The seedling stage comes after the germination process is successful. This is the most crucial stage of the plants life because they are just starting to build a root system are fairly small and very fragile.
The seedlings won’t need any nutrients at this point. They will use the cotyledons (the embryo leaves) to provide them with the energy to grow a root system and their first set of true leaves. Once they have grown a root system, the nutrients in the soil will be enough to feed it because putting any unnaturally occurring additives at this point could kill them. It is therefore wise to remember that when you water your seedlings to make sure to use plain water that has an ideal P.H of between 6.3 - 6.5 for soil. In case you decide or have no other choice but to use tap water, let it sit in an open container for at least 48 hours to make sure any chlorine and other added chemicals evaporate from the water.
Since the cannabis seedlings have just pushed themselves above ground and shed their protective jackets, they require some light and water to help them grow. These requirements help them to photosynthesize and grow. CFL lights are the best recommendations for seedlings and small vegetating plants because they give off a little heat and can be placed very close to the plant to enable it get optimal lighting without them stretching out towards the light as all plant seedlings in controlled conditions tend to do.
The most important thing you can do for your marijuana seedlings is to provide the basics. To ensure they have moisture, light and warmth. The grow area should not be too hot. A temperature of 35 – 36 degrees Celsius while lights are on is ideal. You can also use a small fan (oscillating fan) set to low to circulate the air and gently blow on the seedlings. They are young and still weak, so it’s imperative to remember that the air being blown ought to be very gentle- just enough to move air around. This primarily prevents over heating but it also strengthens the seedlings and encourages them to grow thicker stalks. As the cannabis seedlings move into the vegetation stage, the speed of the fan can be increased to allow better airflow and give the plants a little more resistance strengthen the plant even more.
The young seedlings require humidity so therefore one should maintain a constant 60-70% at this stage by lightly spraying on the leaves with fresh water daily. It washes the dirt off the leaves while increasing the moisture level. Once steady growth has been established and the roots start trying to grow out of the holes then it is time to transplant and get the plant ready for the vegetation stage and rapid growth.
Whatever type of medium used, growers must make sure it has a neutral pH because too much acidity in it could slow down the growth of the plants and eventually affect the amount of buds to be harvested. For new cannabis growers, commercial potting soil is available for sale which can be readily used for planting. Choosing the right medium for weed growing promotes good aeration, strong root formation, maximum growth potential and great harvest of buds.