The best way to grow plants from seed varies depending on the type of plant being grown. Most plants are best started indoors with as little root disturbance as possible. Additional requirements, such as seed treatment prior to planting, varies depending on the seeds.
In order to grow from seed, a good planting medium is needed. The best materials to use are light, have good drainage, and are sterile. For example, garden soil, compost, and manure will often cause a seed to rot before it has time to germinate. In addition, most garden soil is heavy and not suitable for starting seeds in containers. Peat, sand, perlite, vermiculite, and coconut husk can be combined to make a good mix for starting seeds in a container.
Using peat pots is one of the easiest ways to grow from seed. Peat pots are made out of biodegradable materials that will break down in the garden. The peat pots are filled with the desired seed starter medium, and the seeds are planted. When the seedlings are ready to be planted out in the garden, the entire peat pot is planted into the hole. As the pot breaks down, the roots grow into the garden soil, which helps avoid root disturbance when transplanting.
Most seeds germinate reliably in a temperature range between 70°F and 85°F (about 21°C to 28°C). Cooler temperatures slow germination rates and often prevent germination of many tropical plants. Higher temperatures can damage seeds and also slow germination rates. Seed packages usually indicate the ideal temperature for the specific seeds.
Growing from seed often requires stratification, or the artificial breaking of the seeds' dormancy. This involves a period of chilling, usually lasting two weeks to several months, followed by planting in warm soil. Many plants from temperate climates will not germinate until chilled for a period of time to imitate seasonal chilling. The best way to stratify seeds is between two layers of damp peat moss in a zip-top bag placed in the refrigerator.
Seeds with hard seed coats must be damaged before they will germinate. The best way to break the seed coat in order to grow from seed is to roll the seed between two pieces of sand paper. The sand paper roughs up the seed surface, allowing water to penetrate and stimulate germination.
Many seeds purchased from seed distributors are already stratified or have broken coats when such treatments are required. When collecting seeds from plants in the landscape, it is best to consider the natural environment. If the climate is tropical, direct seeding should work to grow from seed, while in cold climates, where seeds usually spend a winter on the ground before sprouting in the spring, stratification likely will be necessary.