This simple and easy-to-use Rust genetics calculator provides good help for calculating your perfect genetics. For more info about the different genes, see below the calculator.

If you are unfamiliar with how to crossbreed in Rust, check this video out on YouTube by Tamura77. It provides good info on how to do it the right way.

Also, check out our Rust Raid Calculator for planning the perfect raid and the Rust Aim Trainer to get better with weapon spray.

Updated
What you get
Input gene from first plant
Input gene from second plant
Input gene from third plant
Input gene from fourth plant
Input gene from fifth plant
Input gene from sixth plant

Genes

Each plant has 6 slots, and what type of genes a plant has are randomly generated as soon as they are planted. Do note that of all the genes, X and W genes are the bad ones. We don’t like them. If you want to cultivate a different strand of the gene, you will have to grow several plants beside each other in the hope that one of the genes will override the other by crossbreeding.

I strongly recommend planting one seed in each corner of a large planter box to not interfere with other seeds. Then you have the chance to get a good gene.

= Growth
Growth rate meaning how quickly the plant is growing, but this doesn't fully mean the plant is healthy, so make sure to keep a good eye on the other genes to see how they do.

= Increased Yield
This means how much income you get once the plant finishes growing.

= Increased Hardiness
Increased Hardiness is how hard the plant is, but that doesn't matter to you, the more useful information you would want is that the harder the plant is the more you get once eating it, this meaning health and hunger.

= Increased Water Intake
As stated above the Water Intake is one of the bad ones, this meaning if the water intake were to overrun the other genetics it would make the plant overall unhealthy and unbalanced. We don't like this one.

= Null/Empty
Empty gene. Nothing much to say. We don't like this one either.

Source: Facepunch Wiki