Growing multiple cannabis strains in a commercial setting sounds like a good idea. The more the better, right? Not exactly. Managing several dozen varieties – or cultivars – on a commercial scale can be extremely difficult. Even with ornamental and edible greenhouse crops, it’s unlikely to find a grower growing 30 varieties of poinsettia or dozens of different hydroponic tomatoes on the vine.

Instead, most growers focus on a few top performers that impress customers and lend themselves well to commercial-scale production. New cannabis operators looking to succeed in the industry would do well to emulate this philosophy.

Offering lots of variety at a retail dispensary is great, but growing loads of different cultivars at one facility can get tricky. Here’s why:

Stellar cultivars are compromised

Loading a bloom room or greenhouse bay with multiple cultivars can hamper a grower’s ability to adapt to individual preferences. Optimal light, EC and humidity levels can vary from week to week for different cultivars, so growers may be forced to find a balance that will not maximize each variety’s potential.

Harvesting is less efficient

Perpetual harvest programs rely on a specific calendar. Often, growers have less than 24 hours to empty and sanitize a grow room before restocking it with new plants. Choosing the perfect time to harvest can be difficult with many cultivars in the same room. Inevitably, plants are harvested too early or too late, or if the grower chooses to harvest when each cultivar is ready, they end up with grow rooms that are not at full capacity.

Automation is difficult

Automation is less feasible when there are many different cultivars in one room. Automation depends on performing the same activity in the same way for all plants in a growing area. With more variety, there are more differences in irrigation volume and frequency, fertilizer strength, and transplanting times. Even non-automated tasks, such as pinching, trimming, and leaf stripping, may need to be done multiple times in the same room to accommodate the right time for each cultivar.

Headache for start-ups

New breeding companies are particularly susceptible to the dilemma of too many genetics. Launching a start-up in a new facility with new growers is hard enough, and adding too many new cultivars is just asking for trouble. It’s common for new businesses to over-complicate their launch with too many varieties.

Increased risk of spreading pathogens

Cultivars that are not in full production but are kept “just in case” can put the rest of the facility at risk. Mother plants that aren’t propagated frequently don’t usually get the attention they deserve. They are often piled up in the back of Mom’s room or in the corner of a greenhouse. Neglected plants are more susceptible to insect and disease infestation, and once these pathogens find a home, old or unused mother plants can serve as an epicenter for the spread of pathogens through a facility.

So how much is too much? There is no universally correct answer, but 10 cultivars is a great place to start. If you think your team may have gone too far with too many varieties, consider these tips to help simplify your cultivar selection:

1. Give people what they want

Start by making sure you’re growing cultivars with traits that appeal to most cannabis users. This generally falls into four broad categories:

• High THC
• Low THC content
• High CBD, no THC
• 1:1 ratio CBD to THC

Once you’ve covered them, add more cultivars with traits that are likely to be in continued demand, especially high-THC varieties. Beyond the main cannabinoids, ensure that all strains offer consumers a unique and rich blend of terpenes.

2. Limit the number of cultivars per room

Growing a single cultivar per room would be ideal, but this is not always feasible. At least try to organize grow rooms with cultivars that finish flowering within a few days of each other. Once a cultivar is determined to be ready for harvest, there is a window of approximately five days before it is in danger of becoming overripe. Grouping eight and nine week old varieties together in the same room might seem like a good idea, but harvesting at the start of eight weeks (50 days) or the end of nine weeks (63 days) can mean a world of difference.

3. Organize by growth habit

Group cultivars with similar growth characteristics together. Growing short, sturdy plants will be more successful if they are not mixed with tall, tall varieties. The more uniform the room, the easier it will be to automate and schedule work activities.

4. Maintain non-production cultivars in a tissue culture laboratory

If a cultivar is not actively propagated but is still considered a “keeper”, let someone else keep it. Preferably a tissue culture laboratory. These companies have sophisticated methods of storing genetics that require almost no space at all, such as encapsulating synthetic seeds. This technology encapsulates the tissues used for plant propagation and holds them in a protective coating.

If your cultivation program is struggling to stay above water, review the varieties in production. If there are more than ten, it’s probably time to cut back and focus on consistent winners.

Want more tips for growing cannabis successfully? Join me on June 14, 2022 at 11:00 a.m. EST as I share business tips for starting a new cannabis growing business during an online workshop, “Recipe for Success: 11 Ingredients for an excellent cannabis cultivation start-up”.

In this 90-minute interactive webinar, I’ll share ideas on buying versus building your production facility, tips for selecting genetics, and tips for establishing a lean grow team. I will also show auditors how to calculate yield estimates and determine lead times for new production sites.

Click on here to register.