You have a lot of choices to make when you’re planning your growing marijuana seasons, and one of the most basic is whether you’ll grow one marijuana strain or multiple strains at the same time.
Part of the facts and context that shape your decision relates to whether you grow from seeds, clones, feminized seeds or non-feminized seeds. It also depends on your growing marijuana goals. If you’re running commercial marijuana gardens, you want plants uniform in phenotype, physical structure, nutrients needs, gender, growth characteristics, height, and bloom phase length. Growing only one marijuana strain at a time from clones promotes efficiency and saves labor in the following ways:
*You can count on cloned plants from the same motherplant to grow the same way at the same rate and reach the same height with the same structure.
*They’ll all need the same feed program.
*They’ll all be female, and they’ll all have the same resistance to pests and diseases.
*They can all be harvested at the same time.
This shows the ease of phenotype-guaranteed clones, such as those provided by professional clone factories like California’s Dark Heart Nursery. Even the most well-bred, stable marijuana seed crop shows phenotype variability. If you’re growing from high-quality feminized seeds of one strain, you’ll often see two or more phenotypes. If you’re growing from high-quality non-feminized seeds, you might see two or more phenotypes, and about half your plants will be male.
Here’s the range of variability in crop development and outcomes you can expect from a grow room:
- At the lowest end of the variability range is growing quality clones from one motherplant. Much more variability comes when growing one strain from feminized seeds.
- You get more variability if you’re growing non-feminized seeds of one strain.
- You get a lot of variability when you grow clones from several different motherplants 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 do in your marijuana grow op.
Here are the the extra challenges you’ll deal with if you grow multiple strains instead of just one strain:
- Grow phase length for different strains will vary.
- The need for and timing of topping and other training for grow phase plants will vary widely.
- Grow and bloom phase hydroponics feeding parts per million vary depending on strain.
- The ideal time for starting bloom phase will vary widely depending on strain.
- Development of early budding sites and the maturation flow for buds will be very 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, and others not.
- Flushing and harvest timing for each strain will be different.
Making Logistical Changes to Maximize Multi-Strain Grow Ops
As you can easily see, a multi-strain garden requires extra work and skills. When I run grow ops with several different strains, I have to mix different feed programs for each strain and administer nutrients separately to groups of plants. During bloom phase, for example, I use several cannabis-specific supplements Bud Ignitor, Big Bud, Bud Candy and Overdrive that have ingredients to make the earliest and most potent buds as bloom phase floral structures ripen over time. In a single strain garden, I can easily do my feed program because every plant is getting the same food. In multi-strain gardens, strains will mature at different rates, making necessary more than one feed program. These things add an hour or more to my daily growing marijuana labor time.
I’ve also noticed that in an outdoor garden where some strains had natural terpenoid defenses so they weren’t attacked by spider mites, thrips, aphids and other pests, plants from other strains were magnets for pests. If you’re going to plant one strain or many, try to plant strains known to resist pests and diseases that frequently occur where you grow.
I use systemic and foliar spray inputs to deter and control pests, so the differential between pest-resistant plants and pest magnet plants meant different feed programs and different foliar sprays. In outdoor marijuana growing, I have to take into account wind direction, because I didn’t want the pest-deterrent foliar sprays to blow over onto the buds of my pest-resistant plants.
Short & Tall Cannabis Plants in the Same Garden
One of the most impactful differences in a multi-strain, multi-phenotype garden is in plant structure and height. Some growers have told me I’m dumb for growing short, squat, single-cola Afghanica in the same grow op as long, tall, thin-bud Sativa strains.
Although there are sometimes good reasons to grow multiple strains in the same garden and I’ll tell them to you later on in this article, I too felt dumb sometimes when I saw how much logistical trouble I caused myself by having Indica strains that naturally grow four feet high in the same room with Sativa strains that naturally grow six feet high.
Mixed height grow ops can be a problem unless all your plants are same-age clones from the same mother. If you grow one strain from seed, you might get phenotypes with different height, especially due to variations in the length of bloom phase stretch. If you grow multiple strains from seed, even if they’re all from the same cannabis category (Sativa, Indica, Afghanica), you can still end up with plants of different height.
If you have plants that are four feet tall and others that are five feet tall, you have to adjust your grow op lighting height and/or your plant height so the plant canopy is a uniform distance from your grow lights.
For example, 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 finished. Because I have multiple grow lights on adjustable-length light leashes, I raised 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.
When it isn’t possible to adjust the height of grow lights enough to maximize light delivery while preventing plant burn, I might move the taller plants to the outer perimeter of the grow light’s footprint, so they aren’t directly under the grow bulb or LED chips.
For shorter plants in situations when I can’t adjust light height enough, I adjust plant height by putting sturdy boards on concrete blocks to raise the plants off the floor and get them even with their taller colleagues. Some growers call this a “stadium grow.”
I also using bending, tying, and training to lower taller plants to a height more in line with shorter plants.
Benefits of Running a Mixed Marijuana Grow Op
You see it creates more work for you to run an indoor grow op or outdoor garden using a wide variety of genetics so you have plants with different growth rates, heights, pest and disease resistance, maturation rates, feeding requirements and harvest timing. So why do it at all? One reason is I sell marijuana to several people and each of them has strain preferences. I must grow what they like, but they all like something different. It’s important to keep these people happy, so I plant what they want to inhale, even if it creates extra work.
Even if I wasn’t providing cannabis to other people, 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 might want a CBD variety to help with a sports injury. The next day I want a powerful Indica to help me get to sleep. The day after that I want to vape Sativa so I can write and perform music. A mixed grow room allows me to produce this versatile line-up of fresh buds.
As a cannabis photographer and 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. The same lovely diversity helps me as a cannabis photographer.
Marijuana strain diversity reduces the workload crunch at harvest time because the plants aren’t all ready for harvest at the same time. When I have a single marijuana strain crop and every plant’s ready for harvest at the same time, it exhausting marathon cutting and trimming sessions, followed by another marathon doing final sorting, trims 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 harvest.
Another reason I grow different strains at the same time is so I can do a breeding project. Breeding requires different strains and some male plants to be growing at the same time. It adds the extra hassle of having to spot male plants and remove them to a quarantined grow room or grow tent all their own until I can collect their pollen and chop them.
A breeding project usually involves strains with different genotype and phenotype characteristics, so there’s no way to avoid a mixed grow room that has plants with variant growth rate, bloom phase duration, height, resilience, and nutrients needs.
The benefits I get from growing a mixed-strain marijuana garden outweigh the extra work and logistical challenges that come from it. On the other hand, I know growers who grow one strain from clone year-round because it’s the simplest and most reliable way to grow, assuming the motherplants are uniform and healthy.
Other growers who want different types of buds break their year into 3-4 seasons, growing a different cannabis strain each season. They end up with several different strains to sell and use, but they avoided the hardships of growing different strains at the same time.
A variant of that tactic is to grow different strains from the same cannabis category at the same time. I’ve run Kush, Indica, Sativa, and Afghanica cannabis gardens that had several strains growing at the same time, but because the strains were all from the same cannabis family, they had relatively similar height, bloom phase duration, structural characteristics, and feed program 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 marijuana strains you grow season. I need marijuana strain variety, and am growing marijuana from seed, not just clone. I grow several marijuana seeds strains in two of my four grow ops per year, and a one-strain clone crop in the other two seasons. I hope variety is the spice of your cannabis grow rooms too!