How to grow weed in a greenhouse

on November 13, 2023

Cultivating cannabis in a greenhouse offers a controlled environment that can significantly enhance plant growth and yield. Whether you're a seasoned cultivator or a beginner with a green thumb, this guide will take you through the essential steps to successfully grow weed in a greenhouse.

Choosing the Right Greenhouse

Before diving into the cultivation process, it's crucial to select the right greenhouse for your cannabis plants. Consider factors such as size, ventilation, insulation, and light transmission. A well-designed greenhouse provides a stable environment for your plants, protecting them from external elements while allowing you to regulate crucial factors like temperature and humidity.

Optimal Environmental Conditions

Maintaining the ideal environmental conditions is key to a successful cannabis harvest. Here's a breakdown of the factors you need to monitor and control:

  1. Temperature: Cannabis plants thrive in temperatures between 70-85°F (21-29°C) during the day and 58-70°F (14-21°C) at night. Invest in a reliable heating and cooling system to ensure a consistent temperature inside the greenhouse.

  2. Humidity: Keep humidity levels between 40-60% during the vegetative stage and lower it to 40% or less during flowering. Proper ventilation and dehumidifiers can help achieve and maintain these levels.

  3. Lighting: While greenhouses utilize natural sunlight, supplementing with artificial light during cloudy days or winter months can boost plant growth. High-quality LED or HID lights are suitable options.

  4. Ventilation: Adequate airflow is crucial to prevent mold and ensure optimal CO2 levels. Install exhaust fans and louvers to create a well-ventilated environment.

Selecting the Right Cannabis Strain

The choice of cannabis strain plays a significant role in your greenhouse cultivation success. Consider factors such as the plant's size, growth characteristics, and flowering time. Indica-dominant strains are generally more compact and suitable for smaller greenhouses, while sativa-dominant strains may require more vertical space.

Soil and Nutrients

Selecting the right soil and providing appropriate nutrients are vital for the health and productivity of your cannabis plants. Use a well-draining, nutrient-rich soil mix and monitor the pH levels regularly. Additionally, consider implementing a feeding schedule tailored to the different growth stages, including the vegetative and flowering phases.

Watering Techniques

Proper watering is critical to prevent issues such as overwatering or underwatering. Implement a watering schedule based on the specific needs of your plants and the moisture retention capacity of your soil. Consider investing in a drip irrigation system for efficient and controlled watering.

Pest and Disease Management

Greenhouse cultivation doesn't exempt you from the risk of pests and diseases. Regularly inspect your plants for signs of infestation and implement preventive measures. Beneficial insects, like ladybugs and predatory mites, can be introduced to control pests naturally. Additionally, using organic pesticides and fungicides can help manage potential issues without compromising the quality of your harvest.

Training and Pruning Techniques

To maximize your greenhouse space and promote better light penetration, employ training and pruning techniques. Low-stress training (LST) and topping can control the height and shape of your plants, leading to a more even canopy and increased bud production.

Harvesting and Drying

Knowing the right time to harvest is crucial for obtaining potent and flavorful buds. Monitor the trichomes using a magnifying glass, and harvest when they turn milky or amber, depending on your desired effect. After harvest, implement a proper drying and curing process to preserve the quality of your cannabis.


Cultivating cannabis in a greenhouse provides a controlled and efficient environment for achieving high-quality yields. By paying attention to environmental conditions, strain selection, soil health, and implementing proper cultivation techniques, you can enjoy a successful cannabis harvest that reflects the dedication and care you put into your greenhouse cultivation.