Hi Doris,

Columneas don't need any more than 1 - 1 1/2 inches of stem below the soil. I would take off bottom leaves until you have about 1 to 1 1/2 or even 2 inches of stem and don't worry about any roots that are above that. They will just wither away. They won't be of any use anyway. Since they already have roots put the plant and pot in a plastic bag for about a week. The columnea has water roots and will need to convert them to soil roots. The bag will keep the humidity high and give the plant the chance to make the conversion without stressing it.

Good luck and have fun.

Larry