What is plant allelopathy?

Plants are very interesting beings: decorative, useful, with a more or less simple maintenance (depending on the species)… But, in addition, there are some that are allelopathic. What does that mean? Well what produce one or more biochemical compounds that influence the growth, survival or reproduction of other plant beings. It is interesting then to know what is allelopathy, since this way we will know why some plants fail to grow when they are grown under the branches of others.

Allelopathy is a phenomenon whereby there are species that are capable of controlling the expansion of others by expelling, mainly through their leaves, some biochemical compounds (a kind of gas invisible to our eyes), which when in contact with a seed or a plant, can prevent it from continuing to grow (which would be negative allelopathy) or on the contrary can help it to develop (positive allelopathy).

Thus, in the first case, little by little the plant underneath is weakened for no apparent reason, and eventually it will die. For example, this can happen if we plant palm trees near pines for example. In the second case, however, what will happen is that the fruits have a better flavor, which is what happens if, for example, lettuce with spinach is planted in a 4 to 1 ratio.

Allelopathic plants are of great interest to agriculture and gardening. Thus, in the garden we can use a series of plants to protect crops from some pests, such as the lavender essence or romero. But we must be careful with species that come from very dry or very humid climates, such as Ficus, Acacia, the Salix (Sauce), or the Eucalyptus, as its roots, in addition to being invasive, will not allow anything (or practically nothing) to grow near them.