How to Pot Up Rosemary
To be honest, I’ve killed more than my fair share of rosemary. In Maryland, rosemary was happy outside all winter. With plenty of sun and good drainage a small plant could quickly became a substantial shrub. The past few years here in Massachusetts have been much colder. My first winter, I left the rosemary planted in the front garden—it died. Last winter I moved a lovingly potted rosemary to a sheltered spot—it died too. This year I planted the rosemary in my most sheltered but well draining spot in the front garden. We'll see if it survives. As a back up, I just purchased a second little bush to grow in my basement under lights.
Most potted herbs you buy from a nursery will be a bit root-bound like this one and benefit from a slightly larger pot. You can see the roots have circled around and around as the plant got a bit to big. The soil on this one is still moist and the roots are flexible. Avoid plants with shrunken dried soil and crispy roots.
Loosening up a root-bound plant before potting up can help stimulate growth by encouraging the roots to take advantage of the new soil. Often I score the roots with a few shallow cuts to get things started. Then I gently massage the root wad a bit with my fingers. The end result is no longer pot-shaped with nicely tousled roots.
I chose to plant my basement rosemary in a leftover plastic nursery pot. The plastic will hold on to a bit more moisture in my dry basement, giving me a few more days in between waterings. A terra cotta pot would be definitely be more attractive, but this is a basement project. I used a mix of potting soil and cactus soil to hopefully improve drainage. (and I had a big bag of cactus soil leftover from my recent sempervivum project) Freshly potted plants should be watered well and kept out of intense sun for a day or two to recover.
The only thing left is the haircut!
Ok, the haircut is optional. I want my plants to fit nicely under the grow lights, so it helps to use pots of similar heights and trim the foliage. I also have enough rosemary currently growing in the garden that I don’t need to worry about a shortage before the potted plant fills out.