What Things Usually Have to Be Present for Seeds to Germinate?

Water

• When the seed has completed its dormant period and its surroundings tell it that conditions are right for germination, it still cannot grow without water. Throughout the dormant period the seed remains dehydrated. It needs to absorb water to spring to life. The water helps the seed metabolize stored food for energy and grow large enough to break out of its casing.

Oxygen

• The water and the air around a seed are filled with oxygen and need to be in balance for proper germination. Though the seed doesn’t need much oxygen during the dormant stage, it needs lots of it when germination begins. Without enough water the seed can't grow, and with too much, it can't get all the oxygen it needs from the soil, which will also keep it from growing.

Warm Temperatures

• Seeds germinate when temperatures warm up to the level needed for the specific species of plant. A seed won't sprout if the soil temperature is too hot or too cold. Most plant seeds germinate well between 65 and 75 degrees Fahrenheit. This is not the case for every plant, as there are some that prefer slightly cooler or warmer temperatures for germination. Most seeds do not germinate in cold weather, though; warm temperatures, to some degree, are needed for germination to be successful.

Light Levels

• Light levels needed for germination vary from species to species as well. Some plants require a lot of sunlight for the seeds to break out and grow, while other plants may have germination inhibited by too much sun. Some plants actually require darkness for germination. Wildflowers, for example, often need seeds to be planted deeply where no light can get to them, while many vegetables seek sunlight and should be planted shallowly.