Germination is the first step in the life cycle of a cannabis plant. It begins when the seed absorbs moisture and starts to germinate. During this process, the hard seed coat breaks open and the first root, also known as the radicle, begins to grow. This process usually takes between 3 and 10 days. Germination is crucial as it lays the foundation for a healthy plant.

Methods for germinating cannabis seeds

There are various methods to successfully germinate cannabis seeds. Here are some of the most popular:

Moist paper towel

Steps:
1. Place the seeds between two damp paper towels.
2. Place the paper towels on a plate and cover them with another plate to retain the moisture.
3. Make sure that the temperature remains constant between 20-25°C.
4. Check the seeds daily and keep the paper towels moist.
Advantages: Simple and inexpensive, high success rate.

Direct planting in the growing medium

Steps:
1. Plant the seeds directly into the growing medium (e.g. soil or coconut fibre) about 1-2 cm deep.
2. Keep the medium moist, but not wet.
3. Make sure that the temperature remains constant between 20-25°C.
Advantages: Less stress for the roots as no replanting is required.

Germination in a glass of water

Steps:
1. Place the seeds in a glass of lukewarm water.
2. Leave the seeds in the water for 24-48 hours until they swell and the first roots appear.
3. Carefully plant the germinated seeds in the growing medium.
Advantages: Simple monitoring of the germination process, promotes rapid germination.

Optimal conditions for germination

Certain conditions must be met to ensure successful germination:

Temperatur

Optimal: 20-25°C
Tipp: Use a heating mat or place the seeds in a warm room to ensure constant temperatures.

Feuchtigkeit

Optimal: Damp, but not wet environment
Tipp: Cover the seeds or growing medium to retain moisture and check the moisture content regularly.

Dunkelheit

Optimal: Dark place
Tip: Germinate the seeds in a dark cupboard or cover them with a cloth to exclude light.

Fresh seeds

Optimal: Use fresh seeds to maximise the germination rate.
Tip: Store seeds in a cool, dry place to preserve their freshness.

By observing these conditions and using the correct method, you can ensure that your cannabis seeds germinate successfully and produce healthy seedlings.

Cannabis growth phase: duration, light, temperature and humidity

Transition from germination to the vegetative phase

After germination, the vegetative growth phase of the cannabis plant begins. This transition is crucial, as the plant expands its root system and develops strong stems and leaves during this phase. The vegetative phase can last from several weeks to months, depending on the variety and cultivation goal. Good care during this phase lays the foundation for a successful Flower.

Important factors in the vegetative phase

Light in the growth phase

Light is one of the most important factors for the growth of cannabis plants in the vegetative phase.

Lichtdauer: Cannabis ideally needs 18 hours of light and 6 hours of darkness per day during this phase.
Lichtart: LED and HPS lamps are widely used. LEDs are more energy efficient and generate less heat, while HPS lamps often offer a higher light intensity.
Lichtstärke: A high light intensity promotes vigorous plant growth. Make sure that the light source is close enough to the plants to provide sufficient light, but not so close that it burns the plants.

Nutrients and cannabis fertiliser

During the vegetative phase, cannabis plants require a balanced supply of nutrients.

Important nutrients: Nitrogen (N) is the most important nutrient in this phase, as it promotes leaf growth. Phosphorus (P) and potassium (K) are also necessary, but in smaller quantities.
Düngemittel: Use special fertilisers for the vegetative phase that are rich in nitrogen. Be sure to follow the manufacturer's instructions to avoid over-fertilisation.

Water requirement in the vegetative phase

An appropriate water balance is crucial for growth.

Bewässerung: Keep the soil evenly moist, but avoid waterlogging. A good drainage system is important to prevent root rot.
pH-Wert: The pH value of the water should be between 6.0 and 7.0. An incorrect pH value can impair the plant's nutrient uptake.

Temperature and humidity

The right temperature and humidity are essential for healthy plant growth.

Temperatur: Keep the temperature between 20-28°C during the day and not below 18°C at night. Temperatures that are too high can inhibit growth, while temperatures that are too low slow it down.
Luftfeuchtigkeit: In the vegetative phase, the humidity should be between 40-70%. Humidity that is too low can impair plant growth, while humidity that is too high increases the risk of mould growth.
Luftzirkulation: Good air circulation is important to prevent mould growth and to strengthen the plants. Use fans to keep the air in your grow room moving.

By paying attention to these factors, you can ensure that your cannabis plants grow healthy and vigorous in the vegetative phase, which forms the basis for a successful Flower.

Pruning and training techniques in the cannabis growth phase

Why pruning is important

Pruning is an essential part of cannabis cultivation that helps to optimise plant health and yield. Pruning removes unwanted or weak parts of the plant, which improves the flow of energy to the remaining, more productive parts. This leads to stronger plants, better light penetration and increased yield. Pruning also helps to control growth and improve plant structure.

Techniques for trimming

There are various techniques that can be used when pruning cannabis plants, each with their own benefits. Here are the three most common methods:

Low Stress Training (LST)

Low Stress Training (LST) is a technique in which the branches of the plant are carefully bent and fixed to promote more even and bushy growth.

Advantages: Increases the number of flowering points, improves light distribution, minimises the risk of plant stress.
Durchführung:
1. Select young, flexible branches.
2. Carefully bend the branches downwards and secure them with soft wires or plant ties.
3. Repeat the process regularly to control growth and achieve an even plant density.

Screen of Green (SCROG)

Screen of Green (SCROG) is a technique in which a net is stretched over the plants through which the branches grow. This results in an even, flat plant structure.

Advantages: Maximises yield per area, promotes even light distribution, facilitates care and harvesting.
Durchführung:
1. Stretch a net at the height of the plant tips.
2. Guide the branches through the net and distribute them evenly.
3. Cut off all unnecessary shoots and leaves below the net to concentrate the energy on the upper inflorescences.

Topping and fimming

Topping and fimming are techniques in which the tip of the plant is removed to direct growth into several main branches.

Topping: The top tip of the plant is completely removed.
- Advantages: Promotes the growth of two new main branches, improves light penetration.
- Durchführung: Cut off the top of the plant with sterile scissors or a knife.
Fimming: A modified form of topping in which only about 75% of the tip is removed.
- Advantages: Leads to several new shoots at the top, less stressful for the plant.
- Durchführung: Cut off about 75% of the top tip, leaving a few leaves and shoots.

Light in the cannabis growth phase: How long and which lighting?

Importance of light in the growth phase

Light is one of the most important resources for the growth of cannabis plants. During the growth phase, light is essential for photosynthesis, the process by which plants convert light energy into chemical energy in order to grow and develop. Sufficient and correct light promotes strong root growth, robust stems and dense foliage, which lays the foundation for a successful flowering phase.

Optimum light cycles

The light cycle in the growth phase is crucial for the healthy growth of cannabis plants.

Lichtdauer: In the vegetative phase, cannabis plants ideally require 18 hours of light and 6 hours of darkness per day. This cycle simulates the long summer days under which cannabis grows in nature.
Lichtintensität: Cannabis plants need intense light to grow vigorously. Make sure that the light source is close enough to the plants to provide enough light, but not so close that it burns the plants.

Types of lighting

There are different types of lighting that can be used for growing cannabis plants in the growth phase. Each has its own advantages and disadvantages.

LED-Beleuchtung

Advantages:
- Energy-efficient and durable
- Low heat generation, which minimises the risk of heat damage
- Adjustable spectra that can be adapted to the needs of the plants
Disadvantages:
- Higher acquisition costs compared to other light sources

HPS-Beleuchtung (Hochdruck-Natriumdampflampen)

Advantages:
- High light intensity, ideal for plant growth
- Widely used and proven in cannabis cultivation
Disadvantages:
- Generates a lot of heat, which can lead to heat stress in plants
- Higher energy consumption compared to LED lamps

Fluorescent tubes (CFL)

Advantages:
- Inexpensive and widely used
- Good light distribution, ideal for germination and the early growth phase
Disadvantages:
- Lower light intensity compared to LED and HPS
- Shorter service life and higher energy consumption

Metal halide (MH) lamps

Advantages:
- High light intensity with a spectrum suitable for the vegetative phase
- Promotes strong and healthy growth
Disadvantages:
- Generates a lot of heat
- Higher energy consumption and shorter service life than LED lamps

Cannabis growth phase: How long does it last?

Duration of the growth phase

The duration of the growth phase for cannabis plants can vary depending on the strain and the cultivation goal. As a rule, the vegetative phase lasts between 3 and 16 weeks. This phase begins after germination, when the seedling grows into a young plant, and ends when the plant enters the flowering phase.

Short vegetative phase (3-5 weeks): Often used for indoor cultivation and autoflowering varieties to achieve a faster harvest.
Middle vegetative phase (6-10 weeks): Often used for normal indoor and outdoor cultivation to ensure balanced growth.
Long vegetative phase (11-16 weeks): Mostly used for outdoor cultivation or special breeding projects to achieve maximum size and yield.

Factors influencing the duration

Several factors can influence the duration of the growth phase. Here are the most important ones:

Genetics of the plant

Sortenunterschiede: Indica strains tend to have a shorter vegetative phase than sativa strains. Autoflowering varieties automatically switch to the flowering phase regardless of the amount of light, which shortens the growth phase.
Hybride: Mixtures of indica and sativa can have different growth phases, depending on the dominance of the respective genetics.

Lichtzyklus

Lichtdauer: The amount of light has a direct influence on growth. An 18/6 light cycle (18 hours of light, 6 hours of darkness) promotes rapid growth. A longer light cycle can prolong the vegetative phase, while a shorter light cycle allows the plant to enter the flowering phase more quickly.
Lichtqualität: High-quality lighting promotes healthy and rapid plant growth. LED lamps with an adjustable spectrum can optimise the growth process.

Nutrients and irrigation

Nährstoffzufuhr: A balanced nutrient supply with a focus on nitrogen promotes leaf growth. An undersupply can slow down growth and prolong the growth phase.
Bewässerung: Even watering is crucial. Over- or under-watering can impair growth and prolong the phase.

Anbaumethode

Indoor vs. outdoor: Indoor cultivation allows better control over the growing conditions and can shorten the growing phase. Outdoor cultivation depends on natural conditions and can therefore vary.
Hydroponics vs. soil: Hydroponic systems generally promote faster growth by optimising the supply of nutrients, which can shorten the growth phase.

Umweltbedingungen

Temperature and humidity: Optimum temperatures (20-28°C) and humidity (40-70%) promote healthy growth. Deviations can slow down growth.
Luftzirkulation: Good air circulation prevents mould and diseases that could impair growth.

Preparation for the flowering phase

Transition from the growth to the flowering phase

The transition from the growth phase to the flowering phase is a critical point in the life cycle of the cannabis plant. This transition is initiated by changes in light cycles and environmental conditions. While the plant is mainly focussed on the growth of leaves and stems in the vegetative phase, energy is concentrated on the production of Flowers (buds) in the flowering phase.

Adjustment of the light cycles

Adjusting the light cycles is the key to initiating the flowering phase. Here are the steps you should follow:

Change of the light cycle: Reduce the light hours from 18 hours of light and 6 hours of darkness to 12 hours of light and 12 hours of darkness. This change simulates the natural conditions that occur in autumn and signals to the plant that it is time to flower.
Lichtintensität: Make sure that the light source is still sufficiently intense to promote flower growth. High-quality LED lamps or HPS lamps are ideal for this phase.
Dunkelheit: Make sure that the dark phase is completely dark. Even the smallest light leaks can disrupt the flowering process and lead to stress in the plants.

Preparing the plants for Flower

In addition to adjusting the light cycles, there are other important measures to optimally prepare the plants for the flowering phase:

Nährstoffumstellung

Phosphorus and potassium: During the flowering phase, cannabis plants need more phosphorus and potassium to support flower formation. Therefore, switch to a flowering fertiliser that is rich in these nutrients.
Reduction of nitrogen: Reduce the amount of nitrogen in the fertiliser, as too much nitrogen can inhibit flower growth and lead to excessive leaf growth.

Pruning and training

Entlaubung: Remove some of the lower leaves and branches to concentrate the plant's energy on the upper inflorescences and improve air circulation.
Low Stress Training (LST): If not already done, light training techniques such as bending the branches can be continued to ensure even light distribution.

Umweltbedingungen

Temperatur: Keep the temperature between 20-26°C during the day and not below 18°C at night. Excessively high temperatures can impair flower growth.
Luftfeuchtigkeit: Reduce the humidity to around 40-50% to minimise the risk of mould forming on the Flowers.
Luftzirkulation: Good air circulation is crucial to prevent mould and disease. Use fans to keep the air moving.

Monitoring and maintenance

Regular inspections: Check your plants regularly for signs of disease or pests. Early detection and treatment can prevent crop losses.
Pouring: Keep the soil evenly moist, but avoid waterlogging. The plants may need a little more water in the flowering phase to support increased growth.

Common mistakes in the cannabis growth phase: watering, fertiliser and more

Overwatering and underwatering

A common problem when growing cannabis plants is incorrect watering. Both overwatering and underwatering can severely impair the growth and health of the plants.

Überwässerung:
- Symptoms: Yellow leaves, limp plants, root rot.
- Ursache: Too frequent watering or poor drainage.
- Lösung: Reduce the amount of water and ensure good drainage. Allow the top layer of soil to dry slightly before the next watering.
Unterwässerung:
- Symptoms: Wilted leaves, slow growth, dry soil.
- Ursache: Too infrequent watering or insufficient amount of water.
- Lösung: Water regularly and ensure that the soil is evenly moist but not wet. Use mulch to retain moisture.

Incorrect nutrient intake

The correct nutrient supply is crucial for the healthy growth of cannabis plants. An incorrect nutrient supply can lead to deficiency symptoms or over-fertilisation.

Nährstoffmangel:
- Symptoms: Yellowing leaves (nitrogen deficiency), red-violet leaf stalks (phosphorus deficiency), yellow leaf tips (potassium or magnesium deficiency).
- Ursache: Insufficient fertilisation or incorrect pH value that hinders nutrient uptake.
- Lösung: Use a balanced fertiliser and make sure the soil pH is correct (6.0-7.0).
Over-fertilisation:
- Symptoms: Dark green, burnt leaf tips, salt deposits on the ground.
- Ursache: Too frequent or too heavy fertiliser application.
- Lösung: Rinse the soil with clear water to remove excess nutrients and reduce the amount of fertiliser.

Temperature and humidity problems

The right temperature and humidity conditions are crucial for the well-being of cannabis plants. Deviations can slow down growth or promote diseases.

Temperaturprobleme:
- Temperatures too high:
  - Symptoms: Burnt leaves, slow growth.
  - Ursache: Insufficient ventilation or too close placement of the light source.
  - Lösung: Reduce the temperature by improving ventilation or increasing the distance to the light source.
- Temperatures too low:
  - Symptoms: Slow growth, dark green or purple leaves.
  - Ursache: Growing room too cool or temperature fluctuations at night.
  - Lösung: Increase the temperature by using additional heat sources or insulating the growing space.
Luftfeuchtigkeitsprobleme:
- Humidity too high:
  - Symptoms: Mould formation, slow growth.
  - Ursache: Insufficient air circulation or excessive humidity in the growing space.
  - Lösung: Reduce the humidity through better ventilation and dehumidifiers. Keep the humidity in the vegetative phase at around 40-70%.
- Humidity too low:
  - Symptoms: Wilted leaves, slow growth.
  - Ursache: Dry air or excessive ventilation.
  - Lösung: Increase the humidity by using humidifiers or water trays in the growing room.

Fazit

The growth phase of cannabis plants is one of the most important stages in the plant's life cycle and lays the foundation for a successful Flower and harvest. With the right care and attention during this phase, growers can ensure that their plants grow healthy and strong.

Important findings:

Germination and seedling phase: Germination is the first step and requires careful conditions to ensure that the seeds sprout successfully and grow into healthy seedlings.
Vegetative phase: During this phase, the plants develop their structure and strength. Optimum light cycles, nutrients and environmental conditions are crucial for healthy growth.
Pruning and training: Techniques such as LST, SCROG, topping and fimming help to control growth and maximise yields.
Light in the growth phase: Sufficient and high-quality lighting is crucial to promote growth and prepare the plants for the flowering phase.
Preparation for Flower: The adjustment of light cycles, nutrient changes and optimal environmental conditions are necessary to ensure a smooth transition to the flowering phase.
Avoiding common errors: Proper watering, adequate nutrient supply and controlled temperature and humidity conditions are essential to avoid problems and promote growth.

By carefully monitoring and adjusting these factors, you can get the best out of your cannabis plants. Each step in the growth phase contributes to the health and productivity of the plants, which ultimately leads to a successful and abundant harvest.

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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.