Different varieties of grass reproduce through various means. Some form runners that spread over the surface of the soil, sending down roots at intervals. Others form large clumps of underground tubers that support new plant growth. Many types of grass plants spread through seed dispersal. Fertilized seeds form on mature plants and drop to the soil to germinate, forming additional plants of grass. Grass seeds contain basic characteristics that play an important part in plant reproduction.
Grass seeds form on mature plants. Depending on the variety of grass, plants can mature and begin producing seeds within a just a few weeks of germination. For the seeds to begin forming, the grass plants first produce small flowers, called florets. Flower parts supply the necessary components for fertilization. Once fertilized, the small seeds begin to form on long spikes, called spikelets.
Grass seeds contain a textured outer coating that encourages seed dispersal. In nature, this coating adheres to the fur of passing wildlife. The animals then transport the seeds to new locations for growth. Commercial bags of seeds seldom contain these outer sheaths due to prior processing. Grass seeds contain other segments, such as the aleurone layer, cotyledons and radicles. These segments all play an important part in germination and early growth. The seed's endosperm provides a source of energy for the embryonic plant, known as the plumule.
Grass seeds require specific temperatures and adequate time to germinate and begin sprouting. These characteristics vary between types of grass plants. Annual grass seeds often require less time to germinate. For instance, annual ryegrass, wheat grass, triticale and sudangrass all begin germinating within a week to 10 days. Some perennial grasses, such as Indiangrass and Bermudagrass, can take more than three weeks to germinate. While the ideal temperatures for germination vary between 60 and 85 degrees Fahrenheit, all grass seeds require warmth to grow. Water also plays a necessary part in softening the outer coating on the seed, providing moisture and encouraging the germination process to begin.