You are hereOver watering
by Nebula Haze
Problem: After watering, your plants start drooping. Usually the droopy leaves will feel firm and appear curled down (the whole leaf will be curled, not just the tips, which is often a sign of nitrogen toxicity). With overwatered cannabis plants, you may also notice Chlorosis (Leaf Yellowing).
Overwatering does not always mean you've been giving the plant too much water. It often means you've been giving the plant water too often, or growing plants in a growing medium without enough drainage.
Plants use their roots to get oxygen. Oxygen is dissolved in water, and there's also air pockets in their grow medium to provide a source of oxygen. When you water your plants too often, its roots are sitting in stagnant water which no longer has any oxygen left. The reason your plants droop is because basically their roots are starving for oxygen.
Overwatered Marijuana Plants
Drooping / Curling is the first sign of overwaterd marijuana plants
Plants start drooping after watering
Leaves are firm and curled down all the way from the stem to the leaf
Will eventually lead to leaf yellowing and other signs of nutrient problems if not corrected
The drooping cannabis plant below did not have drainage holes (water could not drain out the bottom of the pot). After watering the plant which appeared healthy the night before, the grower came back to this drooping plant the next day - this case of overwatering was caused by too much water being held near the roots due to lack of drainage:
Solution: The best thing you can do for overwatered plants is give them time between waterings, and then start off watering slowly until things seem back to normal. Make sure that water is able to drain easily out the bottom of potted cannabis plants. Be extra careful with small plants in big containers.
How to water cannabis properly
Wait until the top of the growing medium is dry about an inch deep (up to your first knuckle).
Add water until you see some at least 20% extra runoff water drain out the bottom of your pot. Go back to step 1.
If top of growing medium stays wet for a long time, you may need to give your plants less water at a time, or improve your drainage.
Some growers also use the "lift the pot" method to decide when to water your plants (basically wait until your pot feels "light" since the plants have used up all the water). It's up to you to decide what's easier for you.
If your plant medium seems to stay wet for a long time (more than 5 days or so), you may need better drainage. This also can happen when growers put tiny plants in a pot that's way too big.
Make sure that water drains freely from the bottom of your container (it's recommended that you provide enough water to get at least 20% extra runoff every time you water your plants).
You should see water coming out the bottom within a minute or two after watering. Then don't water your plants again until the soil is dry up to your first knuckle.
If your plants are already overwatered, you can try to increase the temperature and airflow to help the water evaporate more quickly. You can also use a pencil to gently poke some air holes into the growing medium to provide extra aeration and oxygen to the roots.
For other growing mediums besides soil, your watering method will vary, but if your plants are drooping and you've been feeding them a lot of water, it's a good idea to cut back and see if that helps.
If you're growing hydroponically with your marijuana roots directly in water and you see the signs of overwatering, that means you have a problem at your roots. Either your plants have root rot which is preventing them from getting oxygen at their roots, or you are not dissolving enough oxygen into the water (you can easily increase the dissolved oxygen in your water with a quality air pump and a few air stones).
Need more help?
If your plant is experiencing "the claw" and not just normal drooping (the ends of leaves are curling like a claw or pointing down like talons), then you may actually have a nitrogen toxicity (too much nitrogen).
These Plants Are NOT Overwaterd, These Leaves Show Signs of "The Claw" which usually indicates a Nitrogen Toxicity
("The Claw", tips bent down, curling / clawing, dark green leaves)