Things Needed for a Seed to Germinate

Sterile Conditions

• In nature seeds fall onto the ground below the plant, are blown about by the wind, or carried off by animals -- and the conditions they are exposed to are not sterile. In fact, some seeds must be digested by animals in order for them to germinate. Unlike seeds grown in the wild, seeds grown at home need sterile conditions. The reason for this is simple -- some seeds cannot tolerate certain types of fungi and bacteria. Making sure the containers and tools you use are clean, the soil you use is sterile and the seeds are clean is essential to successful seed germination.

Right Light

• Some seeds need light to germinate, other seeds need darkness. Some seeds need a combination of light and dark -- other types of seeds will germinate in either type of lighting. Determining the right amount of light or darkness a seed needs is often challenging. A good chart, such as the one from the North Carolina State University website, along with keeping accurate germination records, will help you determine which seeds need light and which seeds need darkness. Remember to sow seeds on the soil surface if they need light. You can cover them with growing medium once germination occurs, if necessary. Examples of seeds that need light to germinate include lettuce, impatiens, geranium and nicotiana. Examples of seeds that need darkness to germinate are foxglove, larkspur, snapdragon and verbena.

Suitable Temperature

• The soil temperature, not the air temperature, plays a huge role in the germination process. Some seeds germinate better when the soil temperature is 55 degrees Fahrenheit or cooler, other seeds prefer the soil temperature to be closer to 70 or 80 degrees Fahrenheit. Most seeds will germinate when the average temperature range is between 65 and 75 degrees F. Think of the soil as the seeds' blanket and you will understand why the soil temperature matters more than air temperature. This is why so many gardeners use heat mats to germinate seeds. A heat mat keeps the soil warm, which speeds the germination process. The air temperature does not affect the germination process, as long as the soil is warm enough and the seedlings are protected from frost, snow or other weather extremes.

Moisture

• The last thing seeds need to germinate is adequate moisture. Water must penetrate the seed coat, which is often tough, in order for the embryo inside to wake up and know it is time to grow. Soaking seeds in warm water for 24 hours before planting them often helps. If there is no sign of swelling after this time, gently nick the seed coat, making sure not to damage the embryo inside. Think of this like peeling an apple. You want to remove a piece of the outer skin without harming the flesh under the skin. Once the seed begins to swell, it is important to make sure the seed continues to receive enough water to grow. Seeds that dry out at this point die, so keep the growing medium moist – not wet – and make sure the humidity level around the seeds remains as close to 100 percent as possible.