OK, I did it.
I read some articles online about Ludwigia repens and decided to try growing the cuttings I was given. They've been in the tank for a week and look fine.
I have a bottle of "Leaf Zone" that was given to me as well, it contains iron and potassium. Is this enough? I don't really want to buy a CO2 setup for one plant... should I use a different fertilizer or will this be OK for one smallish plant?
As long as you have decent lighting... following the dosage recommendation on the bottle.
In most tanks, a small iron supplement is all that's needed. Especially with a tolerant easy growing plant like L. repens