth and/or water the plant the night before I take the cuttings.

I'd be hard pressed to remove those beautiful flowers!

Have fun and post back with how you did, please!

@gawdinfever Z6, thanks so much for the help and the link. I am eager to try this weekend. Happy gardening 🌼

Forever, your Pelargonium is a Regal type. I've found them harder from cuttings than the Zonals. You might have better luck doing it in the summer than in February. Good luck.

@floral_uk z.8/9 SW UK, thanks for pointing out my geranium is a Regal type. So it blooms in spring. I will enjoy its blooms 🌺 now and wait till later and warmer when its done blooming to start rooting the cuttings