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 woody and 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 species.

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.

Generally speaking, gardeners will need to follow one of two seed treatments to break dormancy.

  1. Stratification - This is a process of exposing seeds to cold, moist conditions for a period of months after which, the seeds will germinate.
     

  2. Scarification - Some seeds have very hard seed coats which require special treatments before water can penetrate and cause germination to take place.

No Treatment Needed - Many plants, including many perennials, produce seeds which will germinate once the seed is ripe. These may be sown any time after they are harvested or stored until the next growing season.

The following are a few of the genera (but not all) that do not need seed treatments in order to germinate:

Note: We have provided some general information and observations on this topic aimed at the home gardener. Before you take any serious action in your landscape, check with your state's land grant university's Cooperative Extension Service for the most current, appropriate, localized recommendations.

 

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