A greenhouse offers you the unique opportunity to optimally control the environmental conditions for growing cannabis. Unlike outdoor cultivation, where you are at the mercy of the weather, in a greenhouse you can precisely adjust the temperature, humidity and light. This leads to even and healthy growth of your plants.

Temperature control is particularly important, as cannabis is sensitive to extreme heat or cold. With a greenhouse, you can keep the temperature constantly in an optimal range, which leads to better photosynthesis and ultimately higher yields. You can also regulate the humidity to prevent mold growth and other moisture problems.

Light is another crucial factor. In the greenhouse, you can ideally control the light conditions and use additional lighting to supplement the natural sunlight if necessary. This is particularly important in the shorter winter months to avoid interrupting growth and provide plants with a constant light cycle.

Extended growing season with the greenhouse

A greenhouse allows you to significantly extend the growing season. While traditional outdoor cultivation is heavily dependent on the seasons, in a greenhouse you can start growing in early spring and harvest until late fall. This gives you the freedom to carry out several growing cycles per year and maximize your harvest yields.

Thanks to the protected environment in the greenhouse, you can stay active even in colder months. The insulation keeps the heat inside so that the plants can thrive even at lower outside temperatures. You can also put the plants outdoors earlier or bring them into the greenhouse later to create the best conditions for each stage of growth.

The extended growing season also gives you the opportunity to try out different cannabis strains, which may have different flowering times. This allows you to be flexible with your growing plans and always get the best out of each season.

Protection from external influences when growing cannabis in a greenhouse

Another major advantage of growing cannabis in a greenhouse is the protection from external influences. Outdoors, your plants are exposed to many dangers, such as heavy rain, wind, pests and diseases. A greenhouse creates a barrier against these harmful influences and provides a controlled and safe environment for your plants.

Heavy rainfall can oversaturate the soil and suffocate the roots of your plants. Wind can damage or knock over the plants, while pests such as insects and rodents can eat the plants and transmit diseases. You are better protected from all these dangers in a greenhouse. The plants are safer and can concentrate fully on their growth, resulting in better quality and higher yields.

In addition, a greenhouse also offers protection from prying eyes and possible theft, which is especially important if you live in an area where cannabis cultivation is not widespread or possibly even illegal. With a greenhouse, you can grow discreetly and safely without attracting unwanted attention to your plants.

The right equipment for growing cannabis in a greenhouse

Choosing the right greenhouse for cannabis

Choosing the right greenhouse is the first and most important step in successfully growing cannabis. There are different types of greenhouses, which vary in size, material and structure. Glass and polycarbonate greenhouses are mainly suitable for growing cannabis, as they offer high light transmission and good insulation.

When choosing the size of the greenhouse, you should make sure that it offers enough space for the number of plants you want to grow. A greenhouse that is too small can quickly become overcrowded and restrict the plants' growth. At the same time, however, it should not be too large in order to keep the costs and effort for heating and lighting within limits.

Another important aspect is ventilation. Greenhouses with good ventilation systems allow better control of humidity and temperature. Automatic ventilation systems that open and close at certain temperatures are particularly practical.

Additional lighting for cannabis in the greenhouse

Even though a greenhouse provides plenty of natural light, additional lighting may be necessary, especially in the darker months. Cannabis needs a certain amount of light per day to grow and flower optimally. This is where LED lamps come into play, as they have proven to be particularly energy efficient and effective.

LED lamps are available in different spectrums and can therefore supplement natural sunlight. During the growth phase, plants need more blue light, while red light is preferred during the flowering phase. Modern LED systems allow the light spectrum to be adjusted according to the needs of the plants.

The lighting should be evenly distributed to ensure that all plants receive sufficient light. Reflective materials on the walls of the greenhouse can help to distribute the light evenly and increase efficiency.

Ventilation and air circulation in the cannabis greenhouse

Good ventilation and air circulation are crucial to the success of your cannabis grow in the greenhouse. Stagnant air can lead to a variety of problems, including mold growth and pest infestation. Therefore, it is important to install an effective ventilation system.

A ventilation system should include both supply and exhaust fans. Supply fans draw fresh air into the greenhouse from outside, while exhaust fans remove stale air to the outside. Ideally, these fans should be equipped with filters to keep out dirt and pests.

In addition to ventilation, recirculation fans ensure that the air inside the greenhouse remains in motion. This prevents the formation of damp patches and ensures that the plants are evenly supplied with CO2, which is necessary for photosynthesis.

Irrigation systems for growing cannabis in a greenhouse

An efficient irrigation system is essential for the successful cultivation of cannabis in a greenhouse. Drip irrigation systems are particularly popular as they ensure an even and precise water supply. These systems deliver water directly to the roots of the plants, saving water and minimizing the risk of overwatering.

Automatic watering systems are particularly practical as they reduce effort and ensure that plants always receive the right amount of water. These systems can be set to deliver water at specific times or depending on soil moisture.

In addition to irrigation, nutrient supply is also important. In hydroponic systems, plants are grown in a nutrient solution instead of soil. This method can lead to faster growth and higher yields, but requires close control of nutrient concentration and pH levels.

Growing and caring for cannabis in a greenhouse

Choosing the right cannabis strains for the greenhouse

Choosing the right cannabis strains is crucial to the success of your greenhouse cultivation. Not all strains are equally suitable for greenhouse cultivation. Sativa-dominant strains tend to grow taller and benefit from the extended growing period and space available in the greenhouse. However, they require more care and a longer flowering period. Indica-dominant strains, on the other hand, remain more compact and have a shorter flowering time, which makes them easier to care for.

Autoflowering strains, which flower independently of the light cycle, are also a good choice for greenhouses. They usually have a shorter lifespan and can provide multiple harvests per year. When selecting varieties, you should also pay attention to the specific requirements and characteristics, such as resistance to mold and pests, which can be particularly beneficial in a humid greenhouse environment.

Soil preparation and fertilization for cannabis in the greenhouse

Careful soil preparation is essential for healthy cannabis plants. The soil should be loose and well aerated to allow for optimal root growth. High-quality soil, rich in organic matter and nutrients, forms the basis for strong plants. Many gardeners mix their own soil to ensure that it contains all the necessary nutrients.

Compost, worm humus and well-rotted manure are excellent additions to increase soil fertility. It is also important to check the pH of the soil and adjust it if necessary to ensure that nutrients are available for the plants. A pH between 6.0 and 7.0 is ideal for cannabis.

Regular fertilization is also essential. During the growth phase, plants need more nitrogen, while during the flowering phase they have a greater need for phosphorus and potassium. Organic fertilizers are particularly gentle and support soil life, but mineral fertilizers can also be used to quickly compensate for specific nutrient deficiencies.

Planting time and regular care of cannabis in the greenhouse

The right planting time is crucial for the success of your cultivation. In a greenhouse, you can start growing in early spring when the days get longer and the temperatures rise. Germination is best done in small pots or growing cubes placed in a warm and humid environment. As soon as the seedlings are strong enough, they can be transplanted into larger pots or directly into the greenhouse soil.

Regular care is the secret to healthy and productive plants. This includes regular watering, making sure that the soil is evenly moist but not too wet. Excessive moisture can lead to root rot, while drought stress can impair plant growth.

Pruning and defoliating the plants promotes air circulation and the penetration of light into the interior of the plant, which leads to better flower formation. During the growth phase, side shoots should be removed to concentrate the plant's energy on the main shoots. During the flowering phase, it is important to remove dead leaves regularly to prevent mold growth.

Pest control is another important aspect of care. Even though the greenhouse offers some protection, pests such as spider mites, aphids and thrips can still cause problems. Regular inspections and the use of biological pesticides can help to keep the plants healthy.

Cannabis in the greenhouse odor

Preventing odor problems when growing cannabis

When growing cannabis in a greenhouse, the intense smell of the plants can be a significant problem, especially if your greenhouse is close to neighbors or public areas. Cannabis produces strong, distinctive aromas during the flowering period that can be easily detected. These odors come from the terpenes, the aromatic compounds in the plants that are also responsible for their therapeutic properties.

To prevent odor problems, it is important to make the greenhouse airtight. All cracks and openings should be sealed to prevent the odor from escaping. Special sealing materials and techniques can help to make the greenhouse as odor-tight as possible.

Another important step is the installation of a high-quality exhaust air system. This system should be able to efficiently filter and renew the air in the greenhouse without the odor escaping to the outside. Activated carbon filters are particularly effective here, as they neutralize odours before the air reaches the outside.

Tips for controlling odors in the greenhouse

In addition to sealing and using exhaust air systems, there are other measures you can take to control odors in the greenhouse. Here are some tips:

Activated carbon filters: these filters are one of the most effective methods of odor control. They work by binding and neutralizing the odor-causing molecules in the air. Place activated charcoal filters in your exhaust air system to ensure that any odors that escape are filtered out.
Odour neutralizers: There are various products on the market that have been specially developed to neutralize odours. These can be used in combination with your ventilation system to further minimize odor. Products such as ONA gel or odour-neutralizing sprays can be helpful.
Plants to reduce odor: Certain plants can also help mask the smell of cannabis. Plants such as lavender, rosemary and mint have strong scents of their own that can mask the smell of cannabis. These plants can be strategically placed in and around the greenhouse.
Regular cleaning: Keep your greenhouse clean and free of dead leaves and plant debris, which can further contribute to the odor. Regular cleaning prevents the accumulation of organic material that can rot and increase the odor.
Humidifiers and ozone generators: These devices can also contribute to odor control. A humidifier keeps the humidity at an optimal level, while an ozone generator breaks down odor molecules. However, both devices should be used with caution, as they can harm plants and people if used incorrectly.
Airtight storage: If you store harvested cannabis in a greenhouse, make sure it is kept in airtight containers. This will prevent the odor from escaping and spreading throughout the greenhouse.

By combining these measures, you can effectively manage odor problems when growing cannabis in a greenhouse. Good odor control not only ensures a more pleasant environment, but also helps to avoid unwanted attention.

Cannabis in an outdoor greenhouse

Outdoor greenhouses for growing cannabis in the garden

Growing cannabis in an outdoor greenhouse offers many benefits and can be an ideal solution for growers who want to combine the natural benefits of outdoor growing with the added protection of a greenhouse. An outdoor greenhouse in the garden provides a controlled environment that offers plants protection from extreme weather conditions and pests, while allowing them to make the most of natural sunlight and fresh air.

Choosing the right location for your outdoor greenhouse is crucial. It should be in a place that receives plenty of sunlight throughout the day and is well protected from strong winds. The soil should be well-drained to avoid waterlogging, which could cause root rot. If the soil in your garden is not ideal, you can use raised beds or large planters to create optimal conditions.

An outdoor greenhouse can be constructed from a variety of materials. Glass and polycarbonate greenhouses are particularly popular as they are robust and durable. Foil greenhouses are a cheaper option and easy to install, but may not offer the same protection and insulation as their sturdier counterparts.

Pros and cons of outdoor greenhouse growing

Growing cannabis in an outdoor greenhouse has its own pros and cons that you should consider before deciding on this method.

Advantages:

Natural light source: The outdoor greenhouse utilizes natural sunlight, which is ideal for growing cannabis. Sunlight is free and provides the full spectrum of light that plants need.
Protection from the elements: A greenhouse protects plants from extreme weather conditions such as heavy rain, hail or frost. This can be particularly beneficial in regions with unpredictable weather.
Extended growing season: Similar to an indoor greenhouse, an outdoor greenhouse allows you to extend the growing season. You can start earlier in the year and harvest later in the fall.
Protection from pests: A well-constructed greenhouse can keep out many pests that could be a problem in outdoor growing. This reduces the need for pesticides and encourages more natural growing.
Better control over the environment: even though it's an outdoor greenhouse, you still have some control over temperature and humidity, which reduces the risk of plant disease and mold.

Disadvantages:

Higher initial costs: building an outdoor greenhouse can be more expensive than simply growing outdoors. The cost of materials, construction and any necessary permits should be taken into account.
Regular maintenance: A greenhouse requires regular maintenance to ensure that it remains in good condition. This includes cleaning the walls, checking for cracks or damage and maintaining the ventilation systems.
Energy consumption: If you use additional lighting or heating in your greenhouse, energy costs may increase. This should be taken into account when planning your cultivation.
Space limitations: Depending on the size of your garden, space for a greenhouse could be limited. A greenhouse that is too small can restrict the growth of the plants.
Visibility and security: A greenhouse can be visible in the garden and may attract unwanted attention. Security measures, such as a lockable greenhouse, should be considered.

By weighing up these pros and cons, you can decide whether an outdoor greenhouse is the right choice for your cannabis grow. However, with the right planning and care, you can reap the many benefits and achieve a successful harvest.

When to grow cannabis in a greenhouse?

Best time for cultivation

The right time to grow cannabis in a greenhouse is crucial to ensure a healthy and productive harvest. In general, cultivation can begin in early spring, as soon as the days get longer and temperatures rise. The advantage of a greenhouse is that you can start earlier, regardless of the weather conditions outside.

In most regions, this means that you can start germinating your seeds from March or April. Germination is best done in small pots or growing cubes that are placed in a warm and humid environment. A heated growing bed or heat mats can be very helpful here to ensure an even temperature and promote germination.

As soon as the seedlings are strong enough and the danger of frost has passed, they can be transplanted into larger pots or directly into the greenhouse soil. Make sure to gradually acclimatize the young plants to the stronger sunlight and lower night temperatures to avoid stress.

Extending the season with the greenhouse

A major advantage of growing cannabis in a greenhouse is the ability to extend the growing season. While traditional outdoor cultivation is heavily dependent on the seasons, you can grow in a greenhouse almost all year round.

In spring, the greenhouse allows you to start earlier as the plants are protected from cold and frost. You can start growing before the outside temperatures consistently rise above 10°C. The greenhouse retains the heat and creates an ideal microclimate for your plants to grow.

In the fall, on the other hand, you can delay the harvest time. While the outside temperatures drop and the days get shorter, the greenhouse remains warm enough to support the growth of the plants. Heaters or frost protection lamps can help to keep temperatures at an optimum level.

This extended growing season gives you the opportunity to achieve several harvests per year. Especially when using autoflowering strains, which flower independently of the light cycle, you can continuously grow and harvest new plants.

By taking advantage of a greenhouse, you not only maximize your yields, but you can also grow a greater variety of strains. This gives you the flexibility to try out different cannabis strains and optimize your growing methods.

Cannabis in a mini greenhouse

Advantages and challenges

Growing cannabis in a mini-greenhouse offers a number of benefits, but also comes with some challenges. A mini-greenhouse is ideal for growers with limited space, for example on a balcony, terrace or in a small garden.

Advantages:

Space-saving: Mini greenhouses take up very little space and are therefore perfect for urban environments or small gardens.
Cost savings: They are generally cheaper to purchase and maintain than large greenhouses.
Ease of use: Due to their size, they are easier to install and maintain. It is also easier and quicker to control the environmental conditions.
Discretion: Mini greenhouses can be placed inconspicuously in urban or populated areas, providing more privacy.
Mobility: Smaller greenhouses are often portable and can be easily relocated as needed.

Challenges:

Limited space: limited space can restrict plant growth and requires careful planning to utilize space efficiently.
Temperature control: Due to the small size, mini-greenhouses can heat up or cool down more quickly, requiring careful monitoring of the temperature.
Air circulation: Good air circulation is more difficult to achieve in small greenhouses, which increases the risk of mold and pests.
Fewer plants: Due to the limited space available, fewer plants can be grown, limiting crop yields.

Tips for growing in small greenhouses

To get the most out of your mini greenhouse, there are some tips and tricks that can help you grow cannabis successfully:

Optimal use of space: make efficient use of the available space by using vertical growing techniques. Hanging racks or plant stands can help maximize vertical space.
Choose compact strains: Opt for compact cannabis strains or autoflowering strains that stay smaller and require less space. These strains are ideal for growing in cramped conditions.
Temperature and humidity control: Invest in a thermometer and hygrometer to keep an eye on the temperature and humidity. Air vents or small fans can help improve air circulation and ensure stable conditions.
Lighting: Additional lighting may also be necessary in a mini-greenhouse. LED lights are energy efficient and generate less heat, which is an advantage in small spaces. Make sure that the lighting is evenly distributed.
Regular care: Due to the limited space, regular care is particularly important. Prune your plants regularly to control growth and ensure good air circulation.
Automated systems: Consider installing automated watering and aeration systems. These systems can significantly reduce the amount of care required and provide consistently optimal growing conditions.
Discretion: If discretion is important, make sure your mini-greenhouse is well hidden or in a low-visibility corner. Odour filters and neutralizers can help minimize the characteristic cannabis smell.

By following these tips, you can grow healthy, high-yielding cannabis plants in a mini-greenhouse. Despite the limited size, a mini-greenhouse offers many opportunities to get creative and make the most of your limited space.

Drying cannabis in a greenhouse

Ideal drying conditions

Drying cannabis is a crucial step to ensure the quality and potency of the harvest. After harvesting, the flowers must be dried slowly and evenly to preserve the full aroma and active ingredients. Ideal drying conditions are important to prevent mold growth and ensure the best possible quality.

The ideal drying conditions for cannabis are a temperature of 18-24°C and a relative humidity of 45-55%. These conditions allow the flowers to dry slowly and evenly without drying out too quickly and becoming brittle.

A dark, well-ventilated room is ideal for drying. The greenhouse can serve as such a room if it is equipped accordingly. Blackout films or curtains can be used to reduce the light, as light can break down the sensitive cannabinoids and terpenes in the flowers.

Air circulation is another important factor. Still air can lead to moisture buildup and mold growth. Fans that gently move the air help to distribute moisture evenly and prevent mold from forming. However, it is important that the air is not blown directly onto the flowers as this can cause them to dry too quickly.

Avoiding mold and loss of quality

To prevent mold growth and loss of quality, some additional measures are required:

Regular inspection: check the flowers regularly during the drying process for signs of mold or excessive drying. Remove affected areas immediately to prevent spread.
Humidity control: Use a hygrometer to monitor the humidity in the drying room. If necessary, a dehumidifier can be used to keep the humidity at an optimum level. Alternatively, a humidifier can be used if the air is too dry.
Correct hanging: Hang the flowers in a well-ventilated area so that they are not too close together. This allows better air circulation and prevents the accumulation of moisture.
Avoid touching: Touch the flowers as little as possible during the drying process to avoid damaging the trichomes (the resin crystals on the flowers). The trichomes contain most of the active ingredients and aromas that you want to preserve.
Slow drying: Drying should be done slowly, ideally over a period of 7-14 days. Drying too quickly can lead to a loss of aroma and potency, while drying too slowly increases the risk of mold growth.
After drying: Once the flowers are dry, they should be stored in airtight containers at a relative humidity of 58-62%. A curing process of at least two weeks can further enhance flavors and maximize potency.

By following these drying techniques, you will ensure that your cannabis flowers reach their full potential. Careful drying is crucial to avoid mold and preserve the quality of your cannabis. With the right preparation and care, you can achieve a first-class harvest that impresses in terms of both potency and aroma.

Tomatoes and cannabis in the greenhouse

Similarities and differences in cultivation

Growing tomatoes and cannabis in a greenhouse can be an interesting and beneficial combination. Both plants have similar requirements, but there are also some differences that need to be taken into account.

Similarities:

Light requirements: both tomatoes and cannabis need a lot of light to grow optimally. A greenhouse offers the opportunity to meet this need through natural sunlight and, if necessary, additional lighting.
Temperature: Both plants thrive best at similar temperatures. During the day they prefer temperatures between 20-28°C and at night between 15-20°C.
Air circulation: Good air circulation is important for both plants to prevent mold and disease. Fans in the greenhouse can help to keep the air moving.
Watering: Tomatoes and cannabis need regular but not excessive watering. The soil should be moist but not wet to avoid root rot.
Nutrients: Both plants benefit from a balanced supply of nutrients. Organic fertilizers are ideal to encourage soil life and keep plants healthy.

Differences:

Growth cycle: cannabis has a clear growth and flowering cycle depending on the strain, whereas tomatoes can produce flowers and fruit continuously. Adjusting the light cycles in the greenhouse can be a challenge.
Space requirements: Cannabis can grow very large depending on the variety and growth phase, while tomatoes usually remain more compact. Careful planning and positioning in the greenhouse are necessary to ensure that both plants have enough space.
Pest infestation: While cannabis and tomatoes can have similar pests, the specific susceptibilities can vary. Regular inspections and good care are necessary to detect and treat problems early.

Advantages of mixed cultivation

Growing tomatoes and cannabis together in a greenhouse can offer several advantages:

Optimal use of space: by combining the two crops, you can make more efficient use of the available space in the greenhouse. Tomatoes, for example, can grow along the sides or on climbing supports, while cannabis has more space in the center for vertical growth.
Natural pest control: Certain tomato varieties can help keep away pests that could also infest cannabis. Conversely, the terpenes and essential oils of cannabis can deter pests that infest tomatoes.
Diversification: By diversifying your greenhouse, you reduce the risk of crop failure due to pests or diseases that favor a particular plant species. A mixed crop can lead to a more stable and healthier ecosystem.
Improved soil quality: The different root systems of tomatoes and cannabis can penetrate and improve the soil in different ways. This leads to better soil drainage and balanced nutrient distribution.
Increase crop diversity: With a mixed crop, you can not only enjoy a greater variety of plants, but also extend the harvest period. While tomatoes bear fruit continuously, you can harvest cannabis several times a year, especially if you grow autoflowering varieties.
Aesthetic and practical benefits: A greenhouse with a mixed crop not only looks more attractive, but also offers practical benefits. The different heights and growth forms of the plants can make optimal use of the available light and air space.

By growing tomatoes and cannabis together in a greenhouse, you can reap the benefits of both crops and create a healthier, more productive growing system. With the right planning and care, you can successfully establish a mixed crop that is both ecologically sound and high-yielding.

Conclusion

Growing cannabis in a greenhouse offers numerous benefits that make it an attractive option for growers. From better control over environmental conditions to the ability to extend the growing season, a greenhouse allows for an optimal growing environment for your plants. By protecting them from extreme weather conditions and pests, you can achieve healthier and higher yielding plants.

Careful selection of the right equipment - from the right greenhouse and additional lighting to efficient ventilation and irrigation systems - is crucial to the success of your grow. By choosing suitable cannabis strains and paying attention to soil preparation and fertilization, you lay the foundation for a successful harvest.

Dealing with odor problems and drying the harvest correctly are important aspects that you should not neglect. With the right odor control measures and optimal drying conditions, you can ensure the quality and potency of your cannabis flowers and prevent mold growth.

For growers with limited space, the mini-greenhouse offers a flexible and efficient solution. Despite the challenges of limited space, healthy and high-yielding cannabis plants can thrive in small greenhouses through clever use and careful care.

The combination of cannabis and tomatoes in the greenhouse offers interesting opportunities for mixed cultivation. By utilizing the different growing needs and advantages of both plants, you can not only increase crop diversity, but also improve soil quality and promote natural pest control.

Overall, growing cannabis in a greenhouse is a worthwhile investment that offers many benefits for beginners and experienced growers alike. With the right planning, equipment and care, you can optimally control the conditions and achieve high-quality yields. Whether you're growing as a hobby or aiming for larger-scale production, a greenhouse gives you the control and security you need to be successful.

Happy growing!

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Fachautor und Biochemier Niklas Bergmann

Niklas Bergmann, Fachautor

Freut euch auf die Insights von unserem Biochemiker Niklas Bergmann! Mit seinem tiefen Verständnis für alles, was mit Hanf zu tun hat, liefert er euch die neuesten und coolsten Infos direkt in euer Feed. Schnörkellos und klar verpackt er das komplexe Thema Cannabinoide und macht es für euch easy zugänglich. Mit Niklas an der Spitze unseres Wissens-Teams seid ihr immer top informiert.