How does scarification differ from stratification?
Written by
Julia Anderson
Reviewed by
Prof. Charles Hartman, Ph.D.Understanding the key differences between scarification and stratification helps avoid errors when gardening. Scarification involves overcoming physical barriers of the seed coat, while stratification addresses internal dormancy mechanisms. These strategies have specific biological functions. Knowing when to use one versus the other greatly enhances the success of germination.
Scarification
- Breaks physical dormancy by damaging seed coats
- Enables water absorption through hard outer layers
- Essential for seeds like morning glories and nasturtiums
Stratification
- Breaks internal physiological dormancy mechanisms
- Mimics winter conditions to trigger germination
- Required for seeds like poppies and fruit trees
Combined Treatment
- Sequential application for seeds with dual dormancy
- Scarify first then stratify for species like milkweed
- Prevents incomplete germination from single treatments
Dissimilarities in methodology are huge. The scarification methods involve physical or thermal damage, such as sandpaper or boiling water. In contrast, the stratification method involves prolonged cold temperatures of approximately 34-40°F, accompanied by moisture. I place damp towels and refrigerate poppy seeds. Scarification takes only hours, while the stratification process may take weeks.
Seeds with dual treatment, such as milkweed, need a specific order. Scarification must be done first, then stratification. The water absorption of the seeds enables the biochemical change that is cold-induced; if this process is reversed, germination will not occur. I doubled the success of my milkweed seeds once I learned the importance of their specific sequence.
#Habitat clues# signal treatment needs. Desert plants typically require scarification. Temperate perennials generally need stratification. Be mindful of the impact on the natural environment. You can trial unfamiliar seeds with a small batch every so often (you may be surprised with what does or doesn't work). Document their germination patterns in a garden journal.
Common confusion results in unsuccessful germination. This occurs when scarification is used instead of stratification for apple seeds, which prevents the seeds from sprouting. Conversely, stratifying morning glories would be a waste of time. Always check the requirements of a seed using the seed packet or a trusted gardening source.
Read the full article: How to Scarify Seeds: A Complete Guide
