Growing cannabis in a greenhouse: A complete guide from start to finish

13. 12. 2023

Growing cannabis in a greenhouse can be a fascinating adventure for gardeners and growers alike. In this article, we'll take you through the process of growing cannabis in a greenhouse from start to harvest, giving you important information, tips and techniques. Does cannabis grow faster in a greenhouse? Which substrate to choose? Can pests attack cannabis in the greenhouse? Then read on to find out how to grow cannabis successfully in a greenhouse.

Why grow cannabis in a greenhouse?

Greenhouse cultivation is a way of growing cannabis plants in artificial conditions. A greenhouse is a building with transparent walls and a roof that allows light to pass through while providing control over the indoor environment.

There are several reasons to grow cannabis in a greenhouse:

Control over the environment: a greenhouse allows for careful control over the environment, including temperature, humidity and lighting, resulting in optimal conditions for cannabis growth.

Faster growth: in a greenhouse, plant growth is accelerated due to stable conditions, which can lead to an earlier harvest.

Extended season: thanks to the greenhouse, the growing season can be extended, which is particularly beneficial in areas with a shorter growing season.

Protection against pests and diseases: a greenhouse provides a physical barrier against pests and can reduce the risk of disease.

Quality harvest: growing in a greenhouse can lead to a better quality harvest with a higher content of active substances.

Protection from adverse weather conditions: a greenhouse protects plants from extreme weather conditions such as storms, hail or too strong sunlight.

Growing cannabis in a greenhouse step by step

Preparation and planning

Choosing a suitable location for the greenhouse:

Choose a location with sufficient sunlight. Optimally, the greenhouse should face south so that it receives as much sunlight as possible during the day.
Consider the location also with regard to the distance to a water source for watering the plants.

Selecting suitable varieties of cannabis to grow in the greenhouse:

Choose varieties that are suitable for greenhouse cultivation and suit your needs.
Find out the light, temperature and humidity requirements of each variety.

Arrangement and spacing of plants:

Decide how to space the plants in your greenhouse. Make sure that each plant will have enough room to grow.
Consider using pots to make handling and caring for the plants easier.

Getting started

Maintain proper light, temperature and humidity:

Cannabis plants need plenty of light to grow. Most varieties require at least 12 hours of light per day during the growing season. If natural light is not enough, consider using artificial lighting.
Keep the temperature between 20-30 °C during the growing season and 18-24 °C during the flowering phase.
Control humidity, which can prevent mould and rot problems. Optimum relative humidity is between 40-60%.

Suitable substrate for growing cannabis in a greenhouse:

Choose a good quality substrate with good drainage and sufficient moisture retention.
Many cannabis growers prefer mixed soil or substrates specifically designed for cannabis.

Germination and growth stages:

Allow the seeds to germinate in suitable conditions, for example in a germination tray with a damp paper towel.
Once the seedlings have formed their first true leaves, transfer them to pots or soil in the greenhouse.

Caring for the plants

Watering, fertilizing and proper care:

Watering: the soil must be kept evenly moist but not waterlogged. Watering depends on the size of the plant and the stage of growth. Water regularly and in small amounts.
Fertilisation: use a good quality fertiliser designed for growing cannabis. Follow the recommended doses and fertilisation cycles for each stage of growth.
Plantcare: check the plants regularly and remove any wilted leaves.

Protection against pests and diseases:

Check the plants regularly and keep the greenhouse clean. Prevention is the key to reducing pests and diseases.
In the event of infection or infestation, use safe and appropriate means of protection such as organic pesticides or fungicides.

Growth stages and what to expect during them:

The vegetative phase: at this stage, the plants grow leaves and branches. Expect rapid growth and an increased need for light and nutrients.
Flowering phase: plants move into thebudding phase. The photoperiod becomes shorter and the formation of the buds requires specific nutrients.

Harvesting and drying

Signs for the start of harvest and method of cutting:

Cannabis plants need to be harvested at the right time to get the maximum content of active substances such as CBD. Signs that cannabis needs to be harvested include the maturing of the buds and the trichomes turning amber or milky.

Use a sharp pair of scissors or clippers to cut the stems. Harvest the canes gradually to put as little stress on the plants as possible.

After harvesting, hang the cannabis sticks in a dark, dry place where the temperature and relative humidity are maintained at optimum levels. The humidity of the flowers should drop to approximately 55-65 %. Drying can take up to several weeks.

Store the harvested buds in airtight containers to protect them from light and air. Keep them in a cool, dry place to preserve their quality.

A few words in conclusion

Growing cannabis in a greenhouse is a complex process that requires careful preparation, skill and patience. Every step has an impact on the final result, from choosing the right location and varieties to providing a suitable environment, caring for the plants and harvesting. Proper care and attention to detail are the keys to achieving healthy plants and a quality harvest. Growing cannabis in a greenhouse can be a rewarding and enriching experience.

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