Genetics 101

All About Cannabis & Hemp Genetics

What Are Clones?

Clones are plants that contain the exact genetic materials as the parent plant they were made from. For example, a cannabis plant that produces a popular version of Purple Haze will have clones that can grow the exact same Purple Haze buds. Since they share the precise same genetic code, cultivators can use cannabis and hemp clones to grow the same products season after season.

Cultivators should on that other factors can influence a plant and its flowers. Even though the clone and its mother have the same genetics, they will only produce the same flowers when grown in similar environments. Someone who plants a clone of the prize-winning Purple Haze could see different yield sizes, potency, and disease resistance when growing it in an environment that doesn’t match the original.

The factors that influence cannabis and hemp cultivation vary significantly. Ideally, growers should follow guidelines to get healthy, profitable plants. If the mother plant generates one pound of flowers while growing in an 84-degree Fahrenheit (29-degree Celsius) room and receiving one gallon of water per day, the clone should offer the same results when grown in that environment.

Of course, cultivating cannabis and hemp clones require more nuance than finding one ideal temperature and water amount. Plants often produce more flowers when their environments provide different amounts of light and water during the planting, pruning, and harvesting stages.

What Are the Differences Between Seeds, Clones, Teens, and Mothers?

Businesses entering the cannabis and hemp industries need to learn terms commonly used by professionals and customers. Some common words include: Seeds, Seedlings, Clones, Teens, Tissue Cultures, and Mothers.


Cannabis and hemp seeds are like the seeds you get from other plants. Seeds contain genetic information that tells the cannabis plant how to grow. Notably, seeds include genes from a female and male plant. Carefully controlled pollination can lead to exciting new cannabis strains. Each seed, however, will contain slightly different genetic information that makes its plant’s traits unpredictable.


Growing cannabis and hemp from seeds requires many steps. First, growers must germinate the seed. During this step, the seed sprouts and begins the process of growing into a plant. Germination can take place in soil, water, or substrates. 

Second, cultivators need to provide the right conditions for growth, including water, nutrients, warmth, and light. Many cannabis growers use highly controllable environments during this stage. Over a few days or weeks, the seedling gets large enough for the grower to transplant it in a larger area. The area can include anything from an outdoor farm to a hydroponics system.

At this point in the life cycle, the plant is very similar to a clone. It will soon grow into a mature plant and grow flowers the growers can harvest, dry, and sell.

Seeds give cultivators opportunities to mix genetics to breed new strains. Unfortunately, it’s impossible to guarantee the sex of a seed. Companies that buy seeds from suppliers can usually expect 99% of the plants to have female genes. Growers should always purchase seeds from reputable suppliers. Even then, no one can guarantee the sex of the plant. 

Cultivators can only reap cannabis flowers from female plants. Hemp growers, however, might not need to control plant sexes as much. Still, most companies recognize that controlling as many factors as possible typically leads to more predictable and favorable results.


Clones are plants that contain the exact genetic code as their mother plants. Growing a clone does not involve any seeds. When cloning cannabis, growers take a “cutting” from a plant with desirable characteristics. Successful cuttings are often branches with a node, the spot where leaves grow.


Cultivators can get clones from a couple of sources. Many companies sell clones from popular plants with traits buyers prefer. For example, a greenhouse might sell a specialized version of Sour Diesel cannabis that has citrus flavors, high THC concentration, and low CBD concentration that many consumers enjoy. When companies purchase clones of a company’s Sour Diesel, they know precisely what qualities the mature plants and flowers will have.


Alternatively, cultivators can make their own clones. When growers find a plant that grows appealing flowers, they can clone it to retain those characteristics for multiple generations. By cloning, the growers avoid additional genetic material that would alter the plant.


Some sellers refer to larger clones as “teens.” Teens have reached a stage in the life cycle when cultivators can plant them and expect the flowering cycle to begin within a few weeks. Like human teenagers, they aren’t fully mature organisms yet. But they are prepared to live in the right conditions without remaining attached to the mother plant.


Most transplants purchased online and in stores are considered teens. Since the term doesn’t have a proper definition, though, it’s always a good idea for buyers to get more information about clones before spending money. Ideally, the cloned transplants should provide a quick return on investment by growing flowers within a few weeks.


Mothers are the parent cannabis or hemp plants that clones come from. In the example above, the original Sour Diesel plant is the mother. Cuttings from the mother plant are her clones.

Successful mother plants often have traits including:

  • Well-developed root systems that fill the pot without sticking to the container, becoming twisted, or forming a spiral.
  • Pest and disease resistance that keep the mother healthy and improve the long-term potential of future generations without using harsh pesticides, fungicides, and other chemicals.
  • Sizes that fit the cultivator’s growing environment (preferences for tall, short, wide, and thin mothers can vary depending on the cultivator’s needs).
  • Flowering potential that encourages larger yields from future generations.
  • Smells, tastes, and effects that get good feedback from customers.

Most cultivators growing their own mothers want to keep the plant alive for as long as possible. A longer life means they can cut more clones from the mother. Typically, cannabis plants only live for one season, which lasts about six months. Professional cultivators can keep mothers alive for up to three years by:

  • Keeping it in a vegetative (non-flowering) stage by exposing it to more than 12 hours of light per day.
  • Pruning (also called “topping”) the plant to encourage robust growth with fewer non-productive stems.
  • Pruning roots by growing them in fabric pots or hydroponic systems and trimming the roots so they do not bind to the container.

Why Would Cultivators Choose Clones Over Seeds?

Clones and seeds have unique advantages and disadvantages cultivators should consider before deciding which option to choose. Many cultivators choose clones over seeds because clones:


  • Guarantee that growers have female plants that can produce flowers.
  • Provide consistent quality by giving growers known genetics that never deviate from the mother plant’s DNA.
  • Eliminate the time needed for seeds to germinate and sprout, thus shortening the time to harvest and helping cultivators earn more money.
  • Improve brand reputation by providing consistent products stores and consumers can rely on.

Cultivators also need to consider the potential downsides of choosing clones over seeds. Some potential disadvantages include:


  • High sensitivity to environmental stressors, which can slow growth and production for growers who don’t know how to provide adequate care.
  • Smaller root systems that can lead to lower yields.
  • Unchanging genetics that make it difficult for creative growers to develop unique strains.
  • Mothers have lifespans that rarely last longer than three years, so cultivators need to give them special attention to prolong their usefulness.

The good news is that professional growers can overcome these challenges. Investing in the right equipment can also encourage faster, stronger growth that makes plants more productive, profitable, and reliable. Today, many grow operations prefer automated systems that can provide precise amounts of water, light, and nutrients throughout all stages of a plant’s growth.


Growers that want to breed unique strains can cross-pollinate adult cannabis and hemp plants. Over time, they can focus on the most appealing traits to grow plants that buyers want. After establishing a new strain, cultivators can use cloning to continue propagating the same genetics without any change between generations.

Should Growers Choose Clones or Seeds?

There isn’t a correct answer to this question. It depends on what a company hopes to accomplish. A grower that wants to maintain control over a plant’s genetics will probably prefer buying or making clones from a reliable mother. The option speeds up the production process and helps ensure high-quality products.


Seeds aren’t as common among large-scale cultivators. Companies with experimental laboratories, however, might want to purchase seeds so they can cross-pollinate cannabis and hemp plants to develop new strains. Controlled experiments make it possible for professionals to choose male and female plants with appealing traits. Each seed created by a female plant will contain slightly different genetic information, though. That means even small experiments can produce dozens or hundreds of plants to try. Most of those plants won’t have qualities superior to their parents. One or two might stand out as exceptional plants that eventually become unique strains.


A company that wants to own a unique strain of cannabis or hemp should use plants and seeds to experiment and test the results. Once they have a strain that appeals to the market, they can use the mother plant as a source for future clones. At that point, the experiment has created a new strain with a single, controllable genetic source.

How Does the Cloning Process Work? The Science Behind Cloning

Agricultural societies have probably been cloning plants for thousands of years to help ensure crop yields and quality. Today, cannabis and hemp cultivators can take a more scientific approach to choosing, cutting, transplanting, and growing clones.

The cloning process always begins with identifying a plant that has appealing qualities. Growers might notice that one plant thrives during an insect infestation while the other plants die. That would catch the growers’ attention, and they might want to clone the plant to avoid crop failures during future infestations.

Cultivators look for several qualities when choosing mothers to clone. Some of the most important traits for today’s cannabis and hemp plants include:

  • Bountiful harvests.
  • Disease resistance.
  • Pest resistance.
  • Appealing flavors and smells.
  • Physical and mental effects that a large number of consumers enjoy.

Wounding and Sticking Clones

When cloning, cultivators can take two steps to encourage successful rooting. First, they should wound the mother plant by using a sharp, clean scalpel to remove a small amount of tissue from a potential clone stem. Many professionals remove 5 centimeters of tissue from the bottom of the clone. This approach often promotes rapid root growth and improves successful rooting that leads to a healthier plant. By removing a section of tissue, cultivators encourage the plant to grow a callus, a non-specialized clump of cells that can turn into specialized cells that develop roots.

After wounding the clone stem, cultivators plant it in a growing environment. Depending on the technique used, the growing environment could be dirt or nutrient-rich water (hydroponic). Cannabis growers often refer to this part as “sticking.” The term likely comes from cannabis enthusiasts who grew clones at home by simply sticking the clone into potting soil. Today, professional growers take a much more technical approach that they can adjust to reach their intended goals.

Growing Teen Clones

Teen clones are very sensitive for several days after sticking. Cutting and wounding the clone promotes growth, but it also causes trauma that can “shock” the plant. Giving the teen clone a gentle environment helps ensure root establishment and healthy growth.


The specific conditions will depend on the plant that someone wants to grow. Generally speaking, clones should spend their first four to seven days in an environment with:


  • 100% humidity.
  • A temperature between 60 and 70 degrees Fahrenheit (16 to 21 degrees Celsius).
  • Light intensity set to 100 μmol·m−2·s−1 (applicable to indoor lighting systems).

The clone should take root within a week. After the roots appear, growers should adjust the environment by decreasing humidity to about 80% and increasing light intensity to 150-200 μmol·m−2·s−1.

Changing Light Intensity and Color

Cannabis and hemp cultivators also need to consider their environment’s light spectrum. Cultivators can encourage healthy root growth by exposing their plants to light that is 5% white, 30% blue, and 65% red. The blue light mimics what outdoor plants would experience during the long summer months when they devote most of their energy to growing leaves and stems.


As the cannabis and hemp plants near the flowering stage, growers should increase the amount of red light they receive. A higher percentage of red light mimics the outdoor environment plants would experience during early fall when they produce flowers and pollen to mate. By increasing the amount of red light and restricting pollen from the grow site, cannabis and hemp plants should make larger flowers.


Reducing the amount of time cannabis and hemp plants receive light also helps mimic the changing seasons. Keeping the plants in darkness or low light for more than 12 hours per day should encourage flower development.

What Are Tissue Cultures?

Tissue cultures are small sections of tissue taken from a mother plant and used in micropropagation. Micropropagation doesn’t require full clones. Instead, the process involves taking tissue cultures and growing them in nutrient-rich gels. Growers must use sterile containers and growing media with the proper nutrients and vitamins for cannabis and hemp plants.


Tissue cultures can come from practically any part of the mother plant, including a root, stem, or leaf. Since growers only need small clumps of cells, they can potentially grow millions of cannabis and hemp plants from one mother. For comparison, traditional cloning techniques can produce 5,000 to 6,000 plants per month. Even a mother that lives for three years will only generate about a quarter-million offspring.


Tissue culture micropropagation is a recent development in cloning technology. Many see it as the future of cannabis and hemp cloning. Some benefits of choosing tissue culture micropropagation over traditional cloning include:


  • More vigorous cannabis and hemp plants.
  • Smaller space requirements.
  • Increased production.
  • Lower costs and higher revenues.
  • Of course, these benefits rely on an experienced grower using a healthy mother plant with strong genetics.

How Do Tissue Cultures Differ from Regular Clones?

Some of the major differences between tissue cultures and regular clones include:


  • Smaller sizes that let growers start with a larger number of plants.
  • The ability to replicate the mother plant more times during her life.
  • More control over the stages of growth.

Cultivators also need to treat tissue cultures differently than regular clones. For example, they would not plant tissue cultures like they do regular clones. Instead, the tissue cultures get placed in sterile containers full of nutrient-rich gels. The gels provide all of the nutrition and moisture young tissue cultures need to grow.


Tissue cultures also create more opportunities for experimentation. A new cannabis business might not know which strains it wants to produce. Tissue cultures let the businesses try clones from several mothers. They can then monitor growth, disease resistance, and other qualities to learn more about which strains match their needs.

Plant Pathogens: What They Are and How to Avoid Them

Plant pathogens include several small – often microscopic – lifeforms that contribute to diseases in plants like cannabis and hemp. Common types of plant pathogens include:


  • Nematodes (parasites also known as roundworms and eelworms).
  • Viruses.
  • Bacteria.
  • Fungi.

Plant pathogens tend to affect specific parts of the cannabis or hemp plant. Common types of pathogens damage the plant’s:

  • Flowers and seeds.
  • Foliage.
  • Stems.
  • Roots.

Pathogens can also attack systems within the plant. Systemic diseases can cause problems like vascular wilt, which prevents the plant’s vascular system from delivering water to cells.

Causes of Cannabis and Hemp Disease

Cannabis and hemp diseases require three factors. First, diseases cannot exist without a plant to host a pathogen. Anyone growing hemp or cannabis already meets this factor. It’s impossible to avoid, so growers need to focus on the other two factors.

Second, environmental factors can contribute to disease. Pathogens often need specific environmental characteristics to thrive and damage crops. Cannabis and hemp growers should pay particular attention to moisture and temperature. For example, too much moisture can encourage fungi growth that damages or kills plants. Luckily, modern growing systems make it easier for professionals to control environmental factors.

The pathogen is the third factor needed to cause cannabis or hemp diseases.



Nematodes are non-segmented roundworms that almost exclusively attach to cannabis and hemp roots, although a few species can affect the stems and leaves. Parasitic nematodes commonly damage root systems by feeding on cells, leading to root rot and other problems that kill plants.



Fungi can cause a broad range of diseases in cannabis and hemp plants. Fungi spores, fruiting bodies, and mycelium threads can contribute to problems like leaf spot, blight, wilt, root rot, cankers, and mildew. These diseases will kill cannabis and hemp plants when left untreated. Even when addressed, the diseases can harm crop yield and quality.



Bacteria are single-celled organisms that can infect organisms. Bacteria can cause odd features in cannabis and hemp plants, including slimy growths that appear overnight. Bacteria can also cause diseases like root rot, stem rot, wilt, fire blight, soft rot, and leaf spot.



Viruses are microscopic pathogens that can attack plants like they attack humans and other animals. Common viruses that attack cannabis and hemp plants include tobacco mosaic virus and tomato ringspot virus. Most viruses damage or kill plants by attacking them at the cellular level, which can lead to growth, reproductive, and immune system problems.

The most common virus impacting cannabis and hemp plants is the Hop Latent Viroid (aka hops virus, HpLVD),  which was a recently identified plant-specific pathogenic RNA. If left untreated, HpLVD can seriously reduce a crop’s potency and yield. Every garden tested in 2019 was infected with HpLVd. Most gardens had an infection rate of about 25-50%, causing an estimated 50 million dollars in losses per year.  HpLVd infections typically occur when an infected clone or plant is introduced into a healthy garden, where it spreads to other plants.

Noticeable symptoms in plants including:

  • Growth stunting
  • Brittle stems
  • Reduced trichomes and oil production
  • Reduced flower mass
  • Malformation and/or chlorosis of the leaves 

Preventing Disease in Cannabis and Hemp Plants

Cannabis and hemp growers often encounter challenges that don’t impact other farmers. For example, government and industry regulations might restrict the types of pesticides, fungicides, and other chemicals growers use to treat plants. Additionally, few cannabis and hemp plants have genes that help them fight infections. Most of today’s most popular strains were cultivated in carefully controlled laboratories, so they never developed natural immunities to diseases, bacteria, and other infections.


Cannabis and hemp farmers relying on outdoor facilities face more challenges than cultivators using indoor facilities. However, some companies prefer outdoor farms because they tend to cost less and produce plants that many consumers find appealing.


Indoor grow operations can also experience problems with fungi, bacteria, viruses, and nematodes. Even when indoor grow operations take precautionary measures, a disease can spread enter the facility from an infected plant. Inadequate growing conditions can also contribute to an infection’s spread. Many grow operations grow plants in multiple rooms to prevent large-scale spread. Employees must follow strict protocols for cleanliness. The company might lose the crop from one room, but it can contain the problem and generate revenues from unaffected plants.

Some critical aspects of preventing disease in cannabis and hemp plants include:


  • Monitoring plants for early signs of disease.
  • Removing plants that show any symptoms.
  • Sanitizing all tools and equipment before they come into contact with plants.
  • Cleaning all pots, water tanks, irrigation lines, and other equipment.
  • Buying seeds, clones, and tissue cultures from reliable sources with high standards.
  • Controlling environmental conditions to prevent excess moisture and heat.
  • Maintaining strict boundaries between grow rooms.
  • Spreading out plants to avoid overcrowding that contributes to disease and helps pathogens spread to other plants.
  • Choosing healthy mother plants that have shown resistance to pathogens.
  • Drying flowers in a separate area to prevent mold, fungi, and other pathogens from affecting the finished product.

Unfortunately, even the most fastidious cannabis or hemp grower’s crop can experience disease. Cultivators must accurately diagnose the disease before they can choose adequate solutions. Some common treatments include organic products that contain active ingredients like:


  • Copper hydroxide.
  • Copper oxychloride.
  • Basic copper sulfate.
  • Copper octanoate.
  • Cuprous oxide.

Concerned business owners and managers can use environmental service consultants and other contractors to diagnose, treat, and prevent diseases before they devastate a crop.

Proper Clone and Teen Transplanting and Care

Clone transplanting and care requires special attention. The specific method growers use will vary depending on their goals, cultivation environment, and the types of plants they have. The following guidelines, however, typically lead to positive results that can help cannabis and hemp businesses succeed.

Plant Clones as Soon as Possible

Ideally, clones should get planted immediately after purchase. Growers should prepare the planting area before they purchase clones. That way, the clones can get planted quickly.


In some cases, buyers might need to store their clones for short periods of time before planting. When necessary, clones can be kept healthy by:

  • Giving them a generous amount of water with a diluted nutrient solution.
  • Keeping them under a low-intensity fluorescent light that will prevent “pre-flowering.”
  • Rearranging the clones so none of them block light from the rest of the group.

Prepare Clones for Transplanting

Start by preparing the media cannabis or hemp clones will grow in. Some media require soaking before use. Coco coir blocks, for example, should soak for about 24 hours before transplanting clones into them. Other substrates might need additives, such as fertilizer, to improve the soil structure before planting.


Teen plants might not have sufficient root balls to thrive in large containers or hydroponic systems. If the root systems seems small, growers can encourage growth by planting them in one-gallon pots for a week or two. Once the clone has a root ball, cultivators can move it to the grow room.

Harden Clones Before Moving Them to Direct Light

Young clones are sensitive to changes in their environment, so growers should limit trauma as much as possible. Clone suppliers typically store their clones in low-light conditions, so they aren’t used to the amount of direct light they will need during the vegetative and flowering stages.

Growers can limit shock by gradually increasing the light’s intensity over a few days. This might seem like wasted time. Why not expose the plants to 18 hours of blue light immediately? Doing so could cause so much trauma that the transplant experiences stunted growth. Plenty of people have limited their harvests by trying to force plants to grow faster than possible.


Farmers use hardening techniques with several types of plants. For example, many farmers will start growing tomatoes inside a greenhouse or hothouse. The structure’s higher temperature lets them grow seeds and transplants before outdoor conditions become suitable for the plant. Before moving the plants from inside to an outdoor field, farmers will gradually expose the young tomato plants to the exterior. They might open windows and doors to allow breezes and sunlight to enter the building. Alternatively, they can physically move the plants outdoors for a few hours per day. After hardening, the plants have been conditioned well enough to recover from the trauma of replanting quickly.

Practice Safety Guidelines for Employees and Plants

All companies should have written policies that tell employees how to stay safe while tending plants. The guidelines should also address ways workers can help plants thrive. For example, safety guidelines should include:


  • Wearing protective equipment when watering, fertilizing, and trimming plants.
  • Sterilizing all equipment and protective gear when leaving a grow room.
  • Reporting any signs of potential concern so an expert can diagnose plants and take action to limit disease.

Monitor Clones Throughout Their Lives

For the most part, professional cannabis and hemp growers should know how to anticipate their crops’ needs. They might have pre-set programs that adjust moisture, light, and temperature to match each stage of growth and flowering. In-soil sensors can even provide real-time data that help growers adjust growing conditions.


Technology certainly plays a critical role in the success of modern cannabis and hemp businesses. However, no amount of equipment can replace the observations of an experienced professional.


Grow operations should have schedules that tell cultivators when to inspect plants. This creates ample opportunities to note potential diseases that could harm crop yields. It also gives cultivators more opportunities to observe their work and make slight adjustments that could improve yield and quality.


It’s important for cannabis and hemp businesses to remember that the legal industry has only existed for a short time. Even small changes to growing techniques could lead to innovations that help companies succeed.

Using CloneSmart to Find Premium Cannabis & Hemp Genetics

When purchasing tissue cultures, clones, teens, or mothers, cannabis and hemp companies need a reliable way to choose products with excellent genes. Until recently, most businesses were forced to rely on the mother’s pedigree. If a mother plant produced large yields of high-quality flowers, companies wanted to buy her clones. Since those clones have the same genetics as the mother, they should also generate successful products.

Now, companies don’t need to rely on pedigree alone. Instead, they can use CloneSmart to find clones, teens, and mothers with premium genetics.

CloneSmart makes it possible for companies to create genetic libraries that list all of the genetic sequences they own. A cultivator that breeds a top-selling hybrid could use CloneSmart to catalog the hybrid’s DNA, enter it into the company’s database, and use the genetic information to create clones.