EC for plants: Understanding and controlling this key factor for optimal growth

Introduction

Plant care is not limited to watering or lighting. One of the keys to their health lies in the quality of the water and nutrients you offer them, in quantity and quality (NPK, and other elements). After discussing the importance of pH , today, let's dive into an essential but often overlooked subject: EC .

1. What is EC?

EC stands for electrical conductivity . It measures the ability of a solution to conduct electricity, and is directly related to the concentration of dissolved salts, such as nutrients in irrigation water.

A high EC indicates a high concentration of nutrients in the solution. The risk of too high a concentration could be root burn. Conversely, a low EC means that few nutrients are present in the solution which could lead to a deficiency. As you might have guessed, plants have specific EC requirements to avoid deficiencies or burns.

2. What are the normal EC values?

It is difficult to provide a single answer to this question, because plants have different EC requirements depending in particular on their growth period. For example, annual plants will have very high EC requirements (i.e. quantity of nutrients) because they have extremely rapid growth over a short period. Conversely, plants that will live for several years, such as our beloved Anthurium, have slower growth and their EC requirements will be lower.
Since, to our knowledge, there are no scientific articles specific to the aroids we grow, we offer an empirical deduction regarding normal EC values ​​for aroids.

To begin this deduction we relied on a table of recommended EC levels .

Recommended EC levels, Alchimia.

What we can see here is that the recommended EC level is lower for young plants (1-3 weeks old) than for older plants (eg, 5-6 weeks old). In the blog from which the table and these recommendations are taken, the plant of interest was an annual plant.

We can therefore assume that basing ourselves on the low values ​​in this table would be a good basis.

So we can suggest as normal values ​​for our indoor plants:

  • young plants (seedlings): 0.4 to 0.8 mS/cm
  • 'adolescent' plants : 0.8 to 1.0 mS/cm
  • adult plants that can flower : 1.0 to 1.2 mS/cm

These values ​​are general benchmarks, to be adjusted according to species and growth cycles.

3. How to measure and control EC?

  • Measure : Use a digital EC tester. Simply dip the probe into the irrigation water and wait for the displayed value to stabilize. For example, we use this one .
  • Check :
    • To reduce the EC , dilute your solution with (demineralized) water.
    • To increase EC add fertilizers or additives.
    • Remember to add water and/or fertilizer gradually and mix the solution well when measuring the EC.

4. Why is EC so important?

As we said in the introduction, a poorly adjusted EC can:

  1. If the EC is too low it can: stunt plant growth, cause deficiencies, and limit the number of leaves your plant can maintain.
  2. .

By controlling EC , you ensure an optimal supply of nutrients, essential for vigorous growth .

5. Additional advice and information

As you know, EC is not the only variable to control, pH is also. We recommend adding and controlling the products in your watering solution in this order:

  1. Add your fertilizers to the water first
  2. Measure and control your EC
  3. Finally, measure and adjust your pH

It is worth remembering that fertilizer, by itself, does not trigger the growth of a plant. Rather, its role is to meet the specific needs of the plant when it is in the growth or flowering phase. First of all, ensure optimal growing conditions, such as adequate light , suitable temperature and a favorable environment . Once you observe signs of active growth , you can start adding fertilizer. On the other hand, if the plant enters a dormant period, adjust the fertilization accordingly to avoid excess.

Conclusion

Mastering EC means understanding your plants’ needs to provide them with an optimal environment. A small investment in an EC tester can go a long way! Remember to test your water regularly and adjust your practices accordingly.

This article was co-created with Charlotte Clément, from the Instagram account cha.clement .

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