Semi-hydro / PON culture

Semi-hydroponic (or semi-hydro) growing is becoming increasingly popular. Easy to set up and ideal for many tropical species such as Alocasia , Philodendron , Hoya or Anthurium , this method is based on a soilless system, in which the roots are partially immersed in a nutrient solution. Here's everything you need to know to start (or optimize) semi-hydro growing.

Please note that PON is a Lechuza brand, and for example, at Studio Plantes, other manufacturers are chosen for their reserve pots and for the substrate itself.

Necessary material

- A water reserve pot, if possible with a water level indicator

- Substrate, made of volcanic rocks

- A healthy plant, if possible without emerging leaves during the transition from soil to semi-hydro

- A complete mineral fertilizer (NPK + trace elements).

- Recommended: a pH tester and possibly an EC (electroconductivity) tester.

Why switch to semi-hydro?

- Better aeration of the roots , limits the risk of rot.

- Spaced and more predictable waterings : the water level is easy to monitor.

- Total control of nutrition : each intake is controlled.

- Fewer soil parasites (mold midges and others)

Water and nutrients: pH and EC

The ideal pH

- Target pH: 5.5 to 6.2 (you can generally check the water quality in your municipality online)

- Why? A slightly acidic pH promotes better nutrient absorption.

- To adjust the PH, products exist to raise or lower it (see hydropassion products for example)

EC (electroconductivity) or nutrient concentration

Recommended EC:

- Young or fragile plants: 0.6–1 mS/cm

- Established or very large plants: 1–2 mS/cm

- Excess EC can burn the roots so be careful

- You can measure the EC of your solution using a tester

Choosing fertilizer

- Use a 100% mineral fertilizer, this type of fertilizer is available at Studio Plantes, and can also be used for growing in soil.

- Alternate with watering with clear water every 2 to 4 weeks to avoid salt build-up.

Maintenance frequency

- Monitor the level of nutrient solution (do not exceed 1/3 of the pot).

- Change the solution completely every 2 to 3 waterings.

- Rinse the substrate regularly to avoid limescale deposits or algae.

- Monitor your room temperature to stay above 19 degrees.

The transition to semi-hydro

If you are converting a plant already in soil:

1. Carefully remove the pot, then clean the roots with lukewarm water to remove all traces of organic substrate.

2. Place the plant in the previously rinsed semi-hydro substrate

3. Introduce the nutrient solution gradually.

Tips to avoid mistakes

- Don't flood the system: water should not reach all the roots at first.

- Never use organic fertilizer (risk of rot).

- Be careful with temperatures that are too low: the roots are more sensitive in water.

- Do a test first to see if this growing method suits you, don't start with your most valuable plant

In summary

Semi-hydro is a reliable, clean and precise method for growing indoor plants, provided you:

- Manage nutrition well (pH and EC),

- Choose the right equipment,

- Be patient during the transition phase, it remains stressful for the plant, so favor a transition when the plant is in good shape

- You can get substrates, reserve pots and suitable fertilizers in the accessories section of the site: https://studio-plantes.com/collections/accessoires-terreaux