[header] How to prune oregano [title] Wait until your plant is at least 4 inches (10 cm) tall. [step] Trimming the plant too early could cause your plant to fail to thrive, so be patient. Luckily, oregano usually grows quickly. 
[substeps] Pruning your oregano will encourage new growth. Not only will it grow more leaves, it'll even grow more stems! [title] Cut back no more than 1/3rd of the plant at a time.