How do you recognize a sulfur deficiency in plants?

Sulfur fulfills an important function in plants, just as in the human body. It is not only a building block of a number of proteins and hormones, but also of vitamins, such as vitamin B1. Sulfur occurs in all living things because the amino acids methionine and cysteine are sulfur compounds. This means that most proteins can not exist without sulfur.


Because sulfur is so important, a sulfur deficiency therefore has major consequences for the development of your plants and it is important the grower can recognize a shortage in time.

About sulfur

On earth, sulfur occurs mainly as a compound in minerals such as in pyrite, galena, sphalerite, gypsum and barite. It is a non-metal with a bright yellow color. As an independent element it is odorless, but many organic sulfur compounds smell like rotten eggs. Just think about the fumaroles in Iceland.

When you grow plants in soil, a sulfur deficiency almost never occurs. In areas with volcanic activity there is a relatively large amount of sulfur in the atmosphere, which descends on earth during precipitation. In those regions is never any sulfur deficiency. Also in Western Europe, where there is a lot of industry and car traffic, there is a lot of sulfur in the air because of the emissions, so here too there is almost no shortage in the cultivation in the open ground.

However, this means that if you do not grow in the open soil, you have to keep an eye on whether your plants get enough sulfur.

Functions of sulfur

The element sulfur occurs mainly in the main plant tissues, such as in the seeds and in the cell fluid of the plant. It helps the plant to produce important enzymes and contributes to the formation of plant proteins. In addition, sulfur in the form of sulphate plays an important role in the water management of the plant.

How do you recognize a sulfur deficiency in plants?

A sulfur deficiency can be recognized by a light green discoloration of the leaves. At first the youngest leaves turn lighter in colour, then the oldest leaves. The symptoms of a sulfur deficiency initially look like the symptoms of a nitrogen deficiency, with the oldest leaves becoming lighter green. In the case of a sulfur deficiency, the youngest leaves turn lighter, after which the older leaves become lighter green.

At a later stage, the veins of the leaves and the leaf stalks become purple through the formation of the pigment anthocyanin. The light green colour of the leaves becomes deep yellow. With an extreme and prolonged deficiency, the growth and flowering of the plant also inhibits.

How do you recognize a sulfur deficiency in plants?

As mentioned, a sulfur deficiency will hardly occur when growing in the open ground. However, a sulfur deficiency can occur when cultivating in potting soil, where the pH gets too high (> 6.5) and an also an excessive amount of lime can be a cause of a shortage. The ratio of the nutrients can also cause a sulfur deficiency. For that reason, it is always important to use qualitative plant nutrition.

Plant nutrients for hydroponics contain all substances the plants need, including sulfur, often in high concentrations. To prevent the high concentrations of sulfur and calcium from reacting with each other, resulting in poorly absorbable plaster, both substances are delivered separately in an A-bottle and a B-bottle, such as B'cuzz Hydro Nutrition A and B'cuzz Hydro Nutrition B.

What can you do about a sulfur deficiency?

Preventive you can already do a lot to prevent a deficiency by choosing good plant nutrients containing sulfur.

As with a phosphorus deficiency (phosphate deficiency), sulfur is better absorbed by the plant at a slightly lower pH in the substrate. If there is a high pH in the medium (> 6.5), you can lower it by slightly acidifying the substrate with sulfuric or nitric acid.

If you grow on hydro and there is a sulfur deficiency, then you can best administer sulfur with epsom salt (magnesium sulphate).

Cultivated mushroom manure and manure of animal origin can also be used for the cultivation on soil. The plant absorbs sulfur in the form of sulphate, which is released during the decomposition of organic sulfur compounds. This is a process that takes time and for that reason it is wise to work preventively and to ensure well-digested manure.