The process of germination
Germination starts when we sow the seed in the soil and water it. We should take care that we do not put too much water.
As the seed absorbs water, minerals and oxygen from the soil, it swells and pops open.
First the cotyledons and the radicle comes out. The radicle grows to become the root and takes hold of the soil. It will start to take the water and nutrients from the soil. As it grows the root takes a firm grip of the soil. So the plant can come up above the ground.
Next, the hypocotyl comes out of the seed. The hypocotyl continues to grow upward. Along with hypocotyl the epicotyl also grows upwards.
The hypocotyl and the epicotyls start to appear above the soil and slowly grow to become the stem and leaves of the plant. Then the plant can do photosynthesis and not rely on cotyledons for food. Then the cotyledons become brown and fall to the ground.
This process, from the seed to the new plant is called germination.
Seeds with softer coats germinate faster than the seeds with hard coats.
Seeds with hard seed coats need more time to absorb enough water to soften the seed coat and that the inside parts of the seed can break through.
Seeds only germinate when the conditions are suitable. Otherwise the seeds lay dormant. Dormant seeds are inactive, and no changes will occur till we provide suitable conditions.
What effects germination?
Sunshine: Seeds may not need sunshine, but they must be warm to germinate. Sun heats up the soil, and this warm soil helps the seeds to germinate.
Water: The amount of water in the ground also affects germination. Seeds need water to germinate. If the soil is too dry, the seed will not get enough water. If it is too wet, the soil will not have enough oxygen in it to give it to the seed.
How deep we sow the seeds: If we sow a seed too deep, the seeds have more distance to cover when they try to come out of the ground. The food stored in the seed will be over before they reach the ground. Hence, we should sow the seeds near the top of soil.
Season: Seeds need warmth. So, in winter the seeds cannot germinate as it is cold and sunlight is also less. Seeds wait till spring when it becomes warm again to germinate.
Other ways to grow new plants
Not all plants have seeds. So, how do new plants grow in such plants?
Grafting: Planting the cutting of stems in the ground is called grafting. Strawberries, money plant, etc., grow from stem cuttings.
Plant modifications: When we plant a carrot or potato in the soil they grow into new plants. They also produce more potatoes and carrots.
Spore: Some plants produce spores, which can grow into new plants. Mushroom, ferns etc., grow new plants through their spores.