Propagating rosemary is a great starter project if you haven’t rooted anything before—it’s almost fool-proof! Just take some 4-6 inch long cuttings from a rosemary bush that you like (maybe even one from a park or a neglected hedge), peel off the lower leaves so they don’t rot, and stick the sprigs into some filtered water. The best time to take cuttings is early summer, but rosemary can be rooted year round.
In a week’s time, you should have some little roots starting, and if you leave them in for too long, you’ll have a lush tangle of roots within a month or two! Gently separate the sprigs and transplant into a potting mix that has high moisture retention (mixes with coir, peat, or vermiculite are good for this) and keep it pretty moist to start off, gradually letting the soil become drier as the plant adjusts to the life non-aquatic. Soon after, they’ll be ready to transplant outdoors, where they should grow like crazy and give you more rosemary than you’ll ever need in the kitchen!
And you may be seeing more of this blue wall in the photo, as this particular shelf in the kitchen is quickly becoming one of my favorite spots to photograph small arrangements—it seems to give ordinary objects an instant “Dutch still life” treatment—fun!