Germination is a process by which an organism emerges from a spore or seed. Seeds germinate when the environment is at the proper temperature, oxygen, and moisture levels. It depends on the variety of the origin. Some seeds can be planted in the soil and immediately begin to grow, while others may require assistance from gardeners to do so on schedule. Find out the requirements for seed germination by researching your specific plant kind.
Types of germination
There are two main types of germination found in plants:
Epigeal Germination: During the epigeal stage, the cotyledons are observed growing above the soil. It results from the hypocotyl’s rapid growth and elongation.
Examples: Bea, castor, gourd, papaya, cotton, and onion.
Hypogeal Germination: Here, the cotyledons are observed to grow below the soil. It happens due to the infant plant’s rapid elongation of the area between the plumule and the cotyledons. The epicotyl is the name given to this area.
Examples: Pea wheat, rice, groundnut maize, and gram.
A unique type of germination known as vivipary or viviparous is seen in mangrove plants. Due to the high salt amount and low oxygen concentration of these plants’ marshy habitat, their seeds cannot germinate in the soil. So, although connected to the parent plant, the embryo develops inside the fruit. As the hypocotyl lengthens, the radical is first pushed out of the seed and then out of the fruit. The parent plant eventually breaks off when the lower portion of the radical thickens and swells, forming new roots and growing into a new plant.
Germination: Parts of seed
Let’s review each part of a seed before discussing how seeds grow into larger organisms and undergo germination. There are four essential components:
The Epicotyl: This is the portion of the seed that develops into the plant’s initial leaves.
The Hypocotyl: This is the plant’s stem.
The Radicle: This is the plant’s first root.
The Cotyledon: This is the seed’s inner protective layer. Its primary function is to store food that the seed can use when germination occurs until it thoroughly penetrates the soil. The seed will have developed leaves by this time, enabling it to obtain nutrition through photosynthesis.
What is seed germination?
Roots, stems, and leaves are the three essential components of the majority of plants that we see around us. Most of them produce flowers once they are fully grown. For example, a mango tree blooms in the spring and bears mango fruit. The fruit’s seed, which we throw away after eating the fruit, we can find inside the fruit. Have you ever seen a new plant emerge from a source you had previously thrown away after eating? The process of a new plant growing from seed is known as seed germination.
Germination factors for seeds
Depending on the plant species, different seeds require different conditions for germination. However, generally, they involve water, temperature, light, and air access. Therefore, to optimise germination, you should understand the particular requirements of the plants you are growing. If you do not have adequate information about the guidelines, either none or only some seeds will start to grow.
Moisture: Water is the first and most significant of all the elements that affect seed germination. Water is necessary for it to happen; else, the seed will remain dormant. However, too much water will cause the seed to decay. Additionally, the soil should be damp but not soggy.
Oxygen: Saturated soil is inadequate because seeds need access to oxygen. For seed germination, the ground needs to be of a medium texture that is neither too packed nor too light.
Temperature: Each seed needs a specific temperature range. In general, germination happens more quickly in warmer climates. Most seeds can germinate in a wide temperature range between 16°C and 24°C. Some sources need soil temperatures between -2°C and -4°C to grow, while others need soil temperatures between 24°C and 32°C, depending on the climate.
Soil depth: Soil depth also varies, depending on the size of the seed. A seed has a certain quantity of energy stored, and it will perish if it exhausts it before the cotyledons reach the soil and have access to light. Therefore, larger seeds require more soil depth to take root.
Light/Darkness: The existence or absence of light is among the most important conditions for seed germination. They are referred to as photoelastic seeds because they germinate in response to light. Tobacco and lettuce seeds, for instance, are positive photoelastic seeds because they require sunlight to grow. However, because they are negatively photoelastic, onion and lily seeds can only sprout in complete darkness.
It is crucial to comprehend seed germination needs for plants to be correctly grown from seed. Therefore, before you begin, be aware of what your seeds require so that a higher proportion of them will germinate and grow into seedlings.
Internal factors
Maturity of embryo: Even though they are shed out of the plant, certain plants still have immature embryos in their seeds. Such seeds don’t germinate until the origin has fully developed.
Viability: Only during the period of viability do seeds begin to sprout. The lifespan of seeds varies from a few days to more than a century. Lotus seeds have been shown to have a maximum viability of 1,000 years.
Dormancy: Seed dormancy refers to a seed’s condition when it cannot germinate despite favourable environmental conditions. During the time of shedding, many plants’ seeds are dormant.
How do seeds germinate?
Beginning with a dormant seed and ending with the development of a young plant, seed germination includes a sequence of events that occur sequentially:
Stage 1: Imbibition: The seed coat swells and softens in this initial stage as it rapidly absorbs water from the surroundings.
Stage 2: Activation: The seed’s built-in enzymes are activated by the absorbed water, starting the embryo’s growth phase. The seed begins respiration by ingesting oxygen and converting the food it has stored into proteins it will need to grow.
Stage 3: Growth: The seed coat ruptures to develop a radical that eventually grows into a primary root when the rate of respiration rises, while the plumule develops into a shoot. Enzymatic activity continues to be at an all-time high at this time.
Stage 4: Morphogenesis (formation of seedling): The first embryonic leaf, or cotyledon, emerges during this seed germination stage. Small foliage leaves, also known as shoot ends, grow over time, and the infant plant continues to consume the nourishment stored in the seed throughout this early growth stage. Once this stage is over, it starts synthesising food through photosynthesis.
How much time does it take for a seed to germinate?
Raising the temperature accelerates germination. In a warm atmosphere, the germination of seeds typically takes one to two weeks. Some sources, such as those for rosemary, chilli peppers, and miniature tomatoes, may even require three weeks. For example, lettuce needs a more relaxed atmosphere because it is sensitive to high temperatures.
6 easy steps for planting your seeds at home
Follow the below-mentioned steps to plant a seed at home:
#Step 1: Check your timing
Making the appropriate timing decisions is the first stage in planting your seeds. First, you must evaluate the weather outside to decide when to plant your seeds. Next, your seeds should be planted so they may be moved out when suitable weather permits. Since this timing varies from seed to seed, it is best to research the ideal growth conditions for your particular sources.
Some of the vegetable seeds you are dealing with are best planted outside. These seeds don’t need to be indoors for very long because they grow and germinate quickly. Some flower seeds are also in this situation.
#Step 2: Find the proper containers
As long as the container has drainage holes and is at least 2-3 inches deep, you can start seeds in nearly any kind of container. Growing seedlings in yoghourt cups, paper cups, and milk cartons might be your thing if you’re the do-it-yourself kind. Some of them favour using seed-starting-specific trays because of their convenience. The watering system maintains constant moisture. The trays are simple to fill and also can be moved with ease.
#Step 3: Get your soil ready
Check that the soil is nicely moist before you plant your seeds. Do not overwater your soil because doing so will suffocate your seeds. Once you have finished, you can add soil to your containers.
#Step 4: Start planting
It would be best to plant seeds at different depths depending on the sources you use. Some tiny seeds don’t even require to be buried very deeply. These seeds need a light dusting of soil on the top to grow. However, larger seeds require deeper soil burying.
You can gently water the pots once you’ve placed your seeds. Your containers can be covered with cling film if you want to maintain the moisture in the soil. Once the seeds turn green, don’t forget to remove this cover.
#Step 5: Water, food, and light
It’s essential to pay attention to your seed’s needs during this growth stage. It will entail regularly fertilising your seeds, watering your soil to keep it moist, and ensuring your seedlings have enough light.
#Step 6: Final Step
Plant seedlings gradually outside. Moving your seedlings from the safe place of your house straight into the garden is not a good idea. These seedlings need slow exposure to the outside after being cared for by you for several weeks. Hardening off is the name of the process.
Place the seedlings outdoors in a sheltered area for a few hours, bringing them inside at night, about a week before you intend to plant them in the garden. Expose them to more and more sunlight and breeze gradually over a week or ten days. Plants can be hardened off in a cold frame.
Quick tips to improve seed germination
Even though seed germination may seem challenging, these techniques will help you make it easier.
- Using seed trays is yet another foolproof method of germination. When sowing each seed or seedling, the soil moisture depth can be better controlled using seed trays.
- Keep a regular eye on the seed environment. If you can feel the soil is dry, water it.
- To maintain the viability of your seeds, store them correctly, ideally in a cold, dry location free from moisture.
- Before putting the seeds in water in a deep container, pre-soak them to hasten the process. Soaking seeds promotes development and aids in water absorption.
- At least 24 hours before sowing the seeds, pre-water the potting soil.
- Monitor how the germination process goes daily and make necessary adjustments to the surroundings.
Even without soil, if moisture, air, and light are present and the temperature is suitable, seeds can begin to grow. In this article, we have stated a complete guide to germination, in which we have discussed what germination is, germination factors for seeds, steps for planting your seeds at home, along with some of the pro tips to improve seed germination. So, you must follow the guidelines to plant seeds at home by yourself.
FAQs
What are the main factors that affect seed germination?
The main factors affecting seed germination are: Soil temperature Growing conditions Timing of planting Daylength
Why do roots grow first during germination?
To improve the water intake, the radicle develops from the seed first. Then, the root apical meristem produces a root cap to protect it.
What happens after germination?
The new plant will gradually start to appear once germination has taken place. First, the plant's root, which holds it to the soil, extends downward. It also allows the plant to absorb nutrients and water needed for growth. Then, as it reaches for the light, the sprout grows upward.
What is the life cycle of a seed?
There are four stages in the life cycle of a plant: seed, shoot, young plant, and adult plant. A little sprout will first appear when the seed is inserted into soil that has gotten water and sunlight.
What is a reasonable germination rate?
A germination test doesn't have to be 100 per cent successful. Anything above a 50% success rate for seeds is acceptable. If germination rates fall below 50%, it might be appropriate to replace the seeds.
