You could root rosemary in water, but there is no reason to. Why make a plant go through that stressful process twice? Water borne roots are different than those developed in a solid medium.

Take three or so inch tip cuttings, remove bottom leaves carefully. Insert the cuttings into a coarse potting medium (part potting mix and part perlite), water them in thoroughly, and place them in a warm, fairly bright location until rooted....about 2 to 3 weeks (or more at this time of year), and ready to repot in several weeks.

If doing several cuttings, don't over crowd them. Be careful not to over water your cuttings, and do not pull them from the soil to see if they're 'ready'. New root hairs break off every time you do that.

If taking cuttings from outdoor grown plants, be CERTAIN that you are not bringing spider mites in with you.

I know that roots grown in water have an outer, spongy layer which makes them unsutable for growing in soil. The growing tips of the root, and young roots, do not have the altered morphology. All I want to do is start it in water, and when roots are just beginning to grow, I will then transplant to soil for it to actualy root. In this way I can avoid having to pull it up to see if it's starting to root. I also read that they should be semi-hardwood cuttings, not tip cuttings.

Cuttings taken from established plants is the best means of propagation. Take 4-6" tip cuttings from a ripe, flower-free shoot in late spring to early summer. Remove the lower leaves, then place the cuttings in a sand/loam/leaf mold mixture or a rooting compound such as vermiculite until the roots have formed. Once the root system is established, plant cuttings in pots or outside in a sunny location. These cuttings should be taken from plants that are at least 2-3 years old.

I know this is a very old thread but I hope someone will respond. :) I'm in NC Zone 7b. My rosemary winters over and I have "shrub" sizes in the yard. I have a feeling this isn't the optimal time to do this, but if I take the cuttings now, could I root them under lights inside and sink the pots outside when we start to have warmer days? Thank you in advance.

I just have to ask why? If you wait until the summer you can just pull off twigs and stick them in the soil outdoors. They'll grow. But if you want a winter project go ahead. I expect it will work. But you will need to guard against overwatering and too much moisture around the tops and causing mould.

You can start them now, better with bottom heat. You will need to tent or mist until rooted. Normal amount of light needed for starting cuttings. I usually start four in a four inch pot, tented and on a 70 degree mat. I remove the tent every couple of days to vent the excess moisture and prevent mold growth. I turn the plastic tent inside out when replacing it, thus the condensation moisture on the inside of the plastic is removed. Al

I took 3" rosemary cuttings beginning of April last year, inserted them in a 1/2 perlite, 1/2 potting medium and placed them in a doomed tray over bottom heat. They rooted in 4 weeks and were potted on into 4" pots and were ready for my mid May plant sale. I wouldn't try doing them earlier here, since I find that light conditions aren't bright enough in my latitude until April (PNW).

madrone
I think you mean a domed tray over bottom heat.
I have always found with Rosemary cuttings, April /May to be the best time for rooting.

Here is a link that might be useful: Gardening tips and ideas

I have a large rosemary tree that is at least 10 years old. A large branch got broken off from the trunk. It is at least 3 feet long and has many branches on it. The stem is around a 1/2 inch round and brown wood. Can I stick it in soil and hopefully grow another plant from it or root it in water? I am upset it was broken off and would like to know if I can save it.

It is unlikely to grow from a thick branch. But you could make a lot of smaller cuttings from the materiel. Root in a coarse medium or the ground rather than water.