The Future of Cloning Explained

One of the biggest questions confronting cannabis cultivators is whether to grow from seeds or clones. Both options unlock a range of choices and challenges. Companies seeking new phenotypes often opt to grow from seed, because seed-grown plants provide crop diversity. But many commercial cultivators want predictable results, so they choose to grow from clones.

Clones are cuttings taken from a mature plant, so they should express the same genetic traits — like cannabinoid profile and potency — for which the parent plant was selected. Slight variations in the plant’s phenotypic, or visual, expression may emerge if the environment shifts, but genetic makeup remains the same.

Clones often come from plants called “mothers,” which are prevented from flowering specifically so they may be used to produce clones. Mother plants typically are sequestered and tended with extreme care to ensure they continue to offer viable cuts. The typical lifespan of a mother plant is six months to a year, although some breeders maintain their mothers for longer.

Tissue culture (TC), a specific type of cloning that often allows mother plants to produce more offspring than are possible with traditional cutting methods, is becoming prevalent among commercial cannabis cultivators. In TC, which has been used for decades in traditional agriculture, tiny pieces of plant tissue are suspended in a special growth medium. As the tissue develops, it can be divided and propagated, providing consistent crops and preserving heirloom genetics.

“By working at a cellular level, TC ensures genetic consistency, making it a preferred method for mass-producing elite plant varieties that maintain desired traits such as higher yields, improved resistance to pests and diseases, and uniform growth patterns,” said Yoni Kalin, chief executive officer at Plant Cell Technology, a global supplier of TC equipment and solutions.

Tissue culture 101

TC may be deployed in multiple ways in a cannabis facility, but nodal and meristem are the most common culture types. In nodal culture, where many cannabis growers start their TC journey, tissue is extracted from a plant, sterilized, and then placed in an agar solution along with a blend of nutrients, sugar, and hormones.

In meristem culturing, on the other hand, plant material is harvested from a region of undifferentiated cells toward the top of the plant’s growing points where vascular connections to the rest of the plant has not yet been established. The tissue may be taken from a nodal culture or a mature plant.

Both versions of TC offer similar benefits, particularly the ability to store genetics while eliminating exposure to pathogens and pests. Meristem culturing takes things one step further than nodal culture. Since the cells used in meristem methods are independent, they’re more likely to be free from diseases like hop latent viroid (HLVd).

Once the plant cells are suspended, they can be multiplied and transferred to a rooting medium. After the new clone has developed roots, it can be transferred from the lab environment to the grow or stored indefinitely as long as the agar and plant nutrients are refreshed regularly.

Benefits of tissue culture

The ability to protect plants from infection or infestation is one of the main reasons cultivators turn to tissue culture. One sick plant can spell disaster for an entire crop,leading to lost time, profit, and reputation. TC gives cannabis plants a healthy start and helps breeders weed out illness. 

Growers also appreciate the space and time TC frees up in a facility. Mother plants take up a fair bit of real estate and must be watered, fed, pruned, and kept well-lit. Cultured tissue, on the other hand, requires a far more reasonable footprint and less upkeep, making TC particularly attractive for cultivators in smaller facilities with a lean staff.

Preservation is another benefit of TC, particularly for breeders, as culturing tissue ensures valuable cultivars maintain viability. That’s not guaranteed when growing from cuttings, as cultivators increasingly cite the tendency of clonal lines to deteriorate over time, eventually resulting in “clones with less vigor and lower cannabinoid levels than the original mother plant.”

Kalin also pointed out another advantage of TC: the ability to propagate plants year-round, independent of seasonal limitations.

“Since cultures are maintained in a controlled environment, external factors such as temperature fluctuations, pests, and soil conditions do not impact production,” he said. “This can significantly improve supply-chain efficiency for commercial growers.”

Drawbacks are few but considerable

Although TC offers several advantages over  cuttings from mother plants, the method also can have some drawbacks. For one, the practice can be a bit tricky since sterilization of everything involved in the process is crucial. The environment must be cleaned like a NASA lab, as even a single speck of dust, dirt, or debris can cause the culture to fail. This is why many cultivators create a small lab for their TC process and deploy a clean room to ensure no pathogens enter the space. The buildout for such a facility can prove costly, given the equipment necessary.

In addition to the time it takes to perfect the process, tissue culture clones take longer to mature than traditional cuttings. Cuttings taken from a mother plant typically can be planted within two weeks; TC clones often take twice as long. For commercial cultivators on a tight schedule, tissue culture may not be a suitable option.

According to Kalin, acclimating tissue-cultured plants (“weaning”) can pose challenges.

“Since plants grown in vitro lack exposure to natural environmental stresses such as varying humidity, temperature, and soil microbes, transitioning them from sterile lab conditions to greenhouse or field settings can be difficult,” he said. “Special care must be taken to gradually harden them off to ensure survival.”

Despite the potential challenges, tissue culture is a popular propagation method for craft and commercial cultivators alike. And while the concept of TC is hardly new, there is still much to be discovered about its applications in cannabis. With serious concerns about issues like HLVd and the desire to keep up with demand for heirloom genetics, more growers likely will deploy TC as the marijuana market evolves.

“The future of tissue culture looks promising, with technological innovations driving efficiency, affordability, and new applications across industries,” Kalin said. “These advancements will likely make TC even more accessible and indispensable for modern agriculture, biotech, and conservation efforts.”

Cannabis cloning & tissue culture: key questions & expert answers