To grow or not to grow

Dear PlantHive family,

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My name is Tino Dornbusch, passionate about agriculture and plant biology. I have been studying plant growth – a field commonly denoted as phenomics - for almost 20 years now. I joined the PlantHive family about 2 years ago and would like to share my journey, experiences and lessons learned about urban indoor farming with you.

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Magic herbs

After High School, my life fundamentally changed while travelling through Latin America with my best friends. The cultural and culinary differences between Germans and Latinos were eye opening, leading to my first inter-cultural romantic relationship. One young woman twisted my head and she was a fantastic cook. One herb was almost everywhere: Cilantro - also known as Coriander. I had tried to grow the herb in my garden in Germany in the past, but plants started soon to flower and produce seeds and not leaves. Life went on and a couple of years ago I married an Italian woman and we all know what passion for food they have. We love our Pesto a la Genovese, but again, in Germany no fresh Basil at appropriate quality is available.

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Yes, we can buy fresh microgreens in German Supermarkets, but their taste and quality does not match the “southern” quality criteria. Why? Herbs need to grow under environmental conditions they typically are bred for. Both Basil and Cilantro need warm temperature, close to 12h day light and sufficient light intensity. In Germany, we could grow these herbs outdoor from Mai to September, but the long days lead to the production of flowers and seeds rather than what we want: leaves. In winter we lack light and temperature. Hence we would need an indoor cultivation system and I wanted to share some thoughts with you.

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Light

Light is a crucial factor for plant growth, since it powers the process of photosynthesis. We already mentioned daylength as key factor to trigger flowering in many species. Therefore our indoor farm needs to reproduce the requirements of our production goal. Simplified rule of the thumb is: short days (<12h daylenght) let you produce vegetative biomass (leaves) and long days (>12h daylength) flowers and seeds.

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Most plants we grow for food need an appropriate light intensity to grow best and to develop taste. Light intensity can be expressed as light energy in Watts (W) per square meter (m²). On a clear summer day, the solar radiation is about 1000 W/m², but that is far too much for most plants. My experimental setups – like the PlantHive or the Eco Grower - have around 300-500 W/m² and herbs grow well and develop their precious flavour.

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Light quality - or spectral composition of light - is another topic that is often overseen. If you drive through the Netherlands during a winter night, you will likely see Greenhouses in pinkish light setup. This is because growers use red and blue LEDs for growing plants as these parts of the light spectrum have the highest photosynthetic efficiency, but this light is not natural to our eyes and can disturb us in our homes. In general, full spectrum white LED panels will give you good performance.

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Waste of energy?

We are experiencing a global tensioning around energy supply and rising energy prices. This is certainly an argument against indoor farming in general and growing food at our homes in particular. But we can see things also form another perspective.

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1: We need to clearly say that end of September until early April is the main indoor growing time. The rest of the year you can use local and seasonal fresh food. Have a look at my setup at home. I have a southern exposed window and use a hybrid growing style to combine both approaches. On a sunny winter day – yes they exist in Germany – I lower my artificial LED light and let the sun do the job.

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2: My home office is within arm reach of my little farm. It acts as artificial sun (for example to keep up my mood in winter), as oxygen generator (I do need to ventilate the room less frequently) and as heating (2-3°C warmer than the rest of the flat). Besides having fresh herbs at good quality these are some very good arguments for growing food in your home.

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3: My fresh herbs do not need to be packaged & transported to the supermarket and have a better quality. This saves packaging material, is more sustainable and helps the environment.

My little Farm Setup

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Here is the setup where I am currently learning to enhance my indoor farm expertise: I am using the PlantHive EcoGrower (20W) to grow Basil in peat-rich soil (purchased from the Supermarket). I currently harvest 20g leaves each week to make Pesto al Genovese for my family. My LED panel (130W) produces Cilantro, Arugula and Lettuce for our salads, where I typically get 50-75g per week. In my PlantHive I try to learn more about deep water hydroponics. I compare how Lettuce and Arugula grow in a hydroponic setup vs. to the “conventional” soil-based approach, and realize that I still need to learn a lot about hydroponics to become a real expert. Even though I still have a lot of tests to undergo until I feel confident with my hydroponic skills, I try to see things positively. In the end it is all about enjoying the journey and sharing our learning experiences and results.

‍And at the end, the PlantHive Smart Garden and it’s development is on a very good way of combining all the needs and approaches in one device, to provide the best possible customer and growing experience.