How To Select Cannabis Clones

A great cannabis crop from cuttings starts by selecting vigorous strains, choosing healthy clones, and providing them proper care.

Cuttings from a mother plant develop roots in a clone machine that uses aeroponics.

Growing cannabis from clones is a common method of propagation because cuttings from a female plant will also be a female, it is reliable in that plants typically start at the same size, and predictable since genetics of the mother plant are the same, and desirable because of known characteristics of the strain.

“Clone propagation affords consistency in production farming from the genetics of the mother plants, the known sex, similar sizes at the same start date, and ease of portability. ”

If you purchase clone stock from a reputable source or produce your own from mother plants, some basic principles will help achieve optimal rooting and vegetative growth.

The Benefits of Clones

Growing cannabis from clones is a common method of propagation because cuttings from a female plant will also be a female, it is reliable in that plants typically start at the same size, and predictable since genetics of the mother plant are the same, and desirable because of known characteristics of the strain.

There is obviously more than one starting method to begin a medical marijuana cultivation project, affording various options of timing and control. Each method has merit so cannabis farmers must rely on preferences based on their own operation and culture methods to choose starting by seeds, starting with small plants in nursery cups or one (1) to five (5) gallon containers, or with cuttings commonly called clones.

In very basic terms, cloning cannabis is largely by stem cuttings rooted in “clone machines” using aeroponics for rooting as depicted, in a substrate like rock wool or floral foam, or in nursery cups containing coco coir mixes. The use of clones provides an exact replica of the qualities and characteristics of the parent stock, where female plants are the donors of the genetic material for crop production of desirable strains. The technologies, equipment, and supplies available for cloning today are numerous, resulting in superior methods and a premium stock, right along with tons of choices for medical marijuana growers.

Choose Wisely

Of the many important tasks associated with the beginning of a grow is the selection of the seeds or young plants, especially for the production farmer who cannot afford a poor choice of strain or quality. While good data on percentages of farmer start methods are not easily available, the trend to start with clones, or stock propagated from select mother plants, is increasing as more clone nurseries open, expand, and offer desirable strains. The advances in hydroponic technologies and an increase of practicality for indoor cultivation are also increasing the demand for clones.

Unless you propagate your own stock from selected female plants that you start from the seeds or even other mother plants, it is necessary to spend ample time planning to gain the advantages of purchasing cuttings for production stock. To fully maximize the benefit from using clones to start a crop, first research the various strains, find a quality propagator for sourcing, and use the correct cultivation protocol suitable for cannabis clones until permanently planted for ideal growth and subsequent bloom.

Pick What to Grow

The first step to crop success with clones is deciding what strain to cultivate based on the grow location (indoors, greenhouse or outdoors), ease of cultivation, plant dimensions when mature, yield and marketability of the harvested crop. Other factors like the planned final form for consumption (flowers, concentrates, edibles, vape pens, topical products, etc.) may also influence your strain selection. As distribution streams vary by location and consumer preferences are often guiding what clone nurseries propagate, availability might ultimately determine your choices, so a list of alternatives forms a useful sourcing plan. With more than 750 known strains and new ones created regularly, selection is wide and deep.

Since regional preferences will play a role in your decision on what to grow, good resources for assistance in strain selection are local dispensaries or legal retailers and clone nurseries. Although no one can predict precisely what will sell well down the road, current market trends are an excellent guide as you research the many pure and hybrid strains now available. 

There is a wealth of information available on the internet about most named cannabis plant varieties, including the preferred climate ranges, height and width characteristics, flowering times, yield, etc. Sites like describe the nose, taste, and effects, while seed vendors usually go into depth on the origins of most with cultural requirements for optimal growth. Individual dispensaries and stores that sell legally usually have websites that provide awesome images and accurate descriptions of flowers and derivative products; important tools as you make your decision on what to grow.

For even more useful data, visit your local sellers, and purchase a consumable product derived from what you are considering to cultivate. Experienced cannabis farmers will tell you that if you enjoy what you grow, your chances of cultivation success increase, so include sampling in your evaluation process; tough work but always worth it.

There are numerous advantages to purchasing clones from reliable sources instead of producing your own since clone propagation adds additional time to a grow project and if done properly, requires expertise, the proper equipment, and the facilities to produce quality stock, economically. There are also advantages to producing your own clones, especially with a wide selection of cloning machines on the market. Models include those with various site sizes using aeroponic, hydroponic, and deep-water systems, and even kits to build your own are available. For clone propagators, commercial sizes are also now available.

Sometimes growers will grow their own mother plants started from seeds for cloning their own production stock, usually for absolute control that avoids contamination issues like systemic action from a substrate or exposure from other sources. Other reasons include growing a new or exotic hybrid that is only available as seed or for their own hybridization and breeding programs. With many options available for cannabis clone use, either from a clone producer or from your own propagation program, the doors are wide open to tailoring a system that works best for your individual farming operation.

“Regulated markets that require licensing or have a permit process often restrict how many clones are available to the noncommercial grower. Usually, laws or regulations are specific about the plant numbers allowed in cultivation by individuals and most have other limitations also.”

Find a Supplier

Your best resource for cloning machines and supplies like extra collars or rooting compounds are hydroponic stores, but for growers who purchase their clone stock, an important step for growers who begin with clones is to find a reputable clone nursery or seller of stock that came from one. In some places, regulations define the path of clone to the grower, in other places where markets are developing and where tracking may not exist, it is like the wild west, with the possibility of crazy names and questionable labeling.

A gloved technician holds the base of a clone showing emerging roots.
Healthy, white roots emerge from a rock wool cube indicating the clone is ready to plant.

Wherever a grow is located and despite any lack of rules, make certain that you start with clones that came from reliable propagators. They are out there; ask at hydro stores you patronize or local dispensaries that sell seeds or nursery stock for guidance, or shop until you are sure.

Pricing varies according to the strain, the size, or maturity of the clone or the type and size of the rooting media. Do not underestimate the real value of quality clone stock. It may cost more than the average, but saving a few bucks on clones is often the worst criteria for making a purchase. Instead, ask for any available discount for quantity or volume purchasing, especially if it is a hybrid you really want to grow. 

Within a competitive marketplace, it is very common for clones in high demand to be subject to selling out before you have an opportunity to look at them. In Spring months, the challenge worsens. To get around this, some clone growers or sellers provide drop-alerts by email for specific strains and some offer reservation or pre-order systems. As a rule, desirable clones do not last long on the shelf, so if available, buy them if you want them, sooner than later.

Some sellers of clone stock have minimums, some sell only what they select for you and others allow individual clone choice by you. If you choose your own, look for healthy sturdy stock with white roots just starting to emerge at pot bottoms, horticultural foam or rock wool, sides as depicted in the image. Handle plant material with nitrile gloves and protect your purchases from direct sun or temperature extremes until you arrive at your project site.

Quarantine New Arrivals

Unless you propagated your own clones, you must assume that there was a risk of exposure to pests, chiefly mites, during transportation or in the selling environment. Even stock that came from a top clone producer is vulnerable, so isolating any new stock for about ten (10) days is a prudent step in protecting your facility or other stock from pests that might be on your new entries. For most pests of concern, ten (10) days allows the completion of life cycle stages for identification and treatment.

If clones are mature, and roots are starting to emerge, it is possible during the quarantine period to transplant them into larger growing containers, such as four (4) inch pots or one-gallon containers with a substrate like that which will accommodate them for growth to maturity after permanent planting, using hygienic methods and top-quality supplies. There is a space advantage to keeping an interim container small, and there is a reduction of water and nutrient solutions required until permanently planted. Use good labeling practices for each plant, especially if growing more than one variety and use labels that can safely follow each clone from transplanting up until cutting down the plant after flower removal. When possible, double labeling, with one attached to the plant trunk and one on the container, further helps avoid misidentification errors at harvest time.

During a quarantine period up until permanent planting, it is very important to keep the clones hydrated; keep the substrate moist but not saturated as air space is vital for root development and plant health. Provide static temperatures in the 68˚ F to 78˚ F temperature range and humidity in the eighty to ninety (80 to 90) percent range using plastic domes or hoods, with twelve to twenty-four (12-24) hours of suitable (fluorescent is common) lighting per twenty-four (24) hour period. Make sure that heat from any light fixture does not reach the tops of plants that may scorch easily by providing adequate space between the light source and the plants. Plant spacing affects how light penetrates to lower plant portions, a factor that influences early stages of branching and leaf formation. Proper distances between clones allow good air circulation while small clip-on fans located near the clones, help facilitate good air movement while discouraging fungal diseases, but keep direct airflow off foliage to reduce a risk of dehydration.

Neem oil and Azamax® are effective agents against many pests, especially spider mites that attack clones, providing you use a dilution rate applicable for tender seedlings at intervals suggested by the manufacturer. Read and follow all labels carefully since all products are not the same. Once a quarantine period is complete and you are certain there are not pests or diseases present, place clones into their permanent growing substrate and space.

Initial Nutrition and Climate

Clones respond well to nutrient delivery by solution, in formulations and dilution rates suitable for seedlings, even after transplanting. High levels of nitrogen, potassium, phosphorous or products diluted incorrectly will cause serious harm to tender plants; better to err on the side of a weak solution than one that is too concentrated for clone fertilization. Water and nutrient solutions for young clones are best in the 6.0 to 6.8 pH range for soils and 5.5 to 6.5 pH range for soilless media.

If you are planting clones outdoors or in a greenhouse that is more than ten (10) to fifteen (15) degrees cooler or warmer than the quarantine environment, or is much drier, it is very important to offer climate protection or modification to prevent shock or damage to tender plant tissues that do not respond well to environmental extremes or wide swings in temperature and humidity. A period of hardening off for new sprouts often utilized by vegetable growers is also very beneficial for any young cannabis plant, but especially for clones. How you accomplish that control depends on your individual location and setup, but a major factor requiring planning beforehand for rapid and vigorous growth of new clones and the top yields at harvest time.

With some investigating, resourcing, and a little planning, the use of cannabis clones for cultivating medical marijuana will be a successful endeavor offering consistent and reliable production for today’s progressive grower. Start now, choose what you like, find premium stock, and then use sustainable methods on a direct path to a bountiful harvest.