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pot plant leaves curling down

Over-Watering

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 that is similar to a nitrogen deficiency).

Overwatered cannabis plants are droopy with leaves that curl down. As a result of overwatering, leaves often turn yellow or show other signs of nutrient deficiencies (especially when it comes to younger plants and seedlings!)

Overwatering does not always mean you’ve been giving the plant too much water. It can also mean that you’ve been giving the plant water too often, or growing plants in a growing medium that holds onto water without enough air, or doesn’t have good drainage out the bottom.

Cannabis plants use their roots to get oxygen, almost like they’re breathing. 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, the roots end up sitting in stagnant water. The reason your plants droop is because basically their roots are starving for oxygen.

This sick marijuana seedling has several symptoms including droopiness and leaves with brown spots that appear to be a nutrient deficiency. Surprisingly, the true cause of both problems actually is the thick, wet, muddy soil.

The main sign of a cannabis plant being overwatered are the droopy leaves, though other symptoms often appear around the same time!

Overwatered Marijuana Plants

  • Drooping / Curling is the first sign of overwaterd marijuana plants
  • Plants start drooping soon 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.

The goal is to be watering your plants every 2-3 days. If it needs longer to dry out, you should be giving less water at a time. If it’s drying out too quickly it should get more water at a time (or may need to move to a bigger pot).

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 4-5 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.

This cannabis plant has green healthy leaves, but as a result of overwatering it’s stunted and small even though its more than a month old.

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 as long as your plants are drinking well).

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.

Whenever a seedling has droopy leaves, it means that the roots are either not getting enough water (underwatered) or not getting enough oxygen (overwatered). This seedling has been chronically watered too often, preventing the roots from getting enough oxygen. As a result, the seedling has stayed small and mostly stopped growing.

For your individual growing medium and environment, 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.

Sometimes plants will be droopy no matter what you do, and the true cause is the plant is rootbound and needs a bigger container!

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)

Overwatering and underwatering cannabis plants are easy to do and can cause multiple symptoms including slow growth. Learn to recognize and fix these issues.

Why are Leaves Curling or Clawing? (“The Claw”)

The following symptoms are for when your cannabis leaves are “clawing” or curling up or curling down. Sometimes known as “The Claw”. I’ll give a short explanation with pictures of each problem, plus links to the solutions! Fix this common (but hard to diagnose) marijuana problem today!

Nitrogen Toxicity

A Nitrogen toxicity is the result of the plant getting too much Nitrogen (usually from too high levels of nutrients overall, or by using a Vegetative nutrient in the flowering stage). It causes dark green leaves and curled tips (“the claw”).

One of the main symptoms of a Nitrogen toxicity is curled tips (“the claw”)

A plant with a Nitrogen toxicity tends to be dark green all over

Wind Burn

Caused by too much wind. You’ll notice that the leaves further from the fan don’t have symptoms.

Example of too much wind on your leaves

Bad Soil / Overwatering / Underwatering

You can help prevent over and under-watering your cannabis plants by always starting with good soil or coco coir.

Bad Soil

Bad soil is usually thick and muddy. Plants in poor soil will droop (often with unhappy curly leaves) no matter your watering practices.

Avoid thick soil that stays wet for a long time and doesn’t drain well

Overwatering

Overwatering makes leaves fat with water, and they tend to curl down and droop

Overwatering (especially when combined with heat) can also cause leaves to curl up

This plant was grown in muddy soil, and the curling, unhealthy leaves kept getting worse and worse over time!

Underwatering

Underwatering causes symptoms that often look like overwatering, but you’ll know it’s underwatering if the plants perk up each time after you water them.

Root Problems

Although often caused by overwatering, once the roots are sick you’ll see symptoms for a little while even after you start watering your plants properly.

Unhealthy roots can cause all sorts of problems including curling and clawing!

Unhealthy Roots in Soil/Coco

This plant’s roots were damaged from being overwatered and too hot for several days. As a result, the leaves took on a strange, blistery appearance.

This plant suffered from heat combined with overwatering for several days. This damaged the roots and gave it this odd leaf curling.

Root Rot

Root rot is something marijuana hydroponic growers can suffer from if pathogens attack the roots. It is often triggered by heat and/or lack of bubbles near the roots.

Root rot can cause curling leaves and brown patches as well as sometimes other nutrient deficiencies

Rootbound

If a plant stays in the same container for too long, the roots will eventually start wrapping around the edges of the pot. This is known as being “rootbound” and causes symptoms similar to other root problems.

A rootbound plant has been in the same container for too long. Roots wrap around the edges and “choke” the plant.

Rootbound plants often droop, appear yellow, get nutrient deficiencies, and stay small. Even if you’re caring for them perfectly!

If you see tons of white roots when transplanted, that means the plant was in that container too long

When this happens, the main solution is to transplant the plant into a bigger container. Another solution is to grow in fabric pots or air pots. These types of pots let air in from the sides, killing the circling roots (“air-pruning” them) and prevents the plant from getting rootbound for months.

To help a rootbound plant, transplant to a bigger container with fresh potting mix

Or start with air pots or fabric pots in order to prevent plants from getting rootbound at all

Heat Stress

If plants are experiencing a lot of heat, it can make leaves droop and/or curl. Some strains can handle a lot of heat, while other strains tend to droop when it gets warm.

Heat can cause leaves to curl up

Read more about heat and growing weed:

Light Burn

Plants can get light burn (sort of like a sunburn) even if the temperature is completely under control. The symptoms are usually concentrated close to the grow lights. Sometimes this can cause leaves to claw and curl downwards.

Light burn can cause the leaves closest to the light to turn yellow

Bugs & Pests

Often a bug infestation caused general plant unhappiness, but these are some of the most likely to cause curling or clawing leaves.

Broad Mites

Usually, you can’t see broad mites because they live inside the plant. The main symptom of an infestation is strange leaf curling that is specific to this pest, as well as “wet” looking leaves.

Hemp Russet Mites

Hemp russet mites can also cause drooping and other strange symptoms, but the bugs are so small many growers don’t realize what they’re dealing with.

Hemp russet mites cause drooping and yellow mold-like growth on the tops of plants

A closeup of the hemp russet mites

Fungus Gnats

Fungus gnats look like tiny flies buzzing around your topsoil. Although a few fungus gnats won’t really hurt your plants, a big infestation can damage the roots, causing symptoms similar to other types of root problems.

Learn about the various things that cause cannabis leaf curling or clawing, and get the solutions!