When and how to water trees?

Trees are plants that usually receive either much more water than they need, or on the contrary less. And the truth is that the issue of irrigation is one of the most complicated to control, especially if the specimens are in the ground, because in these conditions it is almost impossible to know with absolute certainty if the roots are sufficiently hydrated or not.

Therefore, this time I ask you the following question: Do you know when and how to water trees? If you don't know the answer, or if you have doubts, don't worry, I will answer them for you below  .

Not all trees need the same amount of water

And this is the first thing to know. Fortunately, we live on a planet where there is diversity of climates, diversity of soils and habitats, which means that there is a significant number of tree species that live in areas with disparate conditions: some live in areas where the rain is so scarce and the sun is so strong that the land dries up quickly; others, however, have adapted to live in places where the rains are very abundant and the temperature is always warm;... and in between these two extremes, there are many other scenarios or habitats.

For this reason, when we go to buy a tree for the garden or to grow it in a pot, we must find out where it originates from, because the care he has been receiving up to that moment is not always adequate. To give you an idea of ​​what I'm saying, let's talk about Brachychiton populneus, an evergreen tree native to rather dry Australia, and from the Persea americana (avocado), an evergreen tree that lives in central and eastern Mexico and Guatemala.

While the first is very resistant to drought (I have two in the garden and I never water them, and they fall about 350mm a year), the avocado does need to be watered very often, since in its natural habitat it falls between 800 and 2000 mm each year.

So when and how to water trees?

Potted trees

If you grow trees in pots, it really won't be very difficult to control the watering; not in vain, you just have to pour water until you see it come out of the drainage holes, leaving the substrate soaked. In the event that you see that the precious liquid goes to the sides, that is, between what is the substrate and the pot, you should place said pot in a basin with water, since that happens because the earth is so dry it becomes a »block».

The frequency of watering will vary a lot depending on the season you are in, so I always like to advise the same: check the humidity of the soil, for example by weighing the pot once watered and again after a few days. , or with the classic stick, which will come out with a lot of soil attached if it is still wet.

Trees in the garden

If what you have are trees planted in the garden, things get complicated. How do you know when to water them? And how much water do you need to add? Well, it depends on the size of them. And it is that if you have ever read or heard that the surface that its root system occupies more or less coincides with the size of its crown... it is not true, but it is a fact that can help you.

To better understand this topic and avoid problems, you should know that, broadly speaking, there are two types of tree roots: one is the pivoting one, which is the thickest of all and the one that serves as an anchor, and other finer ones that are the so-called secondary roots and that fulfill the function of searching and absorbing water. The pivoting one grows downwards, but it usually stays in the first 60-70cm inland, the others, on the other hand, do grow a lot (a lot, in the case of trees such as Ficus or Fraxinus, which can reach ten meters long or even more).

Thus, when we water we have to pour plenty of water, so that we can get it to all the roots. Generally, if the plants are two metres tall, ten litres may be enough for them; on the other hand, if they are four metres tall or more, ten litres will usually be insufficient for them  .

With all this in mind, we can check the soil moisture with digital moisture meters, which when introduced into the soil will tell us how wet it is, or a method that I personally like more because I find it more reliable is that of dig about four inches next to the plant. It may not seem like much, but if at that depth we see that the earth is very humid, we can get an idea that if we went deeper we would continue to find humid earth, because it is difficult for the sun's rays to reach further down.

In any case, if you have any doubts, do not leave them in the inkwell.