A seedling is a young plant or rather that plants growth stage. This growth stage is every naturally grown plants first life cycle and it is also the most fragile and the most dangerous of them all.
In general their life cycle starts when the seed cracks open and ends as soon as the first true leafs appear. Basically a seedling is a plant embryo that sits in a protective layer (the SEED Shell) and start growing when moisture penetrates that protective player. After that initial seed cracking that young plant tries to find sunlight by growing upside down from where the gravity is pulling the seed. This happens because seeds are usually found under ground or under leafs or other material and to get light and in that sense power to grow this plant tries to find its way upward. Seedling at this point grows completely on the power that is stored in the seed because it is not photosynthesizing yet and so there is no energy production. When that little plant reaches trough the ground and finds light the process of leaf opening is started. As soon as those seed-leafs are opened the plant starts photosynthesizing and its true life has started!
How autoflower seedlings differ from other plants?
Autoflower seedlings just like regular cannabis and other plant seedlings have those seed-leafs and cannabis plants differ from other plants like grass and pine species because they have two seed-leafs (dicotyledons). These seed leafs are usually a bit bigger than other specie seed-leafs and if you have seen a lot of plant seedlings you can distinguish cannabis youngsters from other plants. But in general they look like any other seedling and up till the first or second true leafs appear there is little evidence that this young plants is actually from the cannabis genus.
How the growth differs from later growth stages?
Cannabis at this growth stage grows slowly and focuses most of the energy to root growth in order to cover more ground in search for nutrients and also to stabilize itself in the ground. Basically anything that this young plant does is there because it is programmed to survive and that is why you should be careful not to damage this delicate plant. At this start growth stage cannabis plants don’t use almost any nutrients from the surrounding environment and use up all the elements that were present in that seed when it was formed.
because Seedlings use elements from the seed itself you don’t have to give any added nutrients to your growing environment and give them plain water. The watering should be regular but they must not dampen the growing medium too much as too wet (soggy) growing environment increases mold and other bacteria risk but in general you must water more frequent at this stage of growth but also give relatively small amount of water. I like to water my seedling with a hand held humidifier because this allows me to not only water the ground but also moisten that young plant itself and that is convenient because those youngsters need somewhere from 60 to 80 % humidity to flourish!
Cannabis seedlings can grow in almost any light schedule but light schedule as well as intensity and color can affect how fast you seedling develops. I usually keep my seedling under fluorescent lights that run 24/7 as I have found out this increases the growth a bit. In general it is really hard to measure any actual changes in plants if you give them 1 hour less light or keep them in a bit colder than average room only while they are at their seedling phase but thinking about the factors that are involved in that young plants growth we can deduct that:
- Seedling need warm temperature (29 or above C) – This is because cannabis seeds in nature sprout in the spring when the temperatures are warm and the plant can properly photosynthesize.
- Seedling need 24 hour light period – Young plants need as much light as they can get and that will help them develop faster and give you bigger end yield!
- They need very humid environment (60%-80%)– seedling germinate in damp environments and for the first few days they need to retain that wet environment to not dry out and to be able to kick start their life.
- Seedling need no outside nutrients!
- They need 6.5 to 7.5 PH plain water!
Because seedling phase is the first one any errors or environmental troubles can greatly impact the end yield as if you lose just one growth day at the seedling phase you can in fact lose a lot of growth because when the leafs and plant are small they can’t gather a lot of energy and for every energy unit gathered trough photosynthesis that plant grows the same unit of cells!
So when we make some fictional calculations we can see the difference!
Imagine that each cell that can photosynthesize can produce 1 unit of energy and a new cell needs 60 units of energy to develop and all new cells grow at the end of the day and also every minute one cell produces this one unit of energy. In this experiment it means that every hour of light can produce one new cell from one cell.
Let’s start with one cell and two light cycles 24 hours and 12 hours:
- 1. day – 1*24*1 = 24
- 2. day – 24*24*1 = 576
- 3. day – 3456*24*1 = 13824
- 4.day – 13824*24*1 = 331776
- 5.day – 331776*24*1 = 7962624
- 1. day – 1*12*1 = 12
- 2. day – 12*12*1 = 144
- 3. day – 144*12*1 = 1728
- 4.day – 1728*12*1 = 20736
- 5.day – 20736*12*1 = 248832
And at this, my make shift experiment, the difference between the 12 and 24 hour light cycle is significant and the 12 hours cell count is just 0.3 % from the 24 hour cycle cell count!!!
This experiment is in no way scientifically correct but is just a way to show how much better it is for a seedling to get more light and you must provide the best environmental conditions that you can or your total yield can greatly diminish.
A humidity dome is a device that lets you increase the humidity of a particular area of your grow room by enclosing it in see-trough plastic and not letting in any outside air. These domes help with humidity and also temperature control and not many growers use them for seedlings but they should, because, in them you can easily increase or decrease that humidity percentage, and you just have a greater overall control of that grow environment!
In the end I must admit that seedling phase in any plants life is important and it is specially important in cannabis plants because every gram of those end buds is so valuable and it doesn’t matter if you grow short-day cannabis plants or autoflowers, you need to treat them equally!