If you want to grow cannabis outdoors, it makes sense to harden up the seedlings first. It is much easier for marijuana growers to do it indoors. In fact, most states don’t allow outdoor cultivation unless you have a specific license.
It is sensible to gradually introduce seedlings to sunlight by slowly increasing the duration of exposure.
Your primary goals are to keep pests and trespassers at bay and check for infections or infestations. At the end of it all, you are generally rewarded with a bountiful harvest of potent buds.
Use a Small Fan
A cold frame has a glass top where you grow and protect small plants without artificial heat. It is ideal if your goal is to harden up young plants. Again, this is a gradual process. When the seedlings are in the cold frame, put the device in a southwest or south-facing spot (if in the Northern Hemisphere). The design of the cold frame box means your plants are kept at lower temperatures but still enjoy a semblance of protection.
This is a little on the ‘tough love’ side of things, but some gardeners do it! Around a fortnight before the transplant date, stop watering your seedlings. Wait until they show initial signs of wilting. Make sure you pay close attention. If you leave it too long, you could seriously damage your plants. The process shouldn’t take too long because there isn’t much soil in a seedling pot.
As a result, it is necessary to toughen up your marijuana seedlings before bringing them outside. This process is called ‘hardening off.’ You need to complete it gradually to give your seedlings the chance to get used to their strange new environment. In this guide, we offer three different hardening off methods.
Some growers have reported growing seedlings indoors where they had 18 hours of HID or LED lighting a day. They put these healthy seedlings outdoors for a few hours a day in the full sun. To their horror, they found that the seedlings were massively damaged.
For an indoor grower, when a plant is about half the final size you want it to be, you should change it over to the "Flowering" stage. This is the stage when your plant starts growing buds.
Cannbis plants have two life stages:
You do this by changing your light so that it only shines for 12 hours a day, and the other 12 hours a day your marijuana plants are kept in TOTAL darkness.
The first stage, "Vegetative" begins when marijuana plants first sprout, at the beginning of their life.
Photoperiod dependent strains vs. auto-flowering strains