Against the backdrop of an unprecedented pandemic, the world now is primarily focused on healthcare and economic issues.  However, there is also one area that is slowly gathering more interest; indoor gardening.

If you are also toying with the idea of starting indoor gardening, either for food security or a wholesome indoor activity, getting to know the basics concepts is important.  Here are 5 essential concepts for you to start with:

1. Differentiating the types of greens

Think of an infant, toddler, child, teenager, and adult. They described different stages in human development. Similarly, you can grow vegetables to different stages based on your timeline and taste preference:

  • Sprouts: 2-5 days old when the seeds have germinated and shoots emerge.
  • Microgreens or vegetable confetti: 1-3 weeks old young seedlings when the first leaves appear. eg. Pea shoots (Dou Miao) and Wheatgrass
  • Baby greens: 2-4 weeks youthful and tender greens. eg. baby spinach or baby Kai Lan.
  • Adult greens: 1-2 months full-sized greens.

For something simple and almost guarantee a bountiful harvest, try sprouting your mung beans, green peas, and buckwheat. A few Youtube videos are more than enough to teach you the tricks. They have 1-2 weeks turnaround besides being lauded for their high nutrition content.  a US Department of Agriculture study shows that microgreens can pack up to 40 times as nutrients as their mature counterparts.

2. Soiled-based and Soilless Culture

We are most familiar with soil-based gardening. The soil has 2 roles:

  • Provide nutrients to the plants through its organic component-dead plant and animal matter
  • Lend physical stability to the plants. This is especially critical for plants with expansive roots or stems such as pepper, cucumber, and potatoes

Unfortunately, soil-borne pests and weeds are an unavoidable nuisance. For this exact reason,  many people shun away from indoor gardening. Soilless culture or hydroponics, in contrast, make use of inert substrate to replace soil. The advantages often cited for hydroponics are:

  • Pest-free, hence no pesticide or contamination to your vegetables
  • Ability to control over the water, oxygen, and nutrients supply with pumps
  • Potentially faster and bigger yield. Roots now have direct access to nutrients,  relieving them from the search

3. Active vs Passive Hydroponics

How the nutrients are delivered to the roots determines if a hydroponics system is an active or passive one. Passive methods consist of Kratky and wicking. From a cost and setup simplicity perspective, they are definitely great for beginners.

There is however a trade-off for passive hydroponics. As plants rely on the partially submerged roots or the wick to access nutrients, uptake is less efficient. Consequently, only small leafy vegetables like spinach and lettuce are suited for such a system.

On the contrary, the water pump in an active system proactively delivers the nutrient solution to the roots. Types of the active system include Deep Water Culture (DWC), Ebb and Flow, Nutrient Film Technique (NFT), Drip, and Aeroponics. These systems are messier. They require installation of air pumps, water pumps, and tubing. At the same time, you need to ensure electricity access and regular maintenance to avoid downtime.

4. Growth Media in Soilless Culture

Growth media are inert materials used to replace the physical support function of soil. By itself, it doesn’t retain or release any substance that can intervene with the plant growth. There are 3 characteristics to look out for in your choice of media:

  • Water retention capability
  • Air porosity: the higher the porosity, the better the root oxygenation
  • Cation exchange capacity: the higher the capacity, the longer the nutritional elements take to be released to the roots

Refer to Growth Media 101 if you would like to have a detailed understanding of the pros and cons of each growth medium. The commonly used media are:

  • Coco Coir
  • Perlite
  • Clay Pellets
  • Vermiculites

5. Plant Nutrition and Supplement

Up until the microgreens stage, the plants are self-sufficient with nutrient reserves in the seed. However, any growth beyond that requires doses of the 13 essential elements.

  • Macroelements: nitrogen (N), phosphorus (P), potassium (K). magnesium (Mg), calcium (Ca), and sulfur (S). Plants need them in large quantities.
  • Microelements or trace elements are iron (Fe), manganese (Mn), zinc (Zn), boron (B), copper (Cu), molybdenum (Mo), and silicon (Si). Plants need them in small quantities.

In terms of application, fertilizers are specific to the growing method. Soil-based fertilizers tend to provide just the macroelements assuming most microelements are present in the soil. Hydroponics fertilizers are formulated to provide all 13 essential elements. Often, they are sold as A and B solutions to prevent chemical reactions between chemicals.

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