Cannabis cloning is a propagation technique where a small cutting is taken from a mature “mother” plant, allowing it to develop its own root system. This method ensures the new plant is genetically identical to its parent, preserving desirable traits. The cutting must transition from relying on the mother plant to becoming a self-sufficient organism. Under properly managed conditions, cannabis clones typically root within 7 to 14 days.
Expected Duration and Stages of Rooting
The complete rooting process generally takes between one and three weeks, with most healthy clones showing roots by the end of the second week. Variability in this timeline depends heavily on the specific strain’s genetics, the health of the mother plant, and how closely the grower maintains ideal environmental conditions.
The first three days represent the initial shock phase, where the cutting focuses on stabilizing itself without a functioning root system. During this time, the clone must absorb moisture directly through the leaves to prevent wilting and dehydration.
Following the initial shock (days 4–10), the cutting forms a callus, an undifferentiated mass of cells over the cut end. This callus tissue is the precursor to root emergence. If conditions are optimal, tiny white root initials may begin to poke through the callus layer.
The final stage (days 11–21) is where the majority of visible root growth occurs. A clone is considered fully rooted once white root tips are clearly visible. Successful rooting is often confirmed by observing new, upright vertical growth at the tip of the clone, which signals that the cutting is actively taking up water and nutrients. Once a dense mat of roots emerges from the bottom of the rooting medium, the clone is ready for transplanting.
Optimizing Temperature, Humidity, and Light
Creating a warm, moist microclimate encourages cell division and prevents water loss. High humidity is a primary requirement because a fresh cutting cannot draw water from the substrate without roots. A relative humidity level between 70% and 90% is commonly recommended, often achieved with a humidity dome, to minimize transpiration and keep the cutting turgid.
Maintaining a slightly elevated air temperature, ideally between 72°F and 77°F (22–25°C), promotes the metabolic processes necessary for root growth. Furthermore, ensuring the rooting medium itself is at the warmer end of this range can accelerate cell division in the stem tissues. Using a heating mat beneath the cloning tray is an effective way to gently elevate the medium temperature.
Light intensity must be kept low during the rooting phase. Gentle lighting, such as low-intensity LEDs or fluorescent fixtures, provides just enough energy to support the plant’s minimal needs without causing heat stress or drying out the leaves. Some growers prefer a light spectrum with a slight preference for blue, which encourages compact, healthy vegetative growth.
Technique and Substrates for Successful Cloning
Cuttings should be taken from the mother plant using a sterile blade. Make a clean, angled cut just below a node, which is a growth point where hormones naturally accumulate. Removing the lower leaves and lightly scraping the stem near the base exposes more tissue for root formation.
Immediately after the cut, the stem should be dipped into a rooting hormone. This hormone, which can be a gel, powder, or liquid containing auxins, stimulates root growth. The hormone seals the vascular tissue and provides a concentrated dose of compounds required to initiate new root development. Gels and powders are often preferred because they adhere well to the stem.
Substrate Selection
The choice of rooting substrate plays a role in the timeline, as various media offer different balances of moisture retention and aeration. Common options include:
- Rockwool cubes
- Peat or coco coir plugs
- Specialized cloning collars for hydroponic systems
Rockwool is favored by many commercial growers for its inert nature and consistent structure, while coco coir offers a highly aerated environment.
Cutting Location
Cuttings taken from the lower parts of the mother plant often root faster than those from the top. This is due to a naturally higher concentration of rooting hormones found in the lower branches.