Growing hemp indoors: a guide

Hanfanbau im Zimmer: eine Anleitung

Niklas Bergmann, M.A.

Biochemiker, Fachautor

Inhaltsverzeichnis: Growing hemp indoors: a guide

Ready to start your own green wonder at home? Great, because we're jumping straight into the world of growing hemp indoors. Hemp, a plant with a long history and multiple uses, can transform your home into a green oasis. Growing hemp at home may sound challenging at first, but with the right information it will be an exciting project!

Legal aspects of hemp cultivation

Overview of the legal situation

New in the legal code: from April 1, things will be greener in Germany. Adults will then be allowed to possess up to 50 grams of cannabis for personal use at home and up to 25 grams when out and about. But the coolest thing? You can now grow your own - up to three plants per person. Now that's news, isn't it?

Meaning for hobby gardeners

For all hobby gardeners among us, this means that we can officially become gardeners as long as we stick to a few rules. Growing at home or in special cultivation associations - everything is fine as long as we follow the rules. Why all the effort? Quite simply: to keep the black market small, to ensure cannabis quality and, above all, to protect our kids. So, before you plant the seeds, read up on the do's and don'ts.

In short, the new law opens doors for a more legal, safer cannabis culture in Germany. It's a big step towards responsible cannabis use, with the clear aim of better protection, education and limiting the illegal trade. As budding hobby botanists, we should inform ourselves about the exact details - a look at the official websites of the Federal Government or the Federal Ministry of Health sheds light on the dark and ensures that our green hobby is on the safe side.

Choosing the right hemp variety for growing indoor plants

Criteria for selection

Space requirements and growth height: Not every hemp variety is the same. Some stretch upwards, while others remain compact. For cultivation in a limited space, as is often the case with indoor cultivation, varieties that do not grow too tall are ideal.

Flowering time: Some cannabis strains need more time to reach the flowering stage. If you are impatiently waiting for your harvest, you should choose a strain with a short flowering time.

Yield: Think about what's more important to you: quality or quantity? High-yielding varieties can be tempting, but it's often the lower-yielding varieties that produce higher quality flowers.

Resistance to pests and diseases: Some varieties are more robust and resistant to environmental conditions. For beginners, such a variety can mean fewer worries.

Recommendations for beginners

Auto-flowering varieties: These plants start flowering automatically, regardless of the light conditions. They are ideal for beginners as they require less care and are usually ready to harvest after 8-10 weeks.

Indica-dominant strains: They tend to stay smaller and bushier, making them a good choice for growing in small spaces. They also often have a shorter flowering time than sativa-dominant strains.

CBD-rich strains: If your interest is more in the medicinal properties of cannabis, CBD-rich strains might be a good choice. They offer many of the health benefits of cannabis, without the high THC content associated with the psychoactive effect.

Choosing the right cannabis strain for your indoor grow is key to a successful grow. Consider the above criteria and recommendations to find a strain that best suits your needs and grow space. With the right strain and a little care, you'll soon be enjoying the fruits of your labor.

Cannabis growing and hemp cultivation basics

Preparing the grow room

Cleanliness is key: before you even start, make sure your grow room is spotlessly clean. Cannabis is susceptible to pests and diseases; a clean environment minimizes risks.

Ventilation: Good air circulation is crucial. It helps keep out mold and other airborne diseases and regulates the temperature. A small fan can work wonders.

Light sealing: Cannabis needs alternating light and dark phases to flower. Make sure that your grow room can be completely darkened during the dark phases.

Temperature and humidity: Ideal temperatures are between 20°C and 25°C during the light phases and slightly cooler when it is dark. Humidity should be between 40-60% during the growth phase and slightly lower during the flowering phase.

Necessary equipment for cultivation

Light: One of the most important investments. LED lights or special grow lights are energy efficient and produce little heat. Choose a lamp that suits your growing space.

Pots: Make sure the pots are large enough for the full-grown plant and that they have good drainage to avoid waterlogging.

Soil and fertilizer: Cannabis prefers an airy, well-drained soil with a pH between 6 and 7. Organic soil and special cannabis fertilizer can provide your plants with all the nutrients they need.

Measuring equipment: Invest in a good thermometer/hygrometer to keep an eye on temperature and humidity. A pH meter for the soil and irrigation water is also helpful.

Ventilation system: A simple fan is sufficient for small rooms. For larger grow rooms, an exhaust air system with a carbon filter may be necessary to minimize odours and maintain air quality.

The grow box for hemp: an indispensable tool

When you embark on the adventure of growing cannabis or hemp in your own home, you quickly realize that a grow box is more than just a useful tool - it's an essential tool that can make the difference between a thriving garden and a frustrating experiment. Why is a grow box so important and how do you choose the right one? Let's find out.

Benefits of a grow box

A grow box offers the perfect solution to some of the biggest challenges of indoor growing: creating and maintaining an ideal environment for your plants. It allows you to precisely control important growth factors such as light, temperature and humidity. This is crucial to keeping your plants healthy and maximizing their yields.

Another significant advantage is the ability to grow all year round. Your plants are protected from external weather conditions, which means you are not dependent on the seasons. This consistency not only allows for regular harvests, but also the freedom to experiment with different varieties and growing methods.

Discretion is also a key aspect, especially if you live in an environment where your hobby may not be well received. A grow box helps to hide your plants from prying eyes and can be equipped with filters that neutralize odors, so your privacy is maintained.

A grow box also increases the efficiency and productivity of your cultivation. Equipped with modern LED lamps that provide optimum light with low energy consumption, it supports rapid plant growth and promotes abundant harvests without driving up electricity costs.

Choosing the right grow box

When choosing the right grow box, you should consider a number of factors: Size, lighting, ventilation system and expandability. The size of your grow box should not only fit your available space, but also take into account the selected plant varieties and their growth expectations. Lighting is another critical factor; look for solutions that offer a full spectrum to ensure your plants receive all the light wavelengths necessary for growth. An efficient ventilation system is crucial to prevent mold growth and ensure a stable environment. Lastly, you should consider whether you want a grow box that you can expand later to keep up with your growing interest in cannabis cultivation.

A carefully selected grow box is the cornerstone of successful indoor cannabis or hemp cultivation. It not only provides the optimal environment for your plants, but also the security and discretion you need to enjoy your hobby worry-free.

Growbox mit einer kleinen Hanfpflanze in einem Topf, Licht und einem Belüfter

Recognizing male and female plants

Differences between male and female plants

Male plants develop pollen sacs that look like small, round balls hanging from the stems of the plant. These pollen sacs open to release pollen when they are ripe.

Female plants, on the other hand, develop so-called stigmas, which are hair-like structures that protrude from the buds called calyxes. These stigmas are often white or orange and serve to trap pollen from the air. The female plants develop the trichome-covered flowers that are desirable for consumption.

Methods for identification

Observe pre-flowering: The surest way to determine the sex of a cannabis plant is to observe pre-flowering, which occurs about 4-6 weeks after germination. In male plants you can see the development of the pollen sacs, while in female plants you can see the stigmas.

Lightcycle: Male plants often show signs of sexual maturity a few days before female plants. Changing the light cycle to 12 hours of light and 12 hours of darkness can initiate the flowering phase and help to recognize the sex earlier.

Genetics and strain: Some cannabis strains and feminized seeds significantly reduce the risk of male plants. Feminized seeds are bred to produce almost exclusively female plants.

Early gender recognition is crucial for growers aiming for high quality and quantity of cannabis flowers. By removing male plants from your grow, you can prevent your female plants from being pollinated and developing seeds, resulting in a pure and potent harvest.

The time required to grow cannabis indoors

Planning and daily care

Planning phase: Before you can get started, you first need a plan. Your future greenery needs a cool spot to chill out, the right soil and, of course, the perfect light. Grab a coffee, sit down and make a plan - this can take anywhere from a few hours to a day, depending on how big you want to think.

Daily ritual: Once your babies are in the ground, they need daily love and attention. We're talking a quick date with your plants to check if they need water, how they're doing and if they have any unwanted guests. Plan 10-30 minutes a day, depending on how many plants you have and how much love they need.

Long-term care and attention

Training and pruning: Your green friends like a bit of a workout - it keeps them fit and increases the harvest. Every few weeks you should take time to prune and train them. It's not a marathon, but you should plan a few hours, especially if you have a lot of plants.

Keep an eye ongrowth and flowering: Over the weeks and months, you need to keep an eye on the growth of your plants, adjust the light cycle and decide when it's time to harvest. This long-term care may only take a few minutes a day, but it requires constant attention.

Harvest time: When the time comes, your plants need you more than ever. The harvest itself and the initial processing can take a few days, depending on how busy you are. After that, your plants deserve a cool, dark place to dry, which can take a few weeks but requires little work on your part.

In short, growing cannabis is a hobby that takes as much time as you are willing to give. Daily care is done quickly, but long-term care and special moments like harvesting need your full attention. But hey, at the end of the day, it's all worth it when you get to enjoy the fruits - or in this case, the buds - of your labor.


So, folks, hand on heart: growing hemp at home is more than just a trend. It's your chance to dive deep into the green world without leaving the couch. Thanks to new legislation from April 1, it is now possible to legally grow up to three plants for personal use. For us, this means: more quality, less black market and a big plus for safety.

Choosing your cannabis strain? Pretty crucial, if you ask me. Whether you're looking at size, flowering time or resilience, make it your mission to find the perfect strain for your four walls. For the newbies among us: autoflowering and indica strains are the uncomplicated buddies that make it easy for you to get started.

Now to the heart of your project: the grow room. A clean, well-ventilated grow box with the right light and room climate is the be-all and end-all. It's like a VIP area for your plants, where they can hang out and grow in peace - without stress, without drama.

Determining the sex of your plants is as important as the first sip of coffee in the morning. Because only the ladies will produce the longed-for flowers. Separating the boys from the girls early on will save you a lot of headaches later on.

Let's be honest: time and love are what your plants really need. Whether you check on them every day or give them a helping hand every few weeks, your green fingers will determine their success. And when the time finally comes, the harvest will be worth all your effort.

At the end of the day, it's all about doing your thing. Be it out of curiosity, for self-sufficiency or simply to green up your home - growing your own hemp is an exciting project that will not only give you green fingers, but also a lot of fun and experience. Let's grow!

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.