cannabis strains

Mixed Greens: How To Grow More Than One Cannabis Strain At The Same Time

One of the basic decisions you’ll make as a cannabis grower is whether to cultivate one strain, or multiple strains together at the same time. Ultimately, your decision will be based on whether you grow from seeds, clones, feminized seeds or non-feminized seeds.

Especially in licensed commercial grow ops, growers want plants that are uniform in phenotype, physical structure, nutrient needs, gender, growth characteristics, height and bloom-phase length. Cultivating only one strain at a time from clone promotes efficiency and saves labor, and you can count on clones from the same mother plant to grow the same way at the same rate and reach the same height with the same structure. They’ll also require the same feed program, will all be female, and they’ll all have the same resistance to pests and diseases. Plus, they can all be harvested together.

In contrast, even the most well-bred, stable cannabis crop grown from seed shows phenotype variability. If you’re cultivating one strain from high-quality feminized seeds, you may see two or more phenotypes, while if you’re growing from high-quality non-feminized seeds, you might see two or more phenotypes and about half your plants will turn out to be male.

Based on choices you make, your grow op can give you the following range of variability in crop development and outcomes:

  • At the lowest end of the variability range is clones grown from one mother plant. More variability will come when growing one strain from feminized seeds.
  • Following that is growing non-feminized seeds of one strain.
  • On the higher end of the variability scale is when you grow clones from several different mother plants of different strains, or grow seeds of several different strains. You’ll get plants of all shapes, sizes, growth rates and bloom-phase timing, greatly increasing the amount of work and workarounds you have to perform in your cannabis grow op.

Now, let’s look at the additional challenges you’ll deal with if you grow multiple strains instead of just one:

  • Grow-phase length for different strains will vary.
  • The need for and timing of topping and training for grow-phase plants will vary widely.
  • Grow- and bloom-phase hydroponic feeding parts per million will vary, depending on strain.
  • The ideal time for starting bloom phase will vary.
  • Development of early budding sites and the maturation flow for buds will be vastly different, strain to strain.
  • Bloom-phase feed programs will be a challenge, because different strains mature at different rates, which influences your four bloom sub-phases and thus your ideal feeding program.
  • Plant height won’t be uniform, necessitating adjustments to ensure that all plants are evenly lit, and that none are burned by grow lights.
  • The need for and type of plant supports in bloom phase will vary, with some strains needing help due to branch-bending fat buds.
  • Timing of implementing the end-phase cannabinoid and terpenoid feeding-lighting-flushing enhancement program will be different, based on strain.
  • Harvest timing will fluctuate.

Logistics And Adjustments In Mixed-Strain Cannabis Grow Ops

Clearly, a multi-strain grow op requires extra work and skills. When I run such a garden, I have to mix different feed programs for each strain and administer nutrients separately to groups of plants, especially as I implement my precision feeding program that takes into account the four bloom sub-phases. This sometimes adds an hour or more onto my daily crop-tending labor and requires extra brainpower to figure out dosing for each strain.

In an outdoor grow op where some strains have natural terpenoid defenses to keep them from playing host to garden pests such as spider mites, thrips and aphids, plants from other strains will likely act as magnets for such pests. In these instances, I’ll use systemic and foliar spray inputs to deter and control garden invaders, so the differential between pest-resistant plants and plants that are susceptible means different feed programs and foliar sprays. I also must take into account wind direction, because I don’t want the pest-deterrent foliar sprays to blow over onto the buds of my pest-resistant plants.

Perhaps the most impactful differences in a multi-strain, multi-phenotype garden is in plant structure and height. Although there are good reasons to grow multiple strains in the same garden, I’ve often felt concerned by the logistical nightmare of having indica strains that naturally grow four-feet high in the same room as sativa strains that naturally grow six-feet tall.

Mixed-height grow ops can be a problem — unless, that is, all your plants are same-age clones from the same mother. If you grow one strain from seed, you might get phenotypes with height differences, especially due to variations in the length of bloom-phase stretch. And even if you grow multiple strains from seed from the same cannabis category (i.e., sativa, indica, Afghanica), you can still end up with plants of differing height. If this results in plants that are four-feet tall and others that are five feet, you have to adjust your grow-op lighting accordingly so that the plant canopy is a uniform distance from your grow lights.

I had a mixed grow in which some plants were close to six-feet tall and others topped out a little more than four feet after their bloom-phase stretch was complete. I have multiple grow lights on adjustable-length light leashes, which allowed me to raise some lights to keep leaf surface temperature from creating plant burn on the tallest plants, and lowered other lights to ensure maximum light-to-canopy distance for the shorter plants.

In circumstances when it isn’t possible to adjust the height of grow lights enough to prevent plant burn, I might move the taller plants to the outer perimeter of the grow-light footprint so those plants aren’t directly under the bulb or LED chips.

For shorter plants in situations where I can’t adjust light height enough to accommodate them, I place sturdy boards on concrete blocks underneath the plant pots to raise them off the floor and get their height even with their taller neighbors. Some growers call this a stadium grow. I also bend, tie and train to lower taller plants to a height more in line with shorter plants.

cannabis strains

In this outdoor grow op in Northern California, the grower is cultivating Girl Scout Cookies on the left, and Strawberry Kush on the right.

The Benefits Of Running A Mixed-Strain Grow Op

Admittedly, it does create more work to run a grow op with a wide variety of plant genetics. So why do it at all?

Well, I provide cannabis to several people and each of them has different strain preferences. I must grow what they like, and they all like something different. It’s important to keep customers happy, so I grow what they want to consume, even if it creates extra work in my grow op. My marijuana motto is, “Variety is the spice of the high.” I stock a bud and concentrates inventory from many kinds of cannabis, and I like to mix and match them to create different experiences and effects.

One day, I may want a CBD variety to help mend a sports injury. The next day, I may want a powerful indica to help aid sleep. The day after that, I may want to vape sativa so I can write music. Only a mixed grow room allows me to produce this versatile lineup of fresh buds. As a cannabis aficionado, a mixed grow up gives me more types of buds, scents and photographic opportunities than a single-strain grow. It’s an olfactory delight to walk through the grow op and smell skunk here, lemon there, diesel over here, and a fruity bud all in the same room.

Ditto for photo opportunities.

Perhaps the biggest pro when it comes to cannabis strain diversity is that surprisingly, it helps reduce the workload crunch at harvest time. I’m a solo grower and retailer. When I have a single strain crop and every plant’s ready for harvest at once, it’s an exhausting marathon of cutting and trimming, followed by another marathon of sorting, trimming and packaging after drying and curing.

When I have multiple strains in the same room, some finish earlier than others, enabling me to do a rolling harvest that’s easier than an all-at-once gargantuan intake.

Growing numerous strains at the same time also allows me to conduct a breeding project that requires different varieties and some male plants to be grown together. This usually involves strains with different genotype and phenotype characteristics, so there’s no way to avoid a mixed grow room with variant growth rate, bloom-phase duration, height, resilience and nutrient needs. Yes, it adds the extra hassle of having to spot males and remove them to a separate grow room or grow tent until I can collect their pollen and chop them. But the benefits I get from growing a mixed-strain garden far outweigh the extra work and challenges.

On the other hand, I know growers who cultivate one strain from clone year-round because it’s the simplest and most reliable way to grow, assuming their mother plants are uniform and healthy. Additionally, other growers who want different types of buds break their year into three or four seasons, growing one strain per season. They end up with several different strains to sell and consume, but they avoided the hardships of growing different strains concurrently.

A variant of that tactic is to synchronistically grow different strains from the one cannabis category. I’ve run Kush, indica, sativa and Afghanica strains together, but because the strains were all from the same cannabis family, they had relatively similar height, bloom-phase duration, structural characteristics, and feed requirements. There was still extra work compared to a garden consisting of only one strain grown from uniform clones, but it wasn’t that much of a big deal.

Only you can decide how many cannabis strains you can ably grow together for each grow season. I require variety and continue to grow from seed, not just clone. I grow several seed strains in two of my four grow ops per year, and a uniform clone crop in the other two seasons. I hope variety soon becomes the spice of your cannabis grow rooms, too.

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