Growing Cannabis in Oklahoma

Growing cannabis in Oklahoma has evolved considerably in recent years, especially after the state legalized medical marijuana in 2018. The unique climate and conditions of Oklahoma present specific challenges and opportunities for cannabis cultivators. This article provides an in-depth overview of the nuances of cannabis cultivation in Oklahoma, from the legal framework to the practical aspects of growing in this region.

Legal Framework for Cannabis Cultivation in Oklahoma

In June 2018, Oklahoma voters approved State Question 788, legalizing the medical use of cannabis. This measure does not list specific qualifying conditions, allowing physicians to prescribe medical cannabis for any patient they believe might benefit.

Licenses and Regulations

  • Anyone over 18 with an Oklahoma residence and a valid physician’s recommendation can apply for a medical marijuana patient license.
  • Commercial growers in Oklahoma need to obtain a commercial license, renewed annually.
  • Unlike many other states, there is no cap on the number of commercial grow licenses, leading to a rapid increase in the number of cultivation sites since legalization.
  • Growers must ensure their products are tested for contaminants like pesticides and molds and meet state-established potency standards.

Climatic Conditions for Cannabis in Oklahoma

Oklahoma features a temperate climate, but it can also experience extreme weather conditions that may influence cannabis cultivation.

Temperature and Light

  • Summer temperatures can soar above 90°F, which can cause heat stress to cannabis plants if not monitored.
  • The natural light cycle in Oklahoma is conducive to outdoor cultivation, particularly during the vegetative stage in late spring and early summer.

Water and Humidity

  • Oklahoma can be prone to both droughts and floods. Thus, consistent irrigation and good drainage systems are crucial.
  • Humidity, particularly during the late summer, can be high, increasing the risk of mold and mildew.

Soil Quality

  • The state’s soil is varied, with sandy, loamy, and clayey soils. For cannabis, well-draining loamy soil is ideal. Adjustments might be needed depending on the specific region within Oklahoma.

Indoor vs. Outdoor Cultivation

Given Oklahoma’s climate, both indoor and outdoor cultivation have their merits.

Indoor Cultivation

  • Offers a controlled environment, essential for specific strains or high-quality yields.
  • Allows for multiple harvests in a year.
  • Requires significant investment in equipment like lights, fans, and humidity control systems.

Outdoor Cultivation

  • Capitalizes on Oklahoma’s natural light cycle and can produce substantial yields.
  • Lower startup costs compared to indoor growing.
  • Exposed to the unpredictability of Oklahoma’s weather, hence requires more diligent monitoring.

Pest and Disease Management

Due to its central location, Oklahoma cannabis cultivators must be vigilant against a range of pests and diseases.

Common Pests

  • Spider mites, aphids, and whiteflies are prevalent. Regular inspections and organic insecticides can help manage these pests.
  • Caterpillars can be particularly damaging. Hand removal and introducing natural predators like ladybugs can be effective.


  • Given the high humidity, powdery mildew and botrytis (bud rot) are primary concerns. Proper spacing, airflow, and organic fungicides can mitigate risks.
  • Regular soil tests can help detect and prevent soil-borne diseases.

Harvesting and Processing in Oklahoma

Timing the harvest is crucial for optimal potency and yields.

Harvest Indicators

  • Trichomes, tiny resin glands on the buds, change in appearance as they mature. When half of these trichomes turn milky white with some turning amber, it’s usually time to harvest.
  • Pistils, the hair-like structures on the buds, will darken and curl in.

Drying and Curing

  • After harvest, buds are typically hung upside down in a controlled environment (50% humidity and around 70°F) for about a week.
  • The dried buds are then placed in jars for curing. This process can take several weeks but is vital for flavor development and potency preservation.


Growing cannabis in Oklahoma comes with its unique set of challenges and opportunities. While the state’s regulatory framework is one of the most liberal, cultivators must navigate the climatic variability and pest concerns skillfully. By understanding the nuances of the region and investing in preventative measures, Oklahoma’s growers can yield high-quality cannabis that serves the state’s burgeoning medical marijuana community.