Vernalization in crops

Today we are dealing with a topic in Gardenprue that we will surely have mentioned on more than one occasion, but until now we have not talked about it in depth.

It is about the  vernalization  of the plants, which in this case will be the ones that interest us from the productive point of view. Let’s see a little what this physiological process consists of and what consequences it brings.


You have heard the expression biological clock more than once in human terms.

How our vital biological processes are in a certain way regulated by an internal tic tac that when it jumps it jumps. Although we humans can control or mitigate it with reason, we all know what affects we want to or not.

Plants also, like any living being, also have that biological clock determined among many things by environmental factors (temperatures, hours of light), hormonal and biochemical …

One of these processes well known from the first men who dominated agriculture, is the vernalization or induction to flowering.

A process that affects a large number of plants without which they cannot develop properly. A very clear example that farmers have known for centuries is winter cereals . S

By embracing them at the beginning of spring, a winter cereal remains in a vegetative state all that year. It does not flower and it will be when the action of the low winter temperatures has taken place, therefore it will be the following spring when it will flower.

These processes were known but have been demonstrated and studied not too long ago taking into account the time that man has been dedicating himself to agriculture.

In the middle of the 19th century we have the first reference to this fact.

Since then, the study of the action of cold on crops has been and is, something essential to understand the processes that take place in the plant and thus, control them in the most efficient way possible.


The study of vernalization differs according to the plant with which we are working. There are two distinct groups of plants that determine the complexity of the vernalization process. Monocarpic and polycarpic species.


They are those that bloom when they have met the demands of cold and after setting and fruiting they die. They are species that only last one flowering.

These cases are the simplest because being a single cycle, we can easily establish the necessary parameters for flowering.


Within these, classifications of species that are or are not vernalizable in the seed state could be made.

A very clear example of vernalizable species in the seed stage are winter cereals . The cold hours they need to flower begin to accumulate even in the seed state without having germinated.


They are more complicated. They are species that once germinated, have the characteristic of vivacious and last several years, therefore they have several blooms.

In these cases, not only vernalization can be studied, but everything else that allows the plant to survive several cycles. The clearest example of these species are grasslands, some fruit trees, which, as we know, flourish for years. In these cases there are differences between vernalization and the demands of cold to get out of lethargy. They are two very different things.

Let’s remember:

  • Vernalization is the process by which the reproductive phase of the tree is induced.
  • The cold requirements are the cold hours necessary for the tree to come out of its dormancy or winter dormancy. (It has nothing to do with flowering).

As you can see, many more nuances and considerations about vernalization in different species.

Each genus, each species, each plant is a world. There are more classifications within each group depending on whether vernalization is completely necessary or dispensable.

Other species such as beets for example, are biannual and flowering will not occur until the second year.

As the interest of this crop lies in the roots, worth the redundancy, it does not interest the beet to flower and therefore it is interesting to know the vernalization process to avoid flower induction. Examples of specific species we could put many.


It is very simple.

Vernalization can be measured in the cold hours required by species X to induce flowering.

If the environmental conditions can be moderately controlled, we can calculate to a greater or lesser extent, an approximate flowering date or whether the species will flower or not, depending on whether it has met the necessary cold requirements.

It would not be necessary to wait to see what happens and anticipation in agriculture is one of the most precious aspects.

Finally, it must be clarified that this vernalization process is not mathematically exact (I hope it was) nor is it the only process that influences flowering.

The photoperiod is another factor.

There are also negative factors, such as a severe drought , for example, that can influence that cold temperatures have no effect.

There are many examples, each species is governed by predefined rules in its DNA and the classification we have made is very very general, but we hope it has become clear what vernalization consists of.

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