Curious. I've never seen that on Pelargoniums. One way to find out .... I'd try it just like stem cuttings. I see no reason why they wouldn't root.

Are you sure that is a proliferation or just another flower stalk. I have grown geraniums for years both from cuttings and seed. Occasionally I have had Geraniums that send up another flower stalk from the first one but never a new plant. When they do this there are a few small leaves and buds.

Even if it were a proliferation which I doubt you can't plant a flower stalk. You can however take cuttings from the growing tips of your plant and plant them.

Any chance of a picture to pin down exactly what is going on? I was imagining plantlets, which as I said I've never seen on Pelargoniums. If it's still just flower stalks, then no, they won't root.

The proliferations hardly have any stems of their own where they sprout from the flower stem, so not sure how to root them. Here are some pictures:

Regardless of what you think it is there is one sure thing. Cuttings or any part of a plant you wish to root must have leaf nodes( places where a leaf grew). All new branches on a plant come from a leaf node and all roots come from a leaf node. If there's no leaf node you won't get roots

I broke off one of the flower stems that had little leaf sprouts on it and put it in a glass of water in my window before I went on a 12 day vacation. This is what I found when I came back (see photo).

Interesting and we'll all be curious to see if the top continues to develop when the thing is planted up.

I've thought it over and looked over your pictures and I think I know what you have. I'd be interested in seeing where these sprouts are joined to the plant but I'll venture a guess that they are joined to a branch or the stem and I think I'm right.

I think your Geranium sent out new branches but because your plant is so bushy those branches did not send out leaves because they were searching for light. Instead they sent out a long stem and the leaves developed when they hit the light. It is a fact that all branches and roots come from a leaf node and that is borne out by the fact that you do have a leaf node at the bottom of the branch in water.

It may looked like it came from a flower stalk but flower stalks grow next to leaf nodes

I checked out your theory. Here is a flower stalk that has undeveloped brown flower buds next to the leaves on its top:

Here is another stalk with leaves instead of flowers:

This plant has not bloomed for several months, but keeps producing these other stalks. I read in another place that these type of stalks sap the plant's strength and are unproductive, so they should just be removed. I removed the rest of the proliferations because I want the plant to flower!

They are not proliferations but branches. They come from a leaf node on the branch although I've never seen 2 coming out in one place. I don't know about them sapping the plants energy but it does not hurt to remove them and may help. I bring some Geraniums inside every fall and let them grow under lights until spring. Then take cuttings. I plant all cuttings and mother plants outside after removing them from the pots they grew in and planting them in the ground or other pots.

Your plant is pretty bushy and it looks like it overfills the pot and is not as dark green as those small ones nearby. If that's the same pot it grew in last summer the soil may be depleted and it may be pot bound. Maybe that's the reason your plant stopped blooming. I'd move it to a larger pot with fresh soil or do it when you move it outside

Thanks for your input. I'm not an expert on geraniums, but this plant appears to be unique in its growth pattern. After the weather warms up, I will be planting it and any rooted cuttings outside in my garden bed where they will probably do better.