Why my weed Leaves Are Drooping When novice growers see that the leaves of their marijuana plants are drooping, they often assume it is a sign of an under-watered plant. A lack of water can certainly be an issue, and also has a variety of consequences, including: . . .
Reducing the rate of photosynthesis in the plant. This slows the rate of growth and development of the plant. Stagnation of nutrient delivery, causing nutritional deficiency. The plant is forced to breathe faster; causing the plant to invest precious energy in breathing, instead of growing.
Lack of water might also cause your leaves to:
Droop Become brighter Shrivel suddenly Begin to wither
While many new marijuana growers are overly enthusiastic and water their plants too often, others go in the opposite direction for fear of overwatering their crop! It is imperative that the roots of your plants have access to moisture 24/7 because they are continually losing water through their leaves in a process known as transpiration. This process is how plants get water up from their roots. When your marijuana plants lose water from their leaves, they begin to pull water up from the ground. Underwatering is mainly an issue when plants are still seedlings. They are drooping, wilting, and clearly not growing correctly. You will also notice that the growing medium is not moist. Another symptom is when the seedling turns a dark green color and is stunted and twisted. Any new growth looks discolored.
Why Your Leaves Are Drooping 1. Over Watering Alright, so one of the main reasons why your weed plant's leaves are drooping is because you are overwatering your plant. Now, a lot of people
might think that pot leaves are drooping due to underwatering, but this is generally not the case. In fact underwatering marijuana plants usually always results in wilted leaves, not drooping leaves. We will discuss the difference between wilting and drooping leaves later on below. The point here is that overwatering your pot plant can cause the roots to take in too much water, therefore causing your plants to suck up too much water. The result here is that your pot plants will have leaves that are way too heavy with water weight, and essentially, your pot plants are drowning in water. It might all start at the roots, but the problem quickly works its way up to the leaves.
2. Humidity Is Too Low Another reason why the leaves of your marijuana plants are drooping may be because the humidity level in the grow tent is too low. You see, when the humidity in the grow room is too low, it will cause the water in the leaves to evaporate at an increased rate, thus the water in the leaves exits through the fibers, and into the air. This is indeed a problem, but it's not the same thing as underwatering your plants. You could be giving your pot plants the right amount of water, but if the humidity level in the grow room is too low, that water won't stay in the plants, but rather evaporate out of the leaves. Now, what you do need to know of course is what the proper humidity level for pot plants is. This really depends on the stage of life which the pot plant is in, but for the vegetative and flowering stages, you usually want a humidity level between 40% and 60%. Anything below that, and the leaves will probably start to droop. So, the easy solution for this problem is to increase the humidity level in the grow room.
3. A Nutrient Deficiency OR Too Many Nutrients Signs Of A Nutrient Deficiency 
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A nitrogen deficiency may result in yellowing leaves, starting at the bottom of the plant and then working its way up, until most of the leaves have yellowed, drooped or curled, and fallen off the plant. Signs of a phosphorus deficiency include wilting leaves, the purpling of leaf stems and older leaves, severe slowed growth, and dark or copper colored spots on the leaves.
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Signs of a potassium deficiency include some wilting leaves, rusty brown leaf tips, the yellowing of older leaves, and other similar symptoms.
Signs Of Too Many Nutrients
Now, if you are giving your weed plants way too many nutrients, it may also result in drooping leaves, although this is rarely the case. If you plants are suffering from nutrient burn, they will probably curl, turn yellow or brown, and look like they
How to Help a Drooping Plant? The main thing to remember is that drooping (or wilting) leaves mean that your plant has a deficiency. Unfortunately, a deficiency can come from several areas. On the plus side, in the vast majority of cases, drooping leaves are a sign of a plant that has been overwatered or underwatered, or else it is a sign that your plant is either getting too many or not enough nutrients (and issues with watering are often linked with nutrient problems). When you choose a growing medium with good drainage, you eliminate many potential crises from the get-go. You can check the moisture content of the growing medium by using your fingers or by checking the weight of the pot. A more accurate method is to invest a few bucks in a soil sensor which takes the guesswork out of things. Watering your plants correctly to avoid drooping leaves begins by getting your timing right. It is best to water first thing in the morning. Saturate your growing medium until you see around 20% of the water dripping out of the bottom of the container. That is enough water for the day. Don't water the plant again until the first inch of the growing medium is dry. If your plants are drooping, let the medium dry out completely, and use a skewer to poke holes around the medium to aerate. Be careful not to damage the roots! Poke around the edges of the medium to about two inches down. You can create small holes by moving the stick in a circular motion. Get another thin stick; this is your support. Place it close to the plant's base and rest it, or else you can tie it to the plant's main stem. Check to see that the branches and main stem of the plant are not weak and thin. If they are, it may be a sign that they are starting to stretch for light. In any case, place your plant directly beneath the light source, and ensure it gets at least 18 hours of light per day. Drooping leaves in the early stages of the growth cycle will probably set you back a few weeks. Wait the extra time to begin flowering, and you can still benefit from a vigorous healthy plant that offers a significant yield.
How to water cannabis properly (for soil and most soilless mediums)
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 water does not come out quickly or pots take more than 5 days to dry out for step 1, you may have a drainage problem) Another simple way to tell if a potted plant is ready to be watered is to pick it up and tell if it feels heavy or not. As plants use up all the water in their pot, it will get lighter. If you need something for comparison, you can get an extra pot and fill it with your growing medium. Now you can use this extra container for comparison with your potted plants as it represents the 'dry weight' of your growing medium. If you pick up a potted plant and its feels just slightly heavier than your dry pot, then you know it's time to water your plant. After a while you get a feel for how heavy your plants need to be and you may not even need the extra pot anymore.