Recognize and understand plant deficiencies

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This article aims to help you ask the right questions and make the right decisions when you notice that a plant is “tired”. The chemical and detailed understanding of what is happening is not the subject of this article, it is frankly too complicated – but if that tells you, a link at the bottom of the article will tell you more.

What is a deficiency?

deficiency is related to the deficit of an element necessary for the good health of a living organism . In plants it is often linked to a deficit – which may be temporary or permanent – of this element in the soil, or to its use to form other uses. This is the case of soils heavily loaded with limestone, which blocks the iron.
Too often we try to respond to deficiencies with mineral fertilizers – “Your soil has a sulfur deficiency my friend? I have sulfur powder. ” As if we applied a recipe ; “A pinch of copper, three spoons of limestone, a finger of potash, mix it all with the plow, and sow! It is unfortunately a bit more complicated than that …
Note: Deficiencies are also followed closely by practitioners of gardening in pots , where the soil does not regenerate itself.

Recognize deficiencies according to the state of the leaves.

We are nice, we made you a drawing! Keep in mind that these signs may vary from one plant to another , but at least these signs may allow you to rule out parasitosis.

A little drawing is better than long speech! You can click on the image to see it bigger (see the share, it is obviously allowed).

And now, you know everything!

But no, I’m kidding, in fact that’s where it gets complicated. Why ? Because the question is not so much to know what is missing as to know why it is missing … And here the suppositions are numerous.

The 3 causes to suspect in case of proven deficiency.

1. My plant is in unsuitable soil.

This is clearly the most serious case: we still plant too rarely depending on what we can grow in its soil, without taking into account the qualities of the soil , thinking that the plant will adapt to our needs …
Example: you have planted an acid soil plant in calcareous soil , you see traces of chlorosis appear more or less long term. If you had not read this article you would think “it’s a nitrogen deficiency, hop, I’m balancing nettle manure.” In fact, it would have been better to plant something else here.

You are told: the floor is not a supermarket shelf where the minerals are stored on their shelves and where the plants come to shop. In the soil, the elements combine and separate by chemical reaction, so each external input can upset the balance.

The most common case is that of limestone : its excess in the solute state will block the ferrous ions . In clay soil, rich in humus, and in good health, it does not pose a problem because the calcareous ions are fixed to the complex formed by clay and humus and leave the iron quiet. When the humus runs out because we have deprived the soil of its natural contributions in vegetable waste , the clay-humic complex disappears, the limestone is found released and the chlorosis begin. It’s an iron deficiency? No, it’s a deficit in humus that causes iron deficiency 😉

So, if you are in this case, either you have a better location and you move, or you do not have one and you offer the plant to someone who benefits 😉

2. It is a deficiency that happens gradually because my soil “tires”.

Sometimes the soil can not release the nutrients at the rate the plant consumes them . Some plants are super greedy, but sometimes the soil can be damaged and the elements poorly distributed, or the soil reaches the end of its reserves because it has not been fed for a long time.
In principle, if you want to cultivate years the same thing in the same place, everything that is exported must be returned .
Two philosophies exist:

  • or we give back the mineral elements coming from the chemical sector , dosed precisely according to the culture – this is the case of fertilizers for indoor plants, rose fertilizers, fertilizers, orchids, etc.
  • it is regularly fed organic materials , which provide the same elements but less precisely. In nature it works like this, and if the contributions make change the nature of the soil it is not a problem, it is simply new plants that will absorb the surplus. In the garden, it is more annoying because we want to continue to grow zucchini, and not be forced to replace them with rutabaga.

Even if your annuals are in good health, crop rotations and regular soil feeding should be respected . Once the deficiency is detected, it is usually too late. Thanks to keifer.miller for the image!

3. The answer 3.

In fact there are only two causes to suspect!

Short term remedies.

For a quick effect, use composting manure, it is supposed to contain everything you need – unless you compost a very small variety of organic waste! Go slowly, dilute to 1/20 ° and never water on dry ground, you risk burning everything.
Then there are the remedies of grandmother:

  • The banana skins for potassium.
  • The coffee grounds for nitrogen and phosphate.
  • The slate for aluminum sulphate.
  • For iron deficiency, it is better to move the plant to a less calcareous place.
  • But above all, nettle manure for nitrogen and potassium.
  • And even better (in our opinion), human urine! To learn more, this article:  the pee in the watering can , which is full of good things!

In summary.

If a plant has a deficiency, either it is in unsuitable soil , or the soil was adapted initially and begins to “grow poor” . In fact, the first thing to do when you notice a deficiency is to check – for example in the Groww sheet – if you have planted in the right type of soil. Then, modifying a soil by amendments – sulfur, iron, limestone – is not very effective: this kind of process is very long if we want to do it properly – the soil fauna takes a long time to adapt – and n is only possible for professionals. Better to work with what you have and take care of it!

Good crop rotation!

Dr. Monika Mathur

Ph.D Yale University

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