High Pressure Sodium (HPS) – MH and HPS usually go together. Most ballasts that can take MH bulbs can take HPS bulbs of the same wattage. HPS bulbs produce great yields in the flowering stage, but plants in the vegetative stage grow tall and stretched under HPS no matter how close the bulb is kept. If you have an MH/HPS ballast, get an MH bulb for the seedling/vegetative stage so you produce wide plants with close node spacing. Then swap to the HPS bulb after you’ve initiated the flowering stage. Note: HPS produces comparable heat to MH, which means above the 400W size they almost always need to be vented to control heat. However, the smaller MH/HPS sizes such as 150W and 250W run much cooler.
You may only need to give just a little water at a time when plants are small and not drinking much yet.
Temperature – Cannabis seedlings and young plants love when it’s warm but not hot. Plants typically grow the fastest if the temperature stays around 73F at night and 79F during lights-on. Under LEDs, keep it just a bit warmer, 74F at night and 80F during lights-on. Plants can definitely grow well when it’s a bit warmer or cooler, but you tend to get the fastest growth in that temperature range.
In hydroponic growing, oxygen is provided to roots through bubbles. That’s why hydroponic plants don’t get droopy even though their roots live directly in water.
Check out our Plant Doctor tool for help diagnosing sick plants. We also have a friendly growing community where you can post pictures of your plants and ask questions.
As long as you react quickly, you can solve almost any problem without growth slowing down much, if at all.
These plants were grown under a 315 LEC grow light
6.) Genetics & Natural Variation
But isn’t water good for the plant? The problem is that roots also need oxygen, which they typically get through air pockets in the soil. If the soil gets waterlogged from too much water without any pockets of air, the roots start “drowning” from lack of oxygen. The lack of oxygen is what causes the symptoms of drooping and slow growth.
Unfortunately, you can “over-love” your plants. Overwatering is so common among new growers because they are trying to give something good to their plants and get a little carried away.
It can take anywhere from 4 to 8 months to grow a cannabis plant, this varies based on where you’re growing. If you have an indoor grow room, your plant has the ability to flower after only a few weeks!
2. Seedling Stage
Cannabis Growth Timeline
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