A method of seed pretreatment that involves nicking the protective coat of a seed to allow water to infiltrate the coat and promote faster seed germination.
Scarification in the Forest Garden
It is a frequently used method when dealing with species with hard seed coats. By lightly scraping or scratching the edge of the seed coat, scarification allows for water to penetrate and activate the germination process. A knife can be used for this, but nail clippers are another useful and safer tool for scarification, especially for seeds that are somewhat flat rather than round (like Leucaena).
When scarifying, it is important to avoid the hilum side of the seed as this is where the initial roots (radicle) will first sprout. Damage to this area can prevent a seed from germinating. Scarification is very labor intensive, as each individual seed has to be nicked. For large batches of seed, it might be more realistic to use soaking pretreatment methods. However, if you have the time, scarification tends to provide more uniform results.