I interviewed a master grower how to grow the best marijuana. He worked at a combination adult use and medical retail business in downtown Denver.

I asked him to discuss the factors to consider to grow the best marijuana. The following is his awesome response.

Grower: “The grower should strive to create the optimal environment and then stay out of the way.”

“In general you want to keep air flowing, don’t give the plants too much water, and don’t let it get too cold when the lights turn off.”

Air Temperature

70 – 78⁰ when the lights are on with a 15⁰ drop when the lights turn off. Also the temperature drop can spike humidity so you want to be aware of that.

Humidity

“Too much humidity causes mold. 30% humidity is optimal. If the humidity is low growth will slow down.”

Air Circulation

“Lights create heat. Most growers have moved to vented lights. The goal is to move the air through the room and through the lights themselves. You also want lights that don’t put out excess heat so you can get the lights close to the plants without creating excess heat. You want a fresh air intake in the room and then you want to move the air. Blowing air on the plants makes them stronger, though I am not suggesting anything extreme when I say this.”

CO2

“I don’t’ add CO2 to the air, nor do I knock it. I get good results without it. My impression is that CO2 can make the buds look bigger but not weigh as much.”

Medium

“There are mediums made just for growing marijuana. These are usually made from Coco fiber. One popular product is Fox Form Ocean Forest Soil, but I prefer Royal Gold Coco Fiber.”

pH

“I start out with a pH of 5.8 when the plants are young. This allows them to uptake Nitrogen better during the vegetative stage, about 3 – 5 weeks. I use chemical to lower the pH of the water. Then during the flower stage I increase pH to 6.5 to uptake Phosphorous better, about 9 weeks.

Lamps

“I prefer 1000 W bulbs with 6 – 12 plants per bulb. A good grower should be able to harvest about 1 1/2 – 2 lbs. of pot per 1000 W light in about 63 days. Lower yields are a reflection of conditions in the environment.”

Nutrients

“I use a product by House and Garden, out of Holland, which is strictly for growing cannabis, but I use about 25% of their recommended dosage. I believe that ‘less is more’ when it comes to food.”

Water

“One of the issues with water is what’s in it to start with. Denver water has a total dissolved solids (tds) content of about 150 parts per million (ppm). Water is nearby mountain communities can have a higher tds. Reverse Osmosis is a pain to use but you have to do it if the tds gets over 300 ppm.

“I don’t use drip systems. Instead I water by hand. This way I give the plants the precise amount of water they need without overwatering the plants that are growing more slowly.”

“In either can you want to remove chlorine or chloramine which inhibits growth and fluoride which inhibits phosphorous uptake during flowering.”

“The Bud Booster allows the grower to remove the bad things in water without the hassles of RO. Jim is like the water doctor for growers.”

Life Cycle

The life cycle he discusses above includes 1 – 2 weeks for a cutting to root, 3 – 5 weeks of vegetative growth, then 9 weeks of flowering.

Editor’s note: You can vary the time of harvest to obtain different effects. I personally like to grow for a combination of high potency and great taste. Learn more here.

He concludes by saying “Finally, I would add that the grower should solve problems, don’t create problems by making growing too complex. The plants these days are great healthy strains. Provide the right environment and they’ll grow quickly and produce well.”