Most seeds of plants that
we use as "annuals" or vegetables for the garden produce
seeds that can just be planted, watered and they will
germinate. However, many (but not all) seeds of
perennial plants (both
herbaceous) have built
in mechanisms to prevent them from germinating until
after certain additional needs have been met.
Consider what would
happen if the seed of an oak tree germinated immediately
upon falling to the ground in late summer. The tiny
seedling would just be emerging as the cold of winter
commenced. Most of the time these tender seedlings would
be killed and, thus, limit the continuation of the
In dry, arid regions, the
rains are very inconsistent. So, if all the seeds of a
plant germinated immediately, many years, they would
almost all be wiped out by a severe drought. For the
species to survive, it would help if the seeds of any
year would germinate over several years rather than all
at once. They would have a better chance of hitting the
years when rains come and avoiding putting all their
"eggs" in one basket to be wiped out by a drought.
These natural plant
defense mechanisms fall into the category of seed
dormancy. In nature, plants adapted to a certain
environment have developed ways to better assure the
survival of the species. They are in no hurry and are
willing to wait until dormancy has broken to allow the
seeds to germinate.
Human gardeners tend to
be in more of a hurry. They want their seeds to
germinate all at once and right now. To do this, they
first have to figure out what their particular seeds
need to make them germinate. Resources such as Burpee's
"Success with Seeds", other publications or web sites
can tell you the requirements of any species of plant.
gardeners will need to follow one of two seed treatments
to break dormancy.
- This is a process of exposing seeds to cold,
moist conditions for a period of months after
which, the seeds will germinate.
- Some seeds have very hard seed coats which
require special treatments before water can
penetrate and cause germination to take place.