Maintaining a farm in Israel, often brings the Torah to life. I have learned so much. One example is Kil'ayim.
Before I go on, I want to add this disclaimer. My knowledge is limited to what we have done. In other words, when there is an issue, we will often ask and then learn the halacha (Jewish Law) related to it. If there is a different issue although related, I may not have learned about it. So no one should use what I am about to write without consulting a Rabbi or other person.
To get started, I asked ChatGPT to provide an explanation of kil'ayim co I could add something here.
Kil'ayim does not apply to fruit trees. The concept of Kil'ayim is focused on the mixing of seeds or crops in a field, not plating of fruit trees. However it does impact us when it comes to grafting.
We often graft. Grafting has many benefits. For example, when a tree has returned to its rootstock (such as, an orange tree starts producing a sour lemon-like fruit), we will graft from a healthy tree to encourage growth of tasty oranges.
According to the laws of Kil'ayim, we can graft within the same family. An orange branch can be grafted to a lemon tree, a peach can be grafted to an almond tree but a peach cannot be grafted to a lemon tree.