Problem: If your plant is drooping, then it’s usually a sign of either over or under-watering.
Cannabis Underwatering Symptoms
- drooping (plants often get better after being watered)
- leaves often seem “papery” and thin because they don’t have any water inside them. (This is opposed to overwatering where the leaves often feel bloated and “fat” from all the water contained inside)
- chronic underwatering eventually leads to yellowing leaves and nutrient deficiencies
If your soil or soilless medium looks bone dry every time you water, or if you know that your roots have dried out, than skip right down the the solution section, as you definitely have a case of underwatering.
Under-Watered Cannabis Seedlings – Leaves feel papery and thin, growing medium is dry
If it gets worse….
The marijuana plant in the middle is under-watered, causing it to droop. Because it was taller and directly under the grow light, it became underwatered even though it was getting the same amount of water as its siblings. Sometimes you’ll see signs of under-watering immediately after upgrading your grow lights (if you don’t change your watering habits), because all the plants start drinking more due to the extra light and heat.
Chronic Under-Watering (Under-Watering on a Regular Basis)
Most growers tend to give too much – not too little – water to their plants. However, if you’re spending long periods away from your marijuana plants or the containers are drying up in less than a day or two, it may mean that your plant needs to be watered more often, or be given more water at a time.
It’s also common to under-water when plants start overgrowing their pots, or if growers get on a schedule of giving a specific amount of water as opposed to paying attention to the soil.
- plant may need to be watered more often
- plant may need more water at a time
- plant may have overgrown its pot and need to be transplanted
It can be difficult to diagnose chronic underwatering because problems may look like nutrient deficiencies. One big clue is that plants perk up every time after you water.
Chronically Under Watered Seedlings – These yellow leaves are actually caused by the plants being slightly under-watered on a regular basis
The curling/clawing and burnt tips on the following two plants may look like it could be caused by another problem, but in this case the symptoms are the result of the plant being regularly under-watered
Notice how the leaves are clawing and tips appear burnt alomost like nutrient burn. It’s happening because the plant isn’t getting enough water on a regular basis.
The leaves near the buds of this male cannabis plant started turning yellow. In this case, the grower determined it was because the plant had overgrown its pot and was drinking more than expected, and as a result the soil was getting too dry between waterings.
More examples of under-watered cannabis plants
Extreme underwatering on a big plant
Not Sure? If you’re not sure whether your plant needs more or less water, how do you figure out exactly why your plant is drooping?
1.) Determine: Is my plant over-watered?
A cannabis plant does not get over-watered because it’s given too much water at once – overwatering is caused by the plant being watered too often, or if the plant does not have proper drainage (which means the growing medium is taking too long to dry out).
2.) If not over-watered, does my plant have root problems?
Growing hydroponically? When you see signs of wilting and overwatering in a plant that is growing hydroponically with the roots in water, usually that’s a sign of a root problem like root rot.
In fact, all cannabis plants can sometimes display wilting/drooping symptoms that are actually the result of root problems.
3.) You may be seeing symptoms of under-watering
So if you read the short description in step 1 about what causes overwatering (and you’re sure you haven’t overwatered your cannabis plants), and you’re certain you’re not seeing signs of root problems, than your cannabis plant might be drooping or wilting because it needs more water.
If you’ve been underwatering your plant, its leaves will look limp and lifeless, like these plants.
Symptoms of underwatering look the same whether your cannabis plant is growing in soil or a soilless growing medium like coco coir or perlite.
Don’t wait until leaves droop to water your potted cannabis plant! While it is generally a good idea to let your potted cannabis plant dry out a bit after watering (watering too often causes its own problems), you should always water your cannabis plants again before the leaves start drooping.
This is the case for cannabis plants grown in both soilless growing mediums and soil.
First-time growers tend to overwater their plants, but underwatering happens too.
So you’re pretty sure your plant is under-watered. A thirsty cannabis plant will usually perk up quickly after the roots are given water.
Learn about ones of the best ways to properly water your potted cannabis plant every time…
How to water cannabis properly (for soil and most soilless mediums)
Wait Until Plant Needs Water – Wait until the top of the growing medium is dry about a half inch deep (up to your first knuckle). Preventing the topsoil from staying wet for long periods of time can also help prevent bugs like fungus gnats. Some growers prefer the “lift the pot” method to figure out when plants want water, where they actually lift the plant to see if it feels light from lack of water. Some non-soil growers, especially in coco or a very high-drainage growing medium, may water a little earlier when the top is just starting to dry out because it’s more difficult to overwater plants in that type of environment. If you continue running into problems with underwatering, you might consider watering more often than is generally recommended. It may be you need extra watering due to small pot size, rootbound plants, temperature, humidity, etc.
Water until you get a little runoff. If using nutrients in the water, add water until you see 10-20% extra runoff water drain out the bottom of your pot. This helps prevent nutrient buildup in the soil and if you have good drainage this type of watering schedule causes plants to grow faster than if you don’t water to runoff (it also makes it much harder to under-water your plants). If not using added nutrients (plants getting all nutrients from the soil, for example in a super soil setup), then only water until you get just a tiny bit of runoff out the bottom, so you’re not washing out your nutrients. However, you still want to make sure you’re saturating your medium – you don’t want dry spots in the soil!
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 or need to give less water at a time until your plant is drinking more. If pots are drying out in just 1-2 days, you may need to give more water at a time, or transplant to a bigger pot.
A 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.
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 Over or Underwaterd, These Leaves Show Signs of
(“The Claw”, tips bent down, curling / clawing, dark green leaves)
From wilting to dropping to yellow leaves to nutrient deficiencies, under watering cannabis can cause a lot of unexpected problems and symptoms. Learn & fix!
Overwatering vs Underwatering Marijuana: How can I tell if my droopy cannabis plant is over or under-watered?
A common question for new cannabis growers is how to tell if your drooping cannabis seedling is over or under-watered. It’s common for new growers to overwater their weed, but that doesn’t mean that underwatering doesn’t happen too. Never fear, once you get a feel for it, it’s easy to tell how often you should be feeding your plant and what is the true cause of your drooping.
If your marijuana shows signs of drooping in normal temperatures, it almost always means you’re over or under-watering your plants, either by watering too often, or by giving too much water at a time when the plant is too young to drink it all.
How often should I be watering my cannabis plants?
Water your marijuana when the top of the growing medium starts feeling dry up to your first knuckle. You should stick your finger 1-2″ into the soil. Wait if it’s damp, but water your plant once it feels dry.
- Soil dries in 1 day or less? Give More Water at a Time (if that doesn’t work, you may need to transplant to a bigger pot)
- Soil takes more than 3 days to dry? Give Less Water at a Time
An over watered cannabis plant will have leaves that are full of water, so the leaves will be firm to the touch and generally curling down (even from the stem of the leaf) almost as if it has too much water weight to hold the leaf out straight.
An under watered cannabis plant will have leaves that are brittle, limp, and lifeless. They will need to be watered every day just to keep them wet. The leaves will seem to be drooping but won’t appear as rounded and full as an over watered cannabis plant.
Leaves feel papery and thin on an underwatered plant, growing medium is dry
If it gets worse….
Now that you’ve (hopefully) got an idea about whether it’s over watering or underwatering, what’s the cure?
Or continue reading….
Over-Watering vs Under-Watering Remedies
Symptoms: seedling is droopy, growing medium is moist, damping off
Most common causes:
When a cannabis plant is “overwatered” it has less to do with the water and more to do with oxygen. Plants can even grow directly in water (hydroponics) but in order to thrive, roots need oxygen. In hydroponics, that’s accomplished by dissolving oxygen into the water. But when plants are grown in a container, too much water = not enough oxygen.
When a plant’s roots are sitting in water, they quickly use up all the oxygen until the growing medium starts to dry out. Without enough oxygen at the roots, the plant will start showing symptoms of oxygen deprivation. Luckily, there are many steps you can take to prevent overwatering your cannabis plants.
While overwatering can display many different symptoms, most overwatered cannabis plants look droopy, like this…
Despite what seems like an obvious cause, several different scenraios can end in overwatering. Here are some of the most common trouble-makers:
Big Pot, Small Seedling
When you have a small plant in a very big pot, it’s easy to overwater because the roots aren’t drinking much yet, and the big container takes a long time to dry out.
Notice how the plants in smaller containers have grown more than the plant that was put in a big container as a seedling. It’s common for plants in too-big containers to grow a little slowly at first.
- (Recommended) Start seedlings in smaller container until they’re growing vigorously, then transfer to a larger container
- If seedling is already in a big container, there’s still hope! When watering, give just a little water at a time in a small circle around the seedling. Then allow the top inch of your medium to mostly dry before watering again. Once the plant is growing vigorously, start watering as normal (with extra runoff water coming out the bottom every time)
These small cannabis plants (below) were put in big pots, and were given enough water to support a much larger plant. The plants couldn’t drink all the water that was given to them and as a result, their roots weren’t able to get the oxygen they needed and started “drowning.” Once the roots are out of commission, the leaves start drooping.
One way to prevent this from happening is to make sure your plants are in an appropriately sized container for each stage of their life; this is done with transplanting.
First, you need to get a general idea of the final container size which will be based on how big you want your plants to grow. The less often you transplant, the bigger the final size pot you’ll need because the roots will tend to grow out and cover the whole container if left too long. You can help avoid problems with roots getting rootbound by using a fabric pot (also known as a “Smart Pot”) or an air pot.
Final Container for Desired Plant Size – General guide
(the less often you transplant your plants, the bigger final size you’ll need)
2-3 gallon container
3-5 gallon container
5-7 gallon container
6-10 gallon container
8-10+ gallon container
But what size pot should you use for your seedlings?
For fastest growth rates, it’s better to plant young seedlings or clones in a very small container, like a disposable plastic solo cup.
For new seedlings and clones, use a small container if possible
Easy transplant guide – some popular transplant guideline:
- Solo cup -> 1 gal -> 3 gal
- Solo cup -> 1 gal -> 5 gal
- Solo cup -> 2 gal -> 5 gal
- Solo cup -> 1.5 gal -> 3 gal -> 5+ gal
There is no perfect transplant guide, but the one above should give you a general idea of where to start.
Why don’t you want to go from a solo cup to a 5 gallon pot? Or why not just start in a 5 gallon pot?
Young plants won’t be growing very fast yet, so they also won’t be using much water. When you completely saturate a big container that slow speed means that the plant won’t be able to drink all the water. Since so much of the water is contained in the middle without access to air, it won’t be able to dry out by evaporation. This means you’re left with a huge container full of wet potting mix.
The young cannabis plant roots will quickly use up all the available oxygen that’s been dissolved in the water, and then the roots will sit in water until the water slowly evaporates on its own. Some containers such as smart pots and air pots allow air in from the sides, which can help dry the growing medium faster, but it’s better to use proper technique from the beginning.
Planting in too big a container is sometimes called “overpotting.” It’s possible to get around this with special watering techniques (for example by giving plants just a little bit of water until they start “growing into” their containers) but starting plants in small containers and transplanting as needed can be a more straightforward way for some growers. Overpotting plants is also a waste of growing medium and nutrients, especially if the plants never get big enough to fully use their containers.
This OG Tahoe Kush seedling was overpotted, though this can be overcome by the grower just giving a little bit of water at a time until the plant starts growing vigorously. At that point, the grower can provide more and more water until they’re finally watering normally.
More information about container size and transplanting here: https://www.growweedeasy.com/germinate#what-size-pot
Small Pot, Big Seedling
While using a too-large container can cause problems for seedlings, so can too-small of a container.
Seedlings are happy in a small container like a solo cup for a while, but as they get bigger, their roots need more room. The roots tend to wrap around the outsides of the container, encasing the middle part so that water can’t get out. This is known as the plant being “root bound.”
If the seedling isn’t transferred to a bigger container in time, it can cause symptoms of overwatering, nutrient deficiencies, wilting, and sometimes very strange and unpredictable symptoms.
These plants were left in a too-small container for too long. Because they were drinking so fast, the grower watered them frequently – too frequently! This combination of being root bound and overwatering caused the plants to suffer.
A too small container, combined with overwatering – these conditions can cause some strange symptoms that often look like a nutrient deficiency
Pink leaves, red discoloration, rusty spots and edges… While it make look like these cannabis seedlings are experiencing nutrient deficiencies, all these symptoms are actually caused by a combination of overwatering plus a too-small pot.
When the roots aren’t happy, the plant isn’t able to uptake nutrients properly and cannabis seedlings can show a wide variety of strange problems.
It’s usually not a good sign when cannabis leaves start “crossing their fingers” like this (instead of having all the leaf tips spread out). While this can happen naturally every once in a while, you know for sure that you’re having a problem if the crossed fingers are combined with discoloration of the leaves. Also notice how the stems are bright red/pink.
The following cannabis plant was also overwatered and had no drainage. Notice how dark the soil is and the green algae growing all along the top of the soil – these are more signs the plant has been overwatered for quite a while. You should never water your plant when the soil on top is still wet, and if you notice lots of algae growing on top of your soil, it may be a sign that you’re overwatering on a regular basis. Leaving the top of the soil wet is also the number one reason growers get fungus gnats.
No Drainage (or poor drainage)
Cannabis roots need oxygen to thrive, and therefore they will have trouble if the roots are “drowned.” If water cannot run out the bottom of the container, it will pool at the roots, which causes overwatered plants.
- Always start with a good growing medium that drains well – never use a clay based soil which holds onto way too much water. A high quality potting mix (especially mixed with some perlite) provides great drainage
- Start with a smaller container to reduce the chances of overwatering seedlings
- Make sure there are plenty of drainage holes to let water out the bottom of the container
- If water runs through growing medium slowly, you can mix perlite into the potting mix to increase oxygen and quicken drainage
- Water less often and less at a time until plant is drinking more
- Get a container that helps the growing medium dry out from the sides (such as “Smart Pots” – highly recommended; or air pots).
- Don’t allow plants to sit in a tray that has been collecting runoff water
This seedling started “damping off” (dying) due to terrible drainage from bad soil. Never use soil that looks like it contains clay!
Seedling is “damping off” due to bad soil with no drainage
Here’s another example of a seedling damping off due to too much water (drowning roots), whis time combined with not enough light. After a few days of these conditions, this seedling just fell over and started dying.
The following plant was grown in an unsuitable growing medium with no drainage and started showing signs of overwatering. Always start with a quality potting mix that has good drainage, and never allow the top of your growing medium to look this wet!
This “soil” is more like mud. The plant roots are drowning from lack of oxygen, causing severe wilting.
Watering too often
While oxygen is available to the roots immediately after watering, the roots use up all the oxygen quickly if they are sitting in water. If all the oxygen is gone, roots are not able to get what they need to help power growth, at least not until the growing medium begins to dry out and create new air spaces in the growing medium.
Keep roots happy for fast-growing plants
Each air spot in the potting mix provides roots with precious oxygen, but if there’s no air spots, roots start to “drown.” By watering seedlings less often, growers can ensure that roots are getting access to plenty of oxygen at all times.
Of course you should never allow roots to actually dry out – roots need moisture at all times. But for new growers who want to do everything possible for their new seedlings, it can seem like more water = better. Unfortunately, this isn’t true.
Roots work best when they get as much oxygen as possible while also staying completely moist at all times.
- Wait until top inch is dry. Make sure that the top bit of potting mix has started to dry before you water seedlings again. Sometimes it can take a few days, depending on your growing medium, your environment and how much water you provided during the last watering.
- Increase the number of air pockets in the growing medium by mixing in a “lighter” amendment like perlite to the potting mix. Perlite will allow the mix to hold onto more oxygen when mixed with heavy soil. Many cannabis soil growers will mix 30-40% perlite into their potting mix to make sure there’s lots of drainage and plenty of air available for the roots.
- Provide air from the sides. Transplant to a container which allows air in from the sides like fabric pots (“Smart Pots” – highly recommended) or air pots.
- Start in a smaller container until plant gets bigger so there’s less water in the potting mix that needs to dry. You’ll be able to water your plants more often while ensuring they get plenty of oxygen.
- Water less when it’s cold. Plant processes tend to slow down when temps get cooler. This means that plants usually need water less often than normal after a cold snap.
This plant went through a few cool days but the grower continued to water as normal. As a result, the plants roots were surrounded by too much water and the plant started showing signs of overwatering.
The plant was watered the right amount each time, but too often. As a result, it shows some slight drooping. While this won’t kill the plant, the plant will definitely grow faster when the mix is allowed to dry out a bit so the roots are getting plenty of oxygen.
Underwatering – seedling is droopy, wilting, or not growing properly, and the growing medium around the seedling isn’t moist
While overwatering is the most common seedling symptom, underwatering is also a problem, especially for those who have been warned to avoid giving too much water.
It can be confusing because the symptoms often look similar to each other, which is why it’s important to learn good watering practices.
This seedling was underwatered – the grower had been warned many times to avoid overwatering, and went too far in the other direction. Notice that the growing medium looks bone dry.
It’s crucially important to make sure that plant roots have access to moisture at all times. Plants are constantly losing water through their leaves (called “transpiration”) and this is actually how plants get water up from the roots. As the plants lose water from the leaves, it pulls water up from the ground like a straw.
When there’s not enough water at the roots, many plant processes cease to function. If roots actually dry out, the dried shoots die.
Here’s another example of a young cannabis plant that is underwatered, even in a big container (where the problem is usually overwatering). Notice how this cannabis seedling is basically just wilting and falling over, while the potting mix looks completely dry.
Seedlings suffer greatly from being underwatered, even more so than from overwatering. Often the grower will actually be able to see how dry the growing medium is. A big sign that the plant is being under-watered is when you can see the soil separating from the container. In this case, you can see the starter cube separating from the soil because it’s so dry.
Underwatering is bad on it’s own, but it causes the most problems when young cannabis seedlings are also stressed by too high levels of nutrients, or when started in a “hot” (nutrient-enriched) soil.
When underwatering is combined with too much nutrients, seedlings often become dark green and stunted, with twisted and discolored new growth.
The solution for this (underwatering + high levels of nutrients) is simply to give the plants more water so they can establish roots and start growing again. Most plants will be able to grow out of this problem once they get enough water to start growing. While it’s not always the best idea to start out with a hot soil mix, most seedlings will easily grow into it if given a good growing environment.
This cannabis seedling is dark because it was underwatered in a “hot” soil mix, but after watering the plant as normal for a week or two, the plant started growing vigorously
Is a plant drooping because it got too much water, or not enough? Overwatered cannabis plants often have firm leaves, while the leaves of under-watered plants tend to be more limp and lifeless. Both can result in yellow leaves and other odd leaf symptoms. Learn how often you should be watering your marijuana plants!