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INSIGHTS BLOG > Cannabis Cultivation: Indoor vs. Outdoor vs. Greenhouse


Cannabis Cultivation: Indoor vs. Outdoor vs. Greenhouse

Written on 22 September 2020

Ruth Fisher, PhD. by Ruth Fisher, PhD

There are three basic locales for growing cannabis: indoors, outdoors, or in greenhouses. Greenhouses enable growers to benefit from natural light, while also being able to strategically block out light to induce quicker flowering. Budget-friendly greenhouse operations are more subject natural climate variations, while higher-end greenhouses are more similar to indoor grow operations that benefit from natural lighting.

Which of the three locations is best?

As with most interesting topics, each locale has associated advantages and disadvantages. I collected information on the advantages and disadvantages of the different grow locales and organized them into three general groupings: comparisons of grow environment issues, comparisons of flower quality issues, and comparisons of cost and effort issues. This analysis presents these comparisons.

Grow Environment

Of course, the biggest difference in the grow environment between the three locales is the amount of control over the grow environment that cultivators have under the three different regimes. Indoor grows are fully-controlled by growers, while outdoor grows are fully subject to the whims of Mother Nature.

One of the most important issues I’ve found regarding quality of yield is lighting. There seems to be a consensus that natural lighting is superior and that artificial lighting simply cannot replicate the benefits of natural sunlight.

On the other hand, control over artificial lighting enables growers to encourage plants to flower sooner than they otherwise would. The ability to induce flowering enables growers to achieve greater turnaround, that is, more harvests each year than outdoor farming allows

Another big issue concerning the grow environment is pests. It’s not clear which environment is better for pest control. Outdoor grows benefit from natural predators that can control pest populations, yet outdoor grows generally still require pest management. Indoor growers may have to use pesticides, yet, on the other hand, indoor growers may be able to achieve pest-free environments.

A summary of the advantages and disadvantages of the different grow environments is presented in Figure 1A (sources are provided in Figure 1C).

Figure 1A

1 ivo grow environ

Quality of Flower

There is consensus that indoor grows generate flower with greater “bag appeal,” that is, greater aesthetics, since outdoor flower is often damaged when exposed to the elements. Furthermore, flower grown indoors tends to generate denser buds that are more densely covered in trichomes, filled with higher potency THC. Yet, while outdoor buds are “bigger and chunkier,” natural sunlight produces greater overall production (volume) of resin and perhaps depth of experience.

Indoor flower tends to be brighter in color, while outdoor flower is deeper and darker. Finally, indoor cultivation provides an environment that’s more amenable to standardization and consistency in output, as well as cultivation of a broader range of specialty varieties.

A summary of the advantages and disadvantages of the different aspects of flower quality is presented in Figure 1B (sources are provided in Figure 1C).

Figure 1B

2 ivo qual

Cost/Effort

Finally, there is also consensus that outdoor cultivation is much less expensive than indoor cultivation, requires less fussing and tweaking of care, and is much less resource (power and water) intensive. A summary of the advantages and disadvantages of the different aspects of cost and effort are presented in Figure 1C.

Figure 1C

3 ivo cost

Summary

To summarize, growing cannabis indoors tends to involve:

  • Greater environmental control and faster turnaround times, and
  • Greater bag appeal, variety, and consistency of output, but
  • Greater costs and effort and more intensive use of resources

While growing cannabis outdoors tends to involve:

  • Natural sunlight yielding greater overall resin production, perhaps with a greater depth of effects, requiring
  • Lower costs and less fuss, but generating
  • Less consistent output with fewer cultivar varieties.

It seems, then, that indoor growing is perhaps best suited for higher-priced cannabis desired for aesthetic appeal, specialty profiles of compounds or consistent quality of output, while outdoor growing is best suited for lower-priced, more mainstream production.