Lighting, Pesticides & the Future of Cannabis Cultivation: Q&A With Rx Green Solutions’ Head Grower

, Lighting, Pesticides & the Future of Cannabis Cultivation: Q&A With Rx Green Solutions’ Head Grower

By Becky Olson

Jonathan Nielson is a Colorado native with nearly a decade of cultivation experience in the legal marijuana industry.

Now, he’s the master grower for Rx Green Solutions’ cannabis research and development facility in Denver, where he leads a team focused on the science of nutrients used in marijuana cultivation.

Rx Green Solutions grows cannabis specifically for a Denver medical and recreational cannabis shop. Before moving its cannabis to the store, the company conducts scientific trials designed to pinpoint an ideal nutrient mix and regimen in a bid to figure out how to increase yields and improve flower quality and safety.

Nielson sat down with Marijuana Business Daily in September to talk about his research, scaling a marijuana grow and the future of cannabis cultivation.

One of the hot topics in cultivation right now is how various lighting technologies can improve quality and yields while also reducing energy requirements. What lighting technology does Rx use and why?

We use double-ended lighting technology because it gives you a larger square footage of light for the same amount of power. The bulbs ignite from both sides, as opposed to single-ended lighting that you screw in on one side.

The industry has discovered different spectrums will do different things for the plant, so what this allows us to do is put different bulbs in there for different light spectrums.

Use of pesticides is another contentious topic in the industry today – what’s your perspective on pest management?

The key to pest management is to be proactive. We find that if you have to react to a pest problem – whether it’s fungus, powdery mildew, etc. –you’re on the back side of a very difficult situation to manage. You’ve got to get ahead of it by anticipating the worst, but hoping for the best.

All of the pesticides we use fall under the 25b class (minimal risk) of federally exempt substances. We use an integrated pest management system where we spray twice a week with different types of ingredients.

You have to rotate your regimes, put them in combination, make cocktails. If you use the same thing all the time, pests develop resistance. But when you use an integrated system, it significantly lessens the chance of that happening.

What are some of the top challenges for today’s commercial marijuana cultivators?

One of the things we’re very conscious of is the word “simplistic.” It’s one thing for a home cultivator or small cultivator to manage multiple (nutrient) products, but with large-scale operations, you have to keep it simple.

You have a lot of people coming in and out of those facilities, and they bring (pathogens) with them – how do you keep a sanitary environment?

Another challenge is maintaining efficiency. The prices keep going down, but the costs of production stay the same. Simplicity is key.

What advice do you have for cultivators who are scaling up from smaller cultivation sites to large/commercial ones?

You want to take small steps. You don’t want to change a bunch of things all at once or you won’t know what worked and what didn’t work.

Do slow trials, test things out – you’ve got to be looking ahead at what’s coming in the industry too.

Speaking of the future of the industry, what are some of the things you are preparing for and what trends do you predict will play out?

I do think that LED lighting in the next few years is really going to start getting up and going. Irrigation is also something that is almost new to the cannabis industry in a certain way.  I think you’re going to see more companies adopting use of dosatrons (automatic fertilizing technology) in the near future.

I hope to see more regulations come down the pipe, especially with regard to consumer safety. There’s all kinds of regulations for growing food, tobacco – we barely have any in the cannabis industry.

Becky Olson can be reach at [email protected]

6 comments on “Lighting, Pesticides & the Future of Cannabis Cultivation: Q&A With Rx Green Solutions’ Head Grower
  1. Grady Padgett on

    Well golly-gee Jonathan were you quoting from a chat you had with some 3rd Graders? Surely you don’t talk this way to other professional growers?

    Come-on man if you want to impress your peers you need to get a little more, no, a heck of a lot more detailed when asked questions…we can handle it!

    For example: when using a proactive IPM approach give us some details on what chemicals you use, how and when you use them, or is this some kind of secret? Did I read you saying you mix different pesticides? Yikes!

    Using only one at a time I rotate through 4 different “…cides”: Safers, Trilogy, Neem oil, and Stylets Oil. Each is mixed at 2 tablespoons per gallon; mixing water is between 65 and 75 degrees f.; sprayings are always “first thing” in the morning before sunlight closes the leaves stoma!…or at “first light” for all you indoor growers. My crew use a battery powered (!) back-pack sprayer set to low pressure; starting at the lower leaves spraying up-wards onto all leaf undersides…and even the ground around the plant out to it’s “drip line”, then starting at the top and spraying down-wards on each leaf’s top surface…get them to dripping!

    Plants don’t know about weekdays/weekends; these IPM sprayings are every 3 days continually from rooted clones through end of each veg cycle…never during bloom cycle.

    Lot of work this is, yes, but I have no pest problem, have had none over my last 5 years and in the same greenhouse complex, too.

    Each harvest has selected samples sent to my favorite testing lab in Santa Cruz, CA, and is posted, too.

    If you’ve only been doing this “legally” for 10 years I can understand why you’re a little lite on details.

    I’ve only been at it for about 45 years now, and I’m still learning, too; every harvest has its own uniqueness, that’s why I also keep a daily laboratory journal log to help my old brain remember…reference back to this or that.

    No, man, I’m not putting you down either; it’s obvious from what you’ve said you’ve a lot more you could say if given time/space enough! Hope to run into you at one of the conventions, then we can get down to nuts & bolts, share, teach, and learn form & with each other.

    Best of everything, guy. Happy Holidays for you and yours, and, when you get tired of Colorado and want to see some Cali Wow! give me a shout.


  2. pw on

    “I hope to see more regulations come down the pipe”

    No, my friend. This plant exists to free humanity, not further enslave.
    We need less government intervention, not more…in EVERYTHING.

  3. gloria on

    What a shame! Pesticide cocktails? I hope all the people that get their MJ from these people are actually reading this, & stop buying product that has pesticides used on it. Mixed together or otherwise, pesticides should be banned permanently for any MJ production, period! It can be done right, with no pesticides whatsoever! Come on people! Sure, it’s time consuming, but fairly simple to do right! If you need to use pesticides you should not be in this industry!

    • Doc Deadhead on

      Agreed, if you do things right there will be no catch up to the bug problem. I use organibliss(natural plant based organic) 3 times a week in veg and up to obvious transition(about 10 days indoors).

      If any bugs show up after that there isn’t enough time to cause an infestation, at most is a branch you have to throw away.(yea, throw away, bug shit is not for consumption!).

      We look at every leaf on every plant once a week for issues. Yes, it takes time but you are able to deal with all situations BEFORE they become problems. Oh yea, no pesticides either.

    • Justin Thomas on

      Gloria, if you know anything about Colorado regulations, now enforced by the Department of Agriculture, you would know that these, “pesticides mixed”, are some of the softest products with themost harmless modes of action that are effective. Much more strict about the products used on cannabis then many food crops…

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