Rocio, first allow roots to reach about an inch..Then when you repot, use a soil that's semi-light in texture. You don't want anything heavy. Water well after repotting, but let soil dry a bit before giving another drink.
I think most coleus die after being rooted is because soil is too heavy and stays soaked. Take a cutting from your red coleus and try again..Toni

I have never rooted them in water....always directly into light moist soil....hmmm.

Web, then that's a differnt story..(S)
Everyone roots plants differenly, but I prefer water then soil.
Are you sure the coleus rooted? If so, how did you find this out? Did u unpot the plant to check? That's another reason I prefer rooting in water, this way you can see the roots.
If you take more than one cutting of your new plant, try one in water, the other in soil..use a light weight soil, Web. Most ppl use rooting hormone before placing plant in soil, too.
Experiemnt with it and see what happens..Sorry for the misunderstanding..Sometimes I jump to conclusions, thinking because I root plants in water everyone does..LOL Sorry about that..Toni

Rocio, your likelihood of success will be increased if you stick your cuttings directly into a solid medium of some sort. Some people use straight perlite, or their own good quality potting medium. The roots that plants develop when grown in water are not efficient once you transplant them into something different, you see. That's the reason for the problems. Truthfully, unless your potting medium is really crummy, most things will root every bit as quickly as in water. But without having to go through the stressful transition process.

Be sure that your cuttings aren't too large, that you make your final cut just below one of the nodes, and that you remove all but the top couple of leaves.

Use a pencil to 'pre-drill' your holes, but water the cuttings in very well to insure soil-to-tissue contact. Place them in a warm, not overly bright location and be patient. Don't keep inspecting the cuttings for roots...you break them off everytime you do so.

If your home is on the dry side, you may want to cover your rooting container with a plastic bag (not too tightly) to create a more humid atmosphere. Keep the soil moist but very cautiously so.

The KEY to successful rooting is probably your medium. Leave out compost, sedge peats, real soil, etc. The coarser your medium is, the better.

Agree with Dorie. Rooting in a solid and well-aerated medium is best and eliminates the transitional shock when moving the plant from water to soil.

Al

Hello, everybody! thanks for your answers. At first I did put root hormone in my cuttings and then put them directly in the soil. It used to work, but for a while everything died, so I started with the water, which for a friend is THE way to do it, and everything she roots in water grows without problem in soil. I do make a hole before putting the newly rooted plantlet in the soil and I water a bit. I also have a humidifier at home, and mist my plants (although the diferences in opinions about this have been long discussed here). I´ll try to take more cuttings and put them in soil directly, to see how they do, although I rather do that in spring, since I have a bad experience trying to grow things in the fall-winter.
Thanks again!!
Rocio