What is a backcross?
A backcross (abbreviated BX) means crossing an offspring plant with one of its parents to reinforce that parent's traits. Breeders use it to lock in a specific characteristic in a strain.
Imagine you have a plant with a flavor you love and you cross it with another to give it a new quality, for example more speed. The offspring carry half the genes from each parent, so part of that flavor can get lost along the way.
If you cross those offspring again with the original plant, you get back more of its genes. It's like adding the main ingredient to a recipe again so it comes through more. That original plant the cross is repeated with is called the recurrent parent.
What BX1, BX2 and BX3 mean
The number shows how many times the backcross has been repeated. The higher it is, the more the plants resemble the original: a BX1 already looks quite a lot like it and a BX3 is almost the same.
What is it used for?
- Preserving a highly prized plant that only exists as a cutting, to get seeds that closely resemble it.
- Adding a new trait to a well-known strain without losing its character. For example, to create the autoflowering version of a classic strain, breeders often turn to several backcrosses with the original variety.
It has a limit: each backcross reduces genetic diversity, and if it's overdone, the plants can lose vigor.
Related terms
Before you grow, check the laws in your country: growing cannabis is not allowed everywhere.
