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How Do I Select Which Cultivar (Strain) to Grow?

A cultivar is a cultivated crop variety that has been produced from selective breeding. In the Cannabis world, cultivars have long been called ‘strains’, similar to wine grape cultivars being referred to as ‘varietals’. The term strain generally refers to unique genotypes of microorganisms, but has been somewhat co-opted by the Cannabis industry.

While there are some Cannabis breeders that truly pursue the production of stabilized genetic lines with unique phenotypic properties, in my opinion, most of the Cannabis strains on the market are produced quickly and have not undergone a long enough selective breeding process to stabilize the lines. Many strains on the market are a result of breeders simply crossing the best sellers of a given season in order to cash in on the hype of particular genetics. This results in most of the products on the market being unstable polyhybrids that have not undergone rigorous breeding on a large enough scale to select phenotypes for traits such as disease resistance that are commonly overlooked.

This is my list for the most important aspects in selecting genetics for your grow:

  1. The most important aspect to consider in microgroweries is whether or not you enjoy the effects of the strain you are growing.
    1. For example, some of my favorite strains of all time have Cherry Pie genetics including GDP and Purple Punch. I tend to get anxiety with sativa-dominant (cerebral) strains and prefer strains with more sedating effects. I also really enjoy strains with high CBD and moderate THC.
  2. Secondly, it is extremely important to choose strains that have been released by reputable breeders that place importance on stable genetics (particularly when growing from seed). If you are purchasing clones, it is important to know that the genotype does not have a strong propensity for hermaphroditism and has phenotypic traits that are favorable.
  3. In an indoor grow, some of the most important phenotypic traits to look for besides the effect of the strain are:
    1. Flowering time (In general, strains that are closer to ‘indica’ on the cannabis spectrum are ready to harvest quickly as compared to plants that are considered more ‘sativa’). I tend to select strains that can finish in approximately 8-10 weeks after the start of flowering. If you are buying seed, one should consider the possibility of growing an ‘autoflowering’ strain. I will go into a bit more detail on autoflowering Cannabis a bit later on.
    2. Yield (Plants that produce large and dense colas are generally preferable when growing on a small scale).
    3. Stature (Height, bushiness, the degree that the plant stretches in flower, and density of branching are all important factors to consider.)
    4. Cannabinoid profile and potency (This may be a very important factor to some. While cannabinoid profile is important to me, I tend to not select my strains on the basis of THC levels simply because most of the strains on the market are too strong for my personal preference, and I do not care much about maximizing THC).
    5. Other metabolite profiles of your plant: Terpenes and flavonoids are important to consider. Terpenes are mainly responsible for the odor of the strain you are growing, but many are psychoactive and influence the effects of the strain you are growing.
    6. Resistance to disease and pests: Different strains have different levels of resistance to various diseases and insect pests. For example, if you have had trouble with powdery mildew in the past, it would be useful to avoid strains that are particularly known for powdery mildew susceptibility.
      1. In my last grow, I had three strains in one grow tent (Dream Queen, Purple Punch, and Venom OG). I had a whitefly infestation occur, and I noticed an obvious difference in whitefly populations on the different strains. Dream Queen had very few whiteflies, while Venom OG seemed to have the most.
      2. For Powdery Mildew, it appears that the most resistant strains have Afghani heritage, please see my post on PM under pest and disease profiles for strain recommendations.
      3. For bud rot, it appears that the most resistant strains are equitorial sativas. Please see my post on bud rot under pest and disease profiles for strain recommendations.

As you can tell, indoor growing really lends itself to strains that have classically been considered ‘indica heavy’ and have a short, bushy stature, quick finishing time. Although plants with a more ‘sativa’ phenotype can be grown indoors, they tend to be more difficult because they are more lanky, they tend to have a longer internodal spacing, they stretch a lot during flower, buds tend to be less dense, and the time to finish can be quite long. However, there are techniques to help keep these plants more manageable such as training. Do not let yourself be deterred if you are set on growing such a strain.

If you are new to Cannabis and do not have a firm grasp on your strain preference, I would do the following to select a strain to grow:

  1. Look for local vendors selling cannabis clones and look through their offerings. Select at least a few of the strains (some indica dominant strains, some sativa dominant strains, and some hybrid strains).
  2. See if there are any dispensaries in your region selling flower of your selected strains and purchase a small amount of each of the selected strains.
  3. Sample the flower on different days and select the one with the effects you enjoy the most for purchasing clones. Often times, the dispensaries in the region may not have the flower of the strain you want to sample. In that case, it might be worth doing some searching for the offerings of local dispensaries and only selecting strains that you can purchase clones for.

I believe that for first time growers, it is best to grow from clone as opposed to seed if you have access to them. The reasons for this include: genetic uniformity between plants and phenotypes that have already been selcted for favorable traits. When you buy seeds, as I mentioned earlier, many strains are not stable and can produce a variety of phenotypes, some of which may be unfavorable. It is best to have a bit of experience in finding trusted breeders before buying seeds. However, with a bit of web searching, you can find some well-reviewed genetics from trusted breeders. If you are buying seeds, I believe autoflowering seeds tend to be the easiest beginner plants to grow; you will not need to change the light cycle to induce flowering, they finish quite quickly, and you do not need to fuss about physical manipulation techniques such as ‘topping’, ‘FIMing’, trellising, or other training techniques. Though historically considered to be of lesser quality, autoflowering Cannabis has come a long way and there are many strains out there that produce high quality flower.

What to Look for in a Clone Nursery

Due to my location, I have only ever bought my clones from one source: Dark Heart Nursery (with the exception of when I was running Ken’s Cut GDP for a while). Dark Heart is a very reputable nursery that puts a lot of care into their strain selection, and most importantly for me, they produce disease-free clones. They have a dedicated Plant Health Department that ensures operating procedures are kept as sterile as possible, and they go through the necessary steps to ensure that their clones are free from known viruses and viroids. The causal agent of cannabis ‘dudding’ disease was discovered and described as the Hop Latent Virus by their plant health department and necessary steps were taken to ensure the viroid was eliminated from all plants [1].

It is important to select your clones from a nursery that takes care to ensure they are providing healthy, disease free clones.

How Do I Select a Reputable Breeder?

In my opinion, if you are not going to test out seeds or cuts from various different breeders, the best way to find reputable breeders is to read forums discussing the topic.

One of my favorite strains of all time that I kept in production for multiple years was Ken Estes’ Granddaddy Purple. I personally do not have a ton of experience with trying a large variety of breeders, but I have also had success with Greenhouse Seeds (I did a few runs of their Bubba Kush).

Purple Punch is a favorite of mine, and though uncertain, breeders at Supernova Gardens claim to have produced this legendary strain. Often times, the breeder of well-known strains are debated and the actual crosses that occurred are unknown as well. In such cases, you generally will grow the strain because it has a reputation of being high quality regardless of the breeder. One such strain I have grown is Dream Queen, though the genetics I grew came from the highly reputable Humboldt Seed Co.

I enjoyed growing Venom OG from Rare Dankness, but as with many ‘OG’ strains, it was a bit lanky and the buds were a bit loose for my liking. However, I enjoyed the diesel odors, rich colors, and effects of this strain. One of the most reliably consistent seed-grown strains I have ever run is Skunk #1 from Sensi Seeds. Though the strength of this strain is mild to moderate, I enjoy the lower THC content, the consistency of the plants, the hard to come by skunky odor, and the yield. Sensi Seeds has a lot of very stable strains that I enjoy, and they don’t seem to play the THC-hunting game or the name game so prevelant in today’s Cannabis culture. Their Big Bud is also a nice strain to grow. It produces well, is not overly powerful, and is very forgiving to the new grower.

I am also a big fan of Barney’s Farm. Though I cannot speak to all of their products, I grew their LSD one time. It yielded well, had no issues to speak of, and I enjoyed the moderately strong but relaxing effects. I would grow this strain again.

In terms of autoflowering plants, I have ever only tried Blueberry Auto by Dutch Passion Seeds. By introducing ruderalis genetics to DJ Short’s legendary Blueberry genetics, they have managed to produce a plant that yields very well, finishes very quickly under long day conditions, and is fairly potent with a nice nose, which can be difficult to achieve with autoflowers.

Aside from the breeders/seed companies mentioned above, popular seed companies in forums include DNA Genetics, Bomb Seeds, Sin City Seeds, Buddha Seeds, Anesia Seeds, and Royal Queen Seeds. These are all companies I see popping up in forums (recently I have seen a lot of praise for Sin CIty, Buddha, and Anesia in particular). I have not tried anything from them.

What is the Takeaway?

There are so many strains out there it can be overwhelming to choose. The bottom line is you should choose a strain that you enjoy consuming, but other factors (mainly yield and finishing time) should come into play in choosing between strains you like. Buy your seeds from a reputable breeder/seed company and buy your clones from nurseries that ensure you are receiving a healthy plant.

If you don’t know where to even begin and don’t want to sample a bunch of cannabis, simply choose any of the companies I have mentioned above and buy a product with positive reviews, go on Leafly and determine if the described effects are desirable to you, and just do it. When it really comes down to it, it’s hard to go wrong.

  1. Warren, J. G., Mercado, J., & Grace, D. (2019). Occurrence of Hop Latent Viroid Causing Disease in Cannabis sativa in California. Plant Disease, 103(10), 2699.

Cannabis Pest Profile: Whiteflies

What is a Whitefly?

The most common cannabis pests are those with the physiological capability to bypass plant trichomes with piercing-sucking mouthparts. Such insects include aphids, leafhoppers, and whiteflies [1]. Whiteflies are annoying little pests that are related to aphids (in the order Hemiptera). They feed on the sap of plants, which is a sugar-rich solution transported in the plant phloem.

What Species of Whitefly affects Cannabis?

The most common whiteflies found in indoor grows in California have a wide host range and are mostly classified into a few species: Bemisia tabaci (sweetpotato whitefly), aleurodes vaporariorum (greenhouse whitefly), and silverleaf whitefly (Bemisia argentifolii) [1]. There are many more species of whitefly that may potentially affect Cannabis. However, control methods are largely the same between species.

What is the life cycle of a Whitefly?

Whitefly life cycle

Illustration adapted from M. L. Flint. July 1995. Whiteflies in California: a Resource for Coop. Ext. UC IPM Publ. 19.

The length of time for a whitefly to mature differs between species (32 days from egg to adult for greenhouse whiteflies, 39 days for silverleaf whiteflies [2]). After hatching, whiteflies must progress through four nymph stages and a pupal stage before becoming adult whiteflies. An adult whitefly can live between one and two months, though different species have different lifespans. Whiteflies tend to lay eggs and spend most of their early development underneath leaves. However, nymphs and adult whiteflies can often be seen in high concentrations on top of Cannabis leaves as well. Whiteflies reproduce most prolifically in warm weather, though I have also had a whitefly outbreak occur in a grow tent that was in the garage during winter. It got quite cold during the nights (50 Farenheit), which for the record, is not ideal for plants either.

What Danger do Whiteflies Pose to my Plants?

Whiteflies can cause direct mechanical damage to your plants. They feed by piercing plant tissue and in high populations, they can cause yellowing (chlorosis) of leaves and even leaf death [3]. Generally damage caused by feeding alone is mild unless populations are very high.

They also cause indirect damage. As whiteflies feed, they exrete excess sugar-rich liquid onto plant leaves known as honeydew. Honeydew can attract other insects such as ants, and can be a substrate for sooty black mold to grow on leaves. Sooty mold and honedew can negatively impact photosynthesis. Furthermore, whiteflies are known to transmit many plant viruses. Though viral Cannabis diseases have not been heavily researched, a 1971 study found that a majority of screened common plant viruses can infect Cannabis [4]. Greenhouse whiteflies have been reported as some of the worst vectors for viruses that can infect Cannabis [5]. Please see my post on Cannabis viruses under pest and disease profiles to learn about what viruses may be transmitted by whiteflies.

What Can I do to Prevent and Treat Whitefly Infestations?

Environmental Conditions

As mentioned, whiteflies do best in warm, humid weather. An indoor grow tent provides perfect conditions for whiteflies to reproduce. Keeping your grow area cool is one way to help, but Cannabis grows best at warm temperatures as well, so you will be stressing your plants and inhibiting growth by doing this. My rule of thumb is to keep your grow area in the low 70s (Farenheit). Humidity should be controlled not only to inhibit the proliferation of insect pests, but also microbial pathogens. My personal preference is to keep the relative humidity of my growing space around 40%, certainly no higher than 50% (for mature plants only, seedlings may require high humidity).


Cultural methods: Keep your grow area clean. Do not bring plants into your grow area that have been kept outside. Sterilize all tools used in the grow area with 70% isopropanol or ethanol. Be sure to clean the inside of your grow tent before introducing new plants, remove all plant debris from the area.

Physical control methods: I like to use reflective mulches in all my grows. If you are doing indoor container gardening, a simple method is to make a carboard cutout that sits inside of your pot, on top of the soil. Make sure to cut a hole in the center for the plant stem, and cut a small strip from the outside of the collar to the center so that you can slide it around the plant stem. Finally, wrap the collar in aluminum foil and slide it around your plant stem. Reflective mulches can repel invading insects and provide more light to the underside of plant leaves which is also beneficial to plant photosynthesis. Furthermore, it helps control other insect pests that utilize the soil to complete their life cycle, and helps maintain soil moisture and temperatures. Collars should be removed for watering and feeding of plants.

Chemical prevention methods: Neem oil is the hydrophobic extract of the seeds of the neem tree [8]. It is typically bought as an extract of 70% neem oil. I advocate using neem oil sprays even before encountering any insect or fungal issues with your plant. I recommend spraying your plants once every two weeks up until flowering is visible. I do not use neem oil after flowering begins because it can affect the taste and the smell of your buds if it gets on flowers. Furthermore, neem oil can cause allergies in some, and has been shown to be a potential toxin to humans when consumed [6]. I would recommend using neem oil only on healthy vegetative plants.

To spray plants, you will need a one-hand pressure sprayer. I like to use 2 Tbsp of neem oil per gallon of water and I add a couple of drops of dish soap to help emulsify and spread the neem oil. Always test one leaf of a new cultivar/strain you are growing before spraying the whole plant by soaking a single leaf in your prepared neem oil solution. Check in a 24-48 hours for any adverse reactions. Spray your plants at night time only, and be sure that there are fans on your foliage to ensure that the solution dries before your lights switch back on. It is important that the solution dries because lights can easily burn your leaves if they are still wet, especially with a neem oil in it. I also like to rinse my leaves 3 days after the last spray. First off, it helps remove extra fats and oils that are just sitting on your leaves, and secondly, it can help rinse off any potential insect eggs. It is a good idea to use a spray bottle that you only use water in to do this. Do not rinse your leaves frequently as this increases risks of foliar diseases developing. Only do this every other week, three days after your neem oil application.

Another good leaf rinse besides water is a citric-acid based rinse such as Nuke Em by Flying Skull. Doing a weekly or biweekly leaf rinse with such a product can help prevent insect outbreaks as well as powdery mildew outbreaks. I cannot recommend this enough. You could even use this rinse instead of the water rinse after your neem application.

Because indoor grow tents tend to be isolated, natural predators of pests are not present to help control pest populations. Releasing lacewing larvae and/or ladybugs in your grow tent can be a good idea soon after planting to help reduce any potential pest populations before they get out of control. You must be aware that you may need to alter your spray program if you are introducing beneficials as many pesticides will also kill your beneficial insects.


The most important thing after prevention is monitoring. If you have taken proper preventative measures and you still notice a growing population of whiteflies in your grow area, it is time to be more aggressive. At first sight of whiteflies, prune and remove infested leaves from your growing area.

Chemical Control Methods

Insecticidal Soap [7]

At this point, it is a good idea to spray down your plants with insecticidal soap. However, if your plant is in flower, do not spray your buds with insecticidal soap. Though safe, the soaps may affect the taste of your buds. Insecticidal soaps will also kill beneficial insects, so it is not recommended to use insecticidal soaps if you are utilizing beneficials. Always test the sprays on a small portion of the plant before spraying the entire plant.

Neem Products [8]

If an infestation is in progress, I personally like to swap out neem oil for an azadirachtin product such as Azamax. If you continue to use neem oil, begin applying on a weekly basis as opposed to a biweekly basis. Azadirachtin is the most active chemical found in neem oil, and I find it to be more effective than just neem oil. Azadirachtin is OMRI certified. It can become systemic in the plant and has low toxicity. However, there have been negative effects reported from neem products in some people, and so I would recommend not to use any neem products on your plants during flower, and certainly not during the last 4 weeks before harvest. If you are growing cannabis to sell it or give to others, I also do not recommend using neem products as some people may have allergies. I have found this pesticide to be very reliable in getting rid of whitefly infestations (as well as certain spider mites). This product will also kill most whitefly predators, with the possible exception of ladybugs, so it is not recommended to use this product along with beneficials.

Citric Acid Products [9]

My chemical of choice would have to be a citric acid based pesticide such as Nuke Em by Flying Skull. Citric acid pesticides are OMRI certified and very effective at killing whiteflies. They are nontoxic, and can be sprayed directly on buds without worry of altering the flavor or smoke of your bud. In my personal experience, this should be your go-to chemical product if you are worried about using neem products at all. I would recommend reapplication every 5 days until the infestation clears up. It would be useful to have a one-hand pressure sprayer for application.

Pyrethrin Insecticides [10]

Pyrethrin insecticides can be quite effective, but I would not recommend using them at any point during the flowering cycle of your plant as they are toxic to humans as well as insects. I would recommend to stick to neem and citric acid products.

Spinosad Insecticides [11]

Spinosad is composed of two bacterial-derived chemicals that are toxic to a wide range of insects. It can be quite toxic to beneficial insects as well as bees, and so I recommend spraying at night and only utilizing it if necessary (especially if you are venting to outside). It should not negatively affect beneficials if they are released after the spinosad completely dries. However, it is nontoxic to humans, the label claims that it can be used safely up to the day before harvest (though I would not spray this on flowering plants as according to the UC IPM website for whiteflies [3]) and can be useful in a microgrowery IPM program if you are not using beneficials. Spinosad can be quite effective at killing whiteflies.

Beneficial Insects

Beneficial insects can be very effective at controlling whiteflies. Often, whitefly populations only get large due to the lack of natural predators present in greenhouse and grow room operations. If you are growing inside and do not want a lot of insects flying around, this may not be the best option. However, if you want to avoid using chemical control methods, this can be an effective replacement. If you are using chemical control, beneficial insects can be used in conjunction with certain sprays to maximize your pest suppression.

Green Lacewings

Green lacewings (Chrysoperla rufilabris) are particularly effective at controlling populations of soft-bodied insect pests. Adults are not predatory, but their larvae will feed on whitefly eggs and nymphs [12]. If you are not using sprays in your IPM program, it is a good idea to release lacewing adults early in the vegetative stages. You must provide the adults with flowers so that they can feed on nectar and pollen (spring-flowering plants for vegetative growth, fall-flowering plants for your flowering cycle) [13]. They will lay eggs and newly hatched larvae will help control pest populations. Alternatively, if there are already pests present in your grow room, you can release green lacewing larvae directly to address the infestation. If you want to maintain your lacewings, you must add flowers for them to feed on when they mature.

Whitefly Parasitoids

Encarsia formosa (for greenhouse whitefly) and Eretmocerus eremicus are two commonly used parasitoids of whiteflies that lay their eggs in whitefly nymphs, eventually causing the death of their hosts [14]. They are selective and highly effective at addressing large populations of whiteflies and should be released in the case of a heavy infestation.

Combining Chemical and Insect Control Methods

The only chemicals I would recommend combining with insect releases are neem oil and citric acid-based sprays. At the first sign of an infestation, begin with a wash of insecticidal soap. Following this, apply a neem or azadirachtin spray to your plants. 3 days following this, rinse your plants with water followed by a citric acid-based pesticide. After your plants dry completely, it is safe to release your beneficial insects. Do not apply any other sprays for at least 2 weeks after releasing your beneficials. If you are still experiencing an infestation (which is highly unlikely), I would recommend trying a spinosad insecticide.

  1. McPartland, J. M. (1996). Cannabis pests. Journal of the International Hemp Association, 3(2), 52–55.
  2. Whiteflies in the Greenhouse. (n.d.). Retrieved February 5, 2020, from
  3. Whiteflies Management Guidelines–UC IPM. (n.d.). Retrieved February 5, 2020, from
  4. Hartowicz, L. E. et al. 1971.  Possible biocontrol of wild hemp. North Central Weed Control Conference, Proceedings 26:69
  5. A review of Cannabis diseases. (n.d.). Retrieved February 5, 2020, from
  6. Meeran, M., Murali, A., Balakrishnan, R., & Narasimhan, D. (2013). “Herbal remedy is natural and safe”–truth or myth? The Journal of the Association of Physicians of India, 61(11), 848–850. Retrieved from
  7. The Dirt On Insecticidal Soap | Garden Safe. (n.d.). Retrieved February 7, 2020, from
  8. Neem Oil General Fact Sheet. (n.d.). Retrieved February 7, 2020, from
  9. EPA Office of Pesticide Programs, U. (n.d.). US EPA – Pesticides – Fact Sheet for Citric acid and salts.
  10. Pyrethrins General Fact Sheet. (n.d.). Retrieved from
  11. Spinosad General Fact Sheet. (n.d.). Retrieved February 7, 2020, from
  12. Green Lacewings for Aphids. (n.d.). Retrieved February 7, 2020, from
  13. Grow Hack: Use Green Lacewings To Eat Or Prevent Nasty Pests • High Times. (n.d.). Retrieved February 7, 2020, from
  14. Liu, T.-X., Stansly, P. A., & Gerling, D. (2015). Whitefly Parasitoids: Distribution, Life History, Bionomics, and Utilization. Annual Review of Entomology, 60(1), 273–292.

Why Grow Cannabis?

My Homegrown Purple Punch

Cannabis is no longer a subculture, it is pop-culture

— Jorge Cervantes

Growing Cannabis at home has many advantages. Unlike most crops, Cannabis can be grown on a small scale at home far more economically than buying it at a dispensary or on the street. If you grow it yourself, you know exactly what is going in to your Cannabis, and you are far more connected to the Cannabis you smoke.

Besides the obvious benefits, Cannabis is a true joy to grow. It is not very finicky as far as plants go, it is absolutely gorgeous to look at, and the smell of fresh Cannabis is wonderful. You can utilize almost the whole plant: flowers for smoking or extraction and trim/leaves for extraction.

Of course, growing Cannabis has some drawbacks. For one, growing Cannabis is a bit more work than buying it from the store, but if you fall in love with the process, it hardly feels like work. Smell can be an issue for those trying to be discrete, and so precautions must be taken for odor control. There is risk to growing any crop, because it takes financial input for growth and there is always the risk of losing plants to pests, disease, or environmental issues. These are all issues I hope I will be able to provide some guidance on to maximize your potential as a home grower.

I hope I can share my love of Cannabis with you, and some information along with it. It is not as hard as you might think, especially with a bit of guidance.

Who Am I?


  • I have a Masters of Science degree in Plant Pathology from UC Davis and currently work for a Cannabis farm in California as the manager of IPM (Integrated Pest Management). We run a high turnover, year-round hoophouse-based system. We grow high quality outdoor soil-grown plants and maximize the usage of safe biopesticides with beneficial insects and mites.
  • I have been home growing indoors for 11 years now, starting off in my undergraduate years in college (I received a B.S. in Biochemistry)
  • My hobbies include growing mushrooms, growing Cannabis, growing cacti and psychoactive plants, and growing fresh food.
  • My philosophy on agriculture is based on regenerative practices, soil health, and ethical stewardship of land and livestock.
  • I feel as if I can bring a unique perspective to educate the general public regarding disease and pest control in Cannabis and basic techniques for microgroweries.
  • Home growing cannabis is undergoing a boom, and people are hungry for knowledge and how to address the issues their plants are facing.
  • Cannabis is a fascinating plant; more research is published frequently, and I believe I can be of service in communicating some of the research to those searching for knowledge.

Opening questions

  • Why are you blogging publicly, rather than keeping a personal journal?
    • This is meant to be a resource of information, and I would like to help others achieve their goals of home growing
  • What topics do you think you’ll write about?
    • I will cover home growing techniques and products that every home grower needs to know.
    • I will communicate the latest in cannabis research, focusing most on information that will be useful for growing cannabis, specifically pest control, lighting, and nutrients.
  • Who would you love to connect with via your blog?
    • Home growers, farmers, plant pathologists, and everyone interested in cannabis.

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