I've always thought that the roots needed air. I've grown philodendrons mostly outdoors in shady areas, and some of the smaller ones will climb trees.

Here's a flower from one of mine in my front yard:

I think you did better by putting yours in soil, so that it can get more nutrients.

Is it an arrowhead (Syngonium) or is it a philodendron? Two different plants with different growing requirements. Syngoniums are often grown as hanging plants......philodendrons rarely so.

Gardengal, it is the Syngonium. Sorry.

Lars, most plants that are rooted in water develop a different kind of root system.....one that is able to access oxygen from the water. This enables the plants to grow reasonably well in water, especially if nutrients can be added and fresh water added occasionally.

Remember, fish need oxygen, too.

Sometimes the plants will suffer when transplanted into a planting medium because their roots are designed to get O2 from the water and not from the potting medium.

Fortunately, a new root system can usually be developed in a short period of time if the long "water roots" are sharply cut back before transplanting.

Jasdip, your syngonium will probably make the transition successfully.

I have both philodendron and syngonium cuttings rooted in water. They seem to be thriving although I don't plan to allow them to became huge plants in their glass vases. Here, a syngonium in an Erlenmeyer flask and a philodendron in a vase 9 inches tall and 3 inches wide.

And the syngonium can be grown in standing water as well, if that is easier

I should have asked before I planted it. I'd rather keep it in water, it would be easier. Or maybe I'll divide it and do both.

You could take cuttings from your now planted syngonium (we call them cat faces as it's easier for us) and put those in water to 'start over' and get more plants. I wait until there is a bit of new growth and a 'joint' where a new face will sprout off--I cut that piece and it roots in water. All of mine are from a long ago in-dirt cat face that I used to have. I kept the rootings in water vases for years, probably like you did and they are happy. I've potted some of them, and they seem happy being in dirt too. I really like this plant as it seems pleased in both mediums and anywhere I put it in the house. It propagates nicely. I like more free plants :) I can't really say that for all my house plants as the house can be quite dark for much of the year. I have a mother in law tongue that is ancient and had one sad sprig. I decided to move it to a sunny room after about ten years and it shot up to many sprigs (needed a larger pot and flowered) and is approaching 5 feet tall. While that's nice, er, um, a bit much in the one sunny room lol. The cat faces are happy in any room of our house, which makes me happy.

eta: yours is very pretty and looks nice in it's new hanging pot. I'm sure it will be happy there. Maybe it would be easy enough to put the pot in the sink for a watering once a week? I get it how hanging plants can be a bear to water without making a mess below.

remember when you grow roots in water ... they will NOT transplant well into soil. Soil roots and water roots are vastly different. Soil roots will absorb ferts better. They take awhile to change from water roots, as the water roots will not have the necessary hairy tendrils to absorb the nutrients ...

I took them out of the soil washed the roots and stuck them back in water. It's easier to change the water and add a bit of liquid fertilizer. They're still hanging, but in water.

I have a plant that was given to me in 1964 by my mother-in-law at the birth of my daughter. It was, of course, potted and for many years I divided it and then finally last year when I got sick of the straggly look I cut it all in the same length strands and filled a large antique crock with water. This plant has never looked better and it's totally growing in water with a massive root system.