From my perspective as a rosemary stem, the journey begins with a sharp, clean snip. Please ensure your pruning shears are sterilized; I dread the thought of bacteria or fungi hitching a ride and clouding my water, leading to rot before I can even try to root. The ideal cutting should be about 4-6 inches long, taken from a healthy, non-flowering section of the parent plant. The best wood for this is semi-hardwood—not too soft and new, not too old and woody. Make the cut at a 45-degree angle just below a leaf node. This angled cut is not just for aesthetics; it dramatically increases the surface area from which I can absorb water and, later, develop my precious root initials.
Now, you must prepare me for my new aquatic home. Gently strip the leaves from the lower two-thirds of my stem. This is a critical step. If these leaves are submerged, they will decay, releasing organic matter into the water. This decomposition fosters bacterial growth, which depletes oxygen and creates a slimy film that can suffocate me and prevent rooting. The removed leaves also serve a purpose; the nodes where they were attached are prime locations for root emergence. By clearing this area, you are directing all my energy into producing roots from these specific points, rather than sustaining unnecessary foliage.
Place me in a clear glass or jar filled with fresh, room-temperature water. Ensure only the leafless portion of my stem is submerged. A clear glass is beneficial as it allows you to monitor root development and water clarity, but it also lets light in, which can encourage algae growth. This is not ideal, but it is a manageable trade-off. Position my container in a location with bright, but indirect, light. Direct sunlight will heat the water excessively, essentially cooking me and encouraging algal blooms. Please change my water every few days, or whenever it appears the slightest bit cloudy. This replenishes dissolved oxygen and removes any accumulating waste products, keeping my environment pristine for the delicate task of root formation.
This is where my hard work begins internally. Underwater, the cells at the exposed nodes begin to dedifferentiate, forming a callus tissue. This is not a root yet, but a protective layer and a precursor to them. With consistent fresh water and light, hormonal signals, particularly auxins, accumulate at the base of my stem, stimulating the callus to develop root primordia. You will first see tiny, white bumps, which will slowly elongate into delicate, white roots. This process is not quick; it requires immense patience from you. It can take anywhere from three to eight weeks for substantial roots to form. My focus is entirely underground, so to speak, so growth above the water line will be minimal during this period.
Once my new roots are about an inch or two long, I am ready for the most critical transition: moving to soil. My water roots are fragile and adapted to an aquatic life. They are different from soil roots. Do not simply plop me into dense garden soil. You must acclimate me gradually. Prepare a small pot with a very well-draining potting mix, perhaps amended with extra perlite or sand to mimic my preferred gritty conditions. Gently plant me, water the soil thoroughly to settle it around my new roots, and keep the soil consistently moist (but not soggy) for the first few weeks. This helps my aquatic roots adapt to their new terrestrial environment without going into shock.
