Indoor gardening is more than just a hobby – it’s an art form! If you want to achieve maximum yields and healthy plants, you need expert knowledge. We spoke to Tom, CEO of Plant Light Science and a seasoned grower with over 10 years of experience in the US and Canada. He shares valuable tips and tricks to help you take your indoor gardening to the next level.
Lighting management: the basis for success
Light is the engine of photosynthesis and is therefore crucial for plant growth. Thomas Mittelstaedt emphasizes the importance of optimal light management: “Many beginners underestimate the importance of the light spectrum.” In addition to the rate of photosynthesis, the prevailing light spectrum also determines photomorphogenesis, i.e. the formation of the plant’s shape, says Tom.
“Changes in the optical spectrum will always result in a photomorphogenesis reaction in the plants,” explains Tom. This has a direct impact on the quality and therefore the sales price of the end product. A classic example of a photomorphogenesis reaction is, for example, the resulting nodal distance of a plant (= leafless section of a shoot axis between two nodes). “For example, in the production of roses, the largest possible nodal distance is desirable, as this correlates linearly with the sales price,” says Tom. For lettuce, herbs and broccoli, on the other hand, customers want the smallest possible nodal distance. Other examples of important photomorphogenesis reactions would be leaf size, leaf coloration, growth height, compactness of the flowers, etc. “Modern LED lamps with an adjustable spectrum offer flexibility here,” emphasizes Tom. The light intensity and spectrum must be adapted to both the respective plant species and the growing conditions. Too little light can lead to plants going yellow, too much light can lead to burns. “A spectrometer or at least a PAR meter helps to determine the optimum light intensity.”
The best LED grow lights in comparison.
Additional tips from Thomas Mittelstaedt:
- Light cycles: “Most plants need a light/dark phase. In the vegetative phase, an 18/6 cycle (18 hours of light, 6 hours of darkness) has proven successful, in the flowering phase a 12/12 cycle.”
- Light distribution: “The light source should be distributed evenly over the plants to avoid shadows. Reflectors help to make optimum use of the light.”
- Distance to the light source: “The distance between the plants and the lamp is crucial. Too close can result in burns, too far and the light intensity is too low. Experimentation and close observation of the plants are important here. Of course, it’s better to measure.”
- Light and stress: “Light stress can damage plants and inhibit growth. Look out for signs such as burnt leaves or discoloration and adjust the light intensity or distance from the lamp accordingly.”
Fault diagnosis: Detect problems at an early stage
Even experienced growers face challenges. Tom gives tips on diagnosing the problem: “Yellow leaves can have many causes: Lack of nutrients, overwatering, pH problems, pests… It is important to look closely and identify other symptoms. Are the tips of the leaves burnt? Are pests visible? The more information you gather, the better you can target the problem.”
Possible problems and solutions:
- Yellowed leaves: “Nutrient deficiency, overwatering, check pH value, adjust fertilizer. Sometimes it also helps to look at the leaf veins: If they remain green while the leaf tissue turns yellow, this could indicate an iron deficiency.”
- Wilted leaves: “Underwatering or overwatering (root rot)? Adjust watering behavior, check drainage. Prick the soil with a finger – if it feels dry, the plants urgently need water.”
- Burnt leaf tips: “Excess nutrients, light too intense, reduce fertilizer, increase distance from lamp. Rinse the soil with clear water (pH 6.0) to remove excess salts from the substrate.”
- Slow growth: “Lack of light, temperature too low, increase light intensity, adjust temperature. Stress factors such as temperature fluctuations or draughts can also inhibit growth.” Check VPD value.
- Pests: “Spider mites, thrips, aphids… Early detection is crucial. Check the plants regularly for pests and intervene immediately in the event of an infestation. Beneficial insects or biological sprays are often the better choice than chemical pesticides and can also be used preventively.”
Yield optimization: getting the most out of it
If you want to achieve high yields, you have to optimize all parameters. Tom shares his strategies: “CO2 fertilization can significantly increase yields. Plants need CO2 for photosynthesis. Enriching the air with CO2 can accelerate growth and increase yields. However, the CO2 concentration should be closely monitored and adjusted to the needs of the plants.” CO2 fertilization only makes sense if a lot of light is used (>1000 ppfd) and the climate and nutrient supply are in the optimum range. CO2 fertilization rarely makes sense in the homegrow sector.
Further tips for optimizing yields from Thomas Mittelstaedt:
- Training: “Techniques such as topping, FIMing or LST (Low Stress Training) can influence plant growth and increase yield. This promotes the development of several main shoots and achieves a bushier plant structure.”
- Crop steering: refers to the targeted control of plant growth by adjusting environmental factors such as water, nutrients and light in order to influence the development of the plant and achieve optimum yields. This is often achieved with the help of technologies such as sensors, data analysis and automation systems.
- Sea of Green (SOG): “With this method, many small plants are grown in a small area to maximize the yield per square metre. SOG is particularly suitable for plants with a short flowering period.”
- Scrog (Screen of Green): “The plants are guided horizontally along a net to achieve even light distribution and optimum use of the area. Scrog is ideal for plants with a longer flowering period and strong growth.”
- Nutrient management: “A balanced nutrient supply is crucial for plant growth and yield. Use high-quality fertilizers and adjust the dosage to the respective growth phase. Also pay attention to the right composition of nutrients – different plants have different needs.”
- pH value: The pH value determines how well plants can absorb nutrients. The ideal value depends on the plant’s stage of development (5.8 – 6.4).
- Genetics: “Choosing the right genetics is an important factor for success. There are varieties that are particularly high-yielding or are well suited to indoor cultivation. Find out about the characteristics of the different varieties in advance and choose the right genetics for your needs and growing conditions.”
Hygiene and cleanliness
A clean grow room is essential for healthy plants. Tom recommends: “Hygiene starts even before cultivation. The grow room should be thoroughly cleaned and disinfected. Tools and pots must also be clean to prevent the introduction of diseases and pests. The grow room should be checked and cleaned regularly during cultivation. Dead plant parts should be removed to prevent mold growth. The humidity should also be in the optimum range to prevent mold.”
Additional hygiene tips:
- Quarantine: “New plants should first be quarantined to ensure that they do not introduce any pests or diseases into the grow room.”
- Hand hygiene: “Wash your hands thoroughly before entering the grow room to avoid spreading germs and diseases.”
- Protective clothing: “Wear protective clothing such as disposable overalls and gloves in the grow room to protect the plants from contamination.”
- Air filter: “An air filter can help to filter dust, spores and other impurities from the air and thus reduce the risk of diseases and pests.”
Conclusion
Indoor gardening is an exciting challenge that requires a lot of knowledge and experience. With Tom’s tips, you can take your indoor gardening to a new level and achieve maximum yields. Don’t forget: continuous learning and exchanging ideas with other growers are the key to success!
From 50€ purchase value
Get a 5€ discount!
Sign up for our newsletter and save on your next purchase!