The plant commonly referred to as Citronella, especially for propagation via cuttings, is typically the scented geranium, Pelargonium citrosum, and not the Citronella grass, Cymbopogon nardus. This lemon-scented geranium is a popular choice for gardeners due to its aromatic foliage. Propagating it in water is a straightforward method. This technique relies on the plant’s ability to form adventitious roots when a stem segment is placed in a moist environment. The following steps detail the process for successfully rooting and establishing new citronella geranium plants.
Selecting and Preparing the Cutting
Choosing the right material ensures successful propagation. Look for a non-flowering, semi-hardwood stem from the parent plant; this means it is mature but still slightly flexible. Avoid very soft new growth or overly woody sections. The ideal cutting size is approximately four to six inches long, which provides enough energy reserves for root development.
Use a clean, sharp blade or shears to make the cut, preventing crushing and the introduction of pathogens. Sever the stem just below a leaf node, the point where a leaf meets the stem, as this area contains hormones necessary for root initiation. Remove all leaves from the lower two-thirds of the cutting; foliage submerged in water will rot, contaminating the water and causing the cutting to fail. Leaving only two to four healthy leaves at the top allows for minimal photosynthesis while reducing moisture loss.
Executing the Water Rooting Process
Once prepared, place the cutting in an environment optimized for root formation. Select a small jar or vase that holds the cutting upright, allowing the bare stem base and leaf nodes to be fully submerged. While a clear container allows for easy observation, an opaque container can deter algae growth, which competes for oxygen and light.
Fill the container with clean water, such as tap water that has sat out for 24 hours to allow chlorine to dissipate. Place the jar in a location that receives bright, indirect light. Direct sunlight can cause the water to heat up, potentially damaging the forming roots. Maintaining a consistent environment supports the rooting process.
Change the water every three to five days. Stagnant water quickly becomes depleted of dissolved oxygen, which is necessary for healthy root development, and harbors bacteria that can cause the stem to decay. Fresh water replenishes oxygen and removes harmful compounds leached from the cutting. Within two to four weeks, small white adventitious roots should emerge from the submerged nodes, signaling the cutting is ready for the next stage.
Transplanting the Rooted Cutting to Soil
The transition from water to soil is delicate, as the new water roots must adapt to a drier, nutrient-rich medium. The cutting is ready when the new roots are approximately one to two inches long; waiting too long results in roots specialized for water, making the transition more difficult. Prepare a small, four-inch pot using a well-draining potting mix. A mixture amended with sand or perlite is ideal, preventing waterlogging and root rot.
To avoid damaging the fragile water roots, use a finger or pencil to create a small hole in the center of the potting mix. Gently lower the cutting into the hole, ensuring all roots are within the soil, and lightly tamp the medium around the stem to secure it upright. Immediately after planting, water the soil thoroughly until it drains from the bottom, settling the soil around the roots. For the first week, keep the potted cutting consistently moist and place it in a shaded area to allow the water roots to acclimate. This “hardening off” period minimizes transplant shock and helps the plant establish before moving to a permanent location.