■ What is a seedling?
A seedling is a young plant developing out of a plant embryo from a seed. Seedling development starts with germination of the seed. A typical young seedling consists of three main parts: the embryonic root, the embryonic shoot, and the seed leaves. The two main classes of flowering plants are distinguished by their numbers of seed leaves: monocots have one blade-shaped leaf, whereas dicots possess two round leaves.
■ From seed to seedling, made easy
Although growing from seed to seedling is a relatively simple process, if not done correctly your seed will fail to germinate. Seeds require a sufficient amount of light, the right temperature, the right oxygen levels and water levels to germinate into seedlings. The seed has its own food stored in it for the first growth. After this, when the first roots and leaves develop, the seedling starts to take its nutrients through the roots and photosynthesis.
As discussed earlier, there are two types of seeding, Monocots and Dicots. Each begin life in different ways.
The Monocot, the first root is enclosed by a coating known as a coleorhiza, this means the root pushes off the seed first, followed by the leaves, also covered in a coating called a coleoptile. This process happens below the surface.
The Dicot, the root is produced first, which then anchors the seeding to the earth, where it starts absorbing water. Once this process is complete, then the first shoot appears. This process happens above the surface and is known as epigeous germination.
■ Seed to seedling process:
Step 1: Water fills the seed. Known as Imbition.
Step 2: The water activates enzymes that begin the plant's growth.
Step 3: The seed grows a root to access water underground.
Step 4: The seed grows shoots that grow towards the sun.
Step 5: The shoots grow leaves and begin photomorphogenesis
Notes. (Photomorphogenesis is a separate process to photosynthesis. Photomorphogenesis is light controlled seedling development where the seedling develops its growth patterns according to the light spectrum it is supplied. Photosynthesis is where the plant uses light as a source of energy).
During Step 1 the seed rapidly takes on water resulting in the seed swelling and softening, as long as the seed is at the optimum temperature for its type. The temperature varies from 13-30°C, so its worth researching the plant before you germinate.
During Step 2 the water absorption activates enzymes that start to change the seeds internal physiology, the seed starts to respire, produce proteins and metabolises the food stored within the seed.
During Step 3 With the swelling and softening of the seed, the coat then easily ruptures when the first root emerges searching for water, this first root is known as the radicle.
During step 4, once the primary first root finds a water source the first plumule (or shoot) starts growing upwards looking for a light source, in the case of some plants you keep them in darkness longer to accelerate this growth stage, such as microgreens.
During stage 5 the cells of the seedling become metabolically active, it elongates and divides, lifting the seedling and producing the first leaf.
■ How can we help you?
From seed to seedling is the start of your plant and an important stage where you need to give your plant the best start in life. At Greenmakers we have Sponge Pot, a radical new organic seed germination pot designed to speed up the germination process, while helping the seedling to become strong and develop quicker than it would in soil. Designed for optimal propagation, its simple to use and leads to explosive first root growth due to the substrate structure and air to moisture ratio. Supplied with our own bacto, a mixture of beneficial soil bacteria and fungi promote a healthy root system from day one. Our unique sponge substrate with added coconut coir means your seed will get the perfect ratio of water to air, and roots can easily develop.