In one sentence, describe what the following article is about:

This is probably the most widely used method by the majority of growers, including many agricultural grain crops. There are many ways to pre-treat seed for attempting germination in the artificial setting of a greenhouse. These are processes used in an effort to overcome seed dormancy and reach successful germination on a human driven schedule. Mother Nature does a wonderful job of overcoming dormancy so seed will germinate at the safest time for the seedlings to emerge into a growth friendly environment. We try to imitate those processes to grow plants indoors successfully. All of these asexual methods develop plants that are essentially clones of the original specimens. Putting slips into a jar of water in the kitchen window until roots form are stem cuttings. This method as a high risk of mold developing.  Dividing clumps of plants, such as Hostas, when they get very large is another form of asexual propagation. Plant bits of a rhizome root will cause new plant growth and is another form of cutting. The practice of grafting which is often used with roses and fruit trees is a type of asexual propagation. Use layering with raspberry canes where they are bent over to the ground and covered with soil where new roots will develop.

Summary:
Use sexual propagation for increasing plant numbers by germinating seed and growing the seedlings to maturity. Use asexual propagation for processes that involve using the leaf, stem, and root cuttings.