Soil, coco or hydro: which growing medium to choose?

In short:
For most beginners, quality soil is the best choice because it is easy to use and forgiving of minor mistakes. Coco coir is suitable for gardeners who want more control over feeding and growth. Hydroponics is most interesting for those who want a more precise and controlled growing system.

When we start growing plants at home, we quickly realise that the rules are not entirely the same as outdoor gardening. One of the first decisions is choosing the right substrate or growing method.

The classic and most well-known choice is soil, coco coir is increasingly popular among more experienced gardeners, and hydroponics is often mentioned for more controlled and advanced cultivation.

Each method has its advantages, disadvantages, and specific features. Our choice primarily depends on what we want to grow, how much experience we have, how much time we want to dedicate to plants, and how precisely we want to control growth.

To make an easier decision, it's good to understand how soil, coco coir, and hydroponics differ, what each method allows, and for whom it is most suitable.

Growing in soil

Soil is the most familiar and, for most people, the most natural growing method. It provides support to plants, retains water and nutrients, and offers roots a stable environment for growth.

One of the biggest advantages of soil is that it is beginner-friendly. A quality substrate often already contains some nutrients, so plants don't need intensive fertilisation immediately. Soil also retains moisture and nutrients well, so minor mistakes in watering or fertilising usually do not cause immediate problems.

Soil is a good choice for herbs, seedlings, ornamental plants, lettuce, chilli peppers, strawberries, and many other plants we want to grow at home. It is also suitable for anyone who wants a simpler start without measuring pH and EC values with every watering.

Its disadvantage is that we have less precise control over what is happening in the root zone. If the soil is of poor quality, too compacted, or wet for too long, plants may grow slower, and roots may not get enough air. Overwatering can also lead to fungus gnats, mould, or root rot.
These problems can be reduced by choosing a quality, loose substrate and pots that allow for good drainage. Adding perlite, clay pebbles, or coco coir fibres to the substrate for better aeration also helps.

Soil is therefore the best choice for anyone who wants to start simply, naturally, and with less monitoring.

Growing in coco coir substrate

Growing in coco coir is a kind of intermediate step between soil and hydroponics. The plant still grows in a substrate, but the growing method is more similar to hydroponics.
Coco coir substrate is made from coconut fibres. At first glance, it looks similar to soil, but it behaves quite differently. It is light, airy, and retains moisture well, while also providing more oxygen to the roots.

The biggest difference between soil and coco coir is the nutrients they contain. Coco coir itself has almost no nutrients, so we must fertilise plants regularly and thoughtfully.
This gives us more control with coco coir, but it also requires more attention. Successful growth therefore also depends on what we add to the plant through watering.

If we add too few nutrients, the deficiency quickly becomes apparent. If we add too many, the substrate can be more easily flushed, and the nutrient solution adjusted. 

With coco coir, it is advisable to monitor pH and EC values, as this helps us know if the plant is receiving an appropriate nutrient solution. It is also important that the coco coir is not dry for too long and that there is no salt build-up in the substrate.

Coco coir substrate is popular because it allows for fast growth, good aeration at the roots, and more active control over feeding. It is often used by gardeners who have mastered the basics and want more control than with traditional soil.

It is also a good choice for those who want to take a step up from soil but still want to grow in a substrate that provides support to the plant.

Hydroponics

Hydroponics, or hydroponic cultivation, is a method of growing without traditional soil. Plants receive nutrients from a nutrient solution, i.e., from water in which mineral nutrients are dissolved. Instead of soil, clay pebbles, rockwool, perlite, coco coir, or other material that provides support to the plant can be used.

The main advantage of hydroponics is precise control. We can very accurately determine how many nutrients the plant receives, what the pH is, what the strength of the nutrient solution is, and how often water reaches the roots. With proper use, plants can grow very quickly and more uniformly.

This means that plants in the same system have similar growing conditions, as they receive the same nutrient solution and similar access to water, nutrients, and oxygen. Therefore, they can be more similar in size, colour, and development speed, and the yield is more predictable. In a well-set-up system, it can also be higher than with some other growing methods.

The disadvantage of hydroponics is that soil does not act as a buffer layer that would mitigate mistakes. Too high or too low pH, too strong or too weak nutrient solution, lack of oxygen in the water, impurities, or system shutdown can quickly lead to problems.

You don't have to be an expert for hydroponics, but it's good to understand the basics and monitor the system regularly. If the conditions are right, hydroponics can yield very good results. However, if the system is not well set up, the yield will not necessarily be better than when growing in quality soil.

So what to choose?

If we want a simple start, soil is usually the best choice. It is familiar, easy to use, and forgives beginners more minor mistakes.

If we want more control over feeding and growth, coco coir is a very good next step. It requires more monitoring than soil but allows for faster response and more active growth management.

However, if we want the most controlled growing method and don't mind a little more work, hydroponics is a very interesting choice. It can yield excellent results but requires the most precision.

The best choice therefore depends on our experience, time, space, and the plants we want to grow. For most beginners, it makes the most sense to start with soil and then gradually get to know coco coir and hydroponics.