Picture a little rosemary tree at your kitchen window, standing there upright and green as if in defiance to the wintry scene beyond the panes.
This little tree offers more than decoration and winter cheer. Pass your hand lightly over the leaves, close your eyes, and the scent will carry you to a sunbaked Mediterranean hillside, the plant’s native habitat. Snip off a few leaves for cooking, and your tongue will similarly transport you to milder climes.
Grown as a little tree rather than as a sprawling shrub (its natural inclination), a rosemary plant takes up little sill space and is easy to prune. Here’s how to make that tree.
START WITH A TRUNK
Begin with a small rosemary plant, grown from seed or cuttings, or bought. Seed is slowest and most difficult, cuttings root easily, and the bought plant will still offer you the satisfaction of training the tree. Even naturally creeping varieties can be coaxed into becoming little trees, but if you have a choice, choose a naturally upright variety such as Majorca Pink or Salem.
Single out one stem to become the future trunk of your plant, completely removing all stems except for this trunk-to-be at the base of the plant. The most vigorous, upright stem is the obvious candidate. In the case of a creeping variety, just select any healthy stem and stake it upright. Poke a dowel or thin piece of bamboo into the soil near the base of the plant and tie a piece of soft yarn tightly around the stake, then loosely around the stem.
As growth begins, the trunk-to-be will elongate, new stems will sprout out along it, and other stems might sprout near the base of the plant as trunk wannabes. The latter are most common with creeping varieties, which have bushier inclinations.
Your goal in the weeks ahead is to promote elongation and thickening of the trunk-to-be. To that end, keep cutting away any new stems sprouting from the base of the plant. Pinch back to just a few leaves any stems sprouting along the trunk-to-be. Doing so keeps them subordinate but lets them help thicken the trunk.
AND NOW THE HEAD
Once the trunk reaches full height, your goals change: You now want to stop growth and create a bushy head. But how high is “full height”? It’s all for show, and what looks good depends on how big a head you are going to give the plant and how big a pot the plant will eventually call home. Generally, a head 2 to 3 times the height and just slightly more than the width of the pot looks good. Stop growth at the desired height by pinching off the growing tip of the trunk, a simple operation that awakens growth of buds down along the trunk.
Create the bushy head by repeatedly pinching — and thus inducing more branching — the tips of all shoots that sprout from the top few inches of trunk. Now define that head more clearly by completely removing all stems and leaves further down the trunk.
All these prunings need not be wasted, of course. They could be used as flavoring or as cuttings to make yet more plants.
Maintain your little tree by repeatedly nipping back the ends of stems, which keeps your plant compact, neat and elegant.
A final tip: Although rosemary thrives in the dry air of the Mediterranean region and of our homes, the soil must be kept moist. Rosemary’s narrow leaves never droop, so your only indication that the plant needs water might otherwise be a dead plant.