Kevin Jodrey at the Wonderland Nursery Garden CenterKevin Jodrey at the Wonderland Nursery Garden Center
Kevin Jodrey at the Wonderland Nursery Garden Center

There is one key concept to understanding supplemental lightning with cannabis: cannabis goes into flowering based on hours of consecutive darkness, not hours of consecutive light. The consecutive darkness allows certain hormones to build up to a critical level, which than causes changes in the plant. Light prevents this process from occurring.

“Why are we fracking oil to grow a plant in a warehouse, when we can just put it out in the sun?”

In a garden center, nature can take its course. The natural length of the days will impact a plant just as if it were exposed to the elements. The garden center provides a more controlled environment, keeps out animals, protects against the elements, and allows for temperature stability. For these reasons and more, greenhouses and hot houses have been in use for centuries.

With the advent of modern lightning technology, supplemental lighting has become possible. Lights of a certain sort are placed at certain locations, and hung from the metal frame. The placing of these lights is based on horticultural science principles, and manufacturer’s guidelines about the area of coverage. The purpose of these lights also impacts placement.

At Wonderland Nursery’s garden center, we place our lights to prevent flowering. This requires only minimal amounts of light and electricity. We have two variations we employ: a summer and a winter variation.


Summer Variation

The summer variation has four (4) units hung that are referred to as “46s.” They use T-5 light bulbs, that are four (4) feet long. There are six (6) of them per unit. Thus, we have “4 x 46” or “Four Forty-Sixes.” T-5s are a standard fluorescent plant light, also used in display cases like in jewelry stores. T-8s are a standard office fluorescent light. T-12s are a standard “shop light” seen in workshops, hardware stores, etc. The number indicates the diameter. T-5s are 5/8ths of an inch. T-8s are 8/8ths, 1 inch. T-12s are 12/8ths, or 1.5 inches.

Each of these T-5 bulbs uses 54 watts. Combined, the four (4) fixtures use 1.2 kilowatts per hour when in operation. The fixtures are only in operation during nighttime hours. These lights are on a timer. By engaging in this activity, we can ensure that the cannabis plants in the garden center do not enter into flowering. The garden center is then able to function during the summer as a holding space for mother plants. The sun does all the “heavy lifting” for plant growth. This consumes about 12 kwHs (kilowatt hours) of electricity per day.

Winter Variation

The winter variation has six (6) 1000w fixtures, which provides a fixture for every 100sq/ft of canopy space. These operate the same as the T5s, but are intentionally more powerful. Less sunlight in the winter means supplemental light is needed to aid plant growth. Combined, these fixtures use 6 kwHs per hour, leading to 72 kwHs of electricity per day.

Yearly Electricity Total (Garden Center)

Over the course of 6 months, the summer variation consumes approximately 2200 kwHs. Over the course of 6 months, the winter variation consumes approximately 13,200 kwHs. Combined, consumption is approximately 15,500 kwHs.


To replicate the same activity in an indoor environment within the same footprint (600 sq/ft of canopy space), would require twenty-four (24) 1000w fixtures. These fixtures would need to be in operation 18 hours per day. Further, support equipment is necessary to sustain the indoor environment, raising the number to approximately 456 kwHs per day.

The above numbers do not take into account that, to produce similar outcomes as the greenhouse, even more space would be needed. The sun provides superior quality light, which increases yields and quality of clones. In reality there is not a 1:1 ratio to be found here. Our experience indicates a 2:1 ratio, at a minimum, is needed.

Yearly Electricity Total (Indoor)

Over the course of a year, the indoor method uses approximately 167,000 kwHs for a same sized space, and approximately 334,000 kwHs to produce a similar outcome as supplemental lightning.


Indoor cultivation for mom & clone cultivation consumes 1000% to 2000% more electricity than garden center cultivation.

Wonderland Nursery’s garden center production, over the course of a year, consumes approximately 15,500 kwHs. v A similar square-foot indoor garden consumes approximately 167,000 kwHs. To produce a similar output consumes approximately 334,000 kwHs.

A common joke in the cannabis industry is, “Why are we fracking oil to grow a plant in a warehouse, when we can just put it out in the sun?”

Using a garden center reduces electricity usage dramatically. Garden center cultivation requires between 1/10th and 1/20th the amount of electricity of indoor mom & clone cultivation. Inversely, indoor cultivation for this purpose consumes 1000% to 2000% more electricity than garden center cultivation.

Supplemental lighting is a standard practice in the horticultural and agricultural world. It is considered the most environmentally friendly method of proceeding. In places like the Willamette Valley, a plant nursery would cover several acres with large greenhouses so that all activities could occur in a supplemental light environment, eliminating almost entirely the need for the massive electricity waste of indoor production.

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