dead weed plants

Help, My Leaves Are Dying!

I hear this question all the time…

“What’s wrong with my plant? The leaves are…”

Today I will clear up the 3 most common reasons that your marijuana plant’s leaves are dying…

3 Most Common Reason for Discolored Leaves

Other Cannabis Problems & Symptoms

#1 Reason For Dying Leaves: Incorrect pH at the Roots

The #1 reason new growers have dying leaves is because of a pH imbalance . This is because the roots of your marijuana plants need to live in a certain pH in order to properly absorb nutrients. So the pH around the roots will actually affect which and how much nutrients can be absorbed by the plant.

Yes, that’s worth repeating. You will prevent nutrient problems by checking and adjusting your pH in your marijuana grow.

That is why when new growers think they have a nutrient deficiency, often the real problem is that the pH at the roots is off, and the plant can’t get access to the nutrients even though they’re present.

So what is pH?

The pH scale goes from 0 to 14 and measures how “acidic” or “alkaline” a solution is. Below 7 is acidic and above 7 is alkaline. A pH of 7 is the neutral point, and pure water has a pH close to 7.

But that all sounds so complicated!

Checking and maintaining your pH is a relatively simple process that anyone can learn. I have a video below to demonstrate how easy and quick it can be to manage your pH!

Plus, the important thing is to maintain a proper range around your root zone. It’s isn’t critical to maintain an exact pH like 6.2 or anything like that. In fact, it’s better to let the pH range slightly over time because different nutrients like different pH ranges, as you’ll see in a second.

Managing pH: What Do I Need to Know?

You have several options for managing your pH. But no matter what option you choose, youwill need to invest in some way to measure pH.

You can measure pH with…

PH Up/Down or a natural pH adjustment method*

The process of maintaining pH looks like this:

Measure out the water you are going to feed your plants

Add all nutrients and/or supplements to the water

Use one of the options above to test the pH of this water

Use pH Up/Down or a natural pH adjustment method to adjust the pH of your water into the proper range

The optimum pH for marijuana in soil is between 6.0-7.0. The optimum pH in hydro is between 5.5-6.5 (this includes growing in a soilless growing medium like coco coir). It’s a good idea to allow the pH to change slightly over time within the prescribed ranges, especially in hydroponics. Take a look at the charts below to see how different nutrients are absorbed at different pH levels, so you can see why it’s good to let your pH range over time.

Each Nutrient is Best Absorbed at Which pH Range?

What If I’ve been following these steps, but I’m still having problems?

If you’ve been adjusting the pH of the water going in, but are still having nutrient deficiencies, check the pH of the water coming from your roots . So this means check the pH of your runoff water(the water that drains from your flower pots), or the water in your reservoir.

You may find that the pH is higher or lower than expected. This is why it’s important to check the pH of the water coming from your roots when you’re running into nutrient problems.

For example, let’s say you watered your plants with nutrient water adjusted to a pH of 6.0, yet the runoff water is coming out with a pH of 4.0. This often happens because there is nutrient/salt buildup around the roots (usually from adding too many nutrients over a period of time). You need to remove the buildup. A common way to remove salt buildup is to flush the plant with about 3x as much plain, pH’ed water as normal. Then go back to your normal feeding schedule (make sure you check the runoff pH again afterwards, to make sure that your flush worked).

In hydroponics where the roots are growing in water, it is common for the pH to rise over time. This is partially because oxygenating your water (for example using an airstone) actually raises the pH. This is why it’s important to keep checking the pH until you’ve grown familiar with how the pH tends to play out with your system and your water/nutrients.

Wait, why do I need to check the pH of my run-off water?

The pH of your soil or potting mix can fluctuate as nutrients/salts begin to build up. This happens most often when you are regularly feeding more nutrients than your plant can use.

Checking the pH of your run-off water is an important step to diagnose problems with the pH around your plant root zone. This step is especially important for new growers and those who are having issues with nutrient deficiencies.

If the runoff pH is much higher or lower than expected, chances are you have unused nutrients or salt build-up near the roots that are raising or lowering the pH of your root zone.

When this happens, you can remove this buildup by flushing your soil or soilless mix with about 3 times as much pH’ed water as the volume of your container. You can also flush your plant to remove extra nutrients if you’ve over-fertilized your plants and they’re showing signs of nutrient burn.

This will wash away the buildup and help “reset” the pH of your root zone back to the proper level.

Some growers choose to flush their plants every 3-4 weeks regardless of whether they notice problems to prevent buildup, though this is usually unnecessary unless you are chronically overfeeding with nutrients.

After someone has been growing the same strain of marijuana, in the same medium, with the same nutrient solution, etc. for a while, chances are they will become very familiar with their growing style and won’t need to check the pH of their runoff water unless they notice problems.

Show Me Step-By-Step: How Do I Check the pH of My Water?

NOTE: The the blue and orange pH up/down bottles you see at hydroponic growing stores are not designed for organic growing. While some growers believe it is okay to add pH up/down in small amounts after you’ve mixed your nutrients into your water, other growers feel this may kill the microorganisms that make organic growing so effective.

If you’re an organic gardener and worried about using pH Up/Down, there are natural ways to adjust the pH that definitely won’t harm your living soil.

A cool fact about pH:

The type and amount of nitrogen used in a nutrient bottle has a big effect on how much it will affect the pH of your water.

Using this knowledge, a smart grower could buy or mix up nutrients based on the current pH levels of their water so that their nutrients auto-correct the pH.

#2 Reason For Dying Leaves: Watering Plants Incorrectly

Ok, you have successfully made sure you’ve corrected the pH, and you’re still seeing dying leaves, or leaves with problems.

Chances are you have a watering/root problem.

When growing in soil or a soilless growing medium like coco coir, this is usually caused by poor drainage, or over/under watering.

To properly water your marijuana plant every time, use this technique:

Every time you water, add enough that about 20% extra runoff water has drained out the bottom (if you don’t have drainage holes, or if water isn’t draining, this needs to be fixed immediately or you will run into lots of other problems).

After you’ve watered your plants with 20% extra runoff, then don’t water them again until the growing medium is dry enough to stick your finger in to about your first knuckle without feeling moisture.

In hydroponics where you’re growing with your roots directly in water , a root problem doesn’t result from over/under watering, since you don’t water your plants.

The problem in hydro usually results when plant roots start “drowning” because they can’t get access to enough dissolved oxygen in the water.

The way to fix this is to oxygenate your water with an air stone, or otherwise get more oxygen to your plant roots.

In both soil and hydro, you can also see signs of root problems because of a condition known as “root rot.” This condition will give you brown, mushy, smelly roots.

Root rot is often the result of bad watering practices, high temperatures, or poor drainage, but sometimes root rot can appear out of nowhere.

When this happens, a great cheap supplement that seems to completely decimate root rot is Aquashield. There are also other root supplements that are more expensive such as Great White and Subculture B, but I’ve always had the best results with the much cheaper Aquashield.

#3 Reason For Dying Leaves: Nutrient Problem

Ok, you’ve ruled out the #1 and #2 most common reasons for dying leaves. You may actually have a nutrient problem. will teach anyone with any budget how easy it is to grow their own cannabis.

Causes of death in plants during the growth period

Causes of death in cannabis plants during the growth period

The vegetative growth of cannabis plants can be one of the longest periods of cultivation when growing outdoors – or indoors – where in, for example the countries of southern Europe they enjoy a lengthy spring and summer. During the course of this growth phase, problems can arise that may lead to the death of the plant even before the flowering stage begins.

Let’s see what are the most frequent causes of death during the plants’ growth period and what we can do to avoid a premature, unhappy ending.

Cannabis plants in vegetative growth

Overwatering cannabis plants

The most common cause, especially among beginner growers, is undoubtedly overwatering. The excess of irrigation particularly affects young plants in their first weeks of life (although it can also occur with larger plants).

The main reason is watering too much, too frequently. Small plants have a very limited resistance, partly because of their size. A plant with two cotyledons and three small roots can not cope with large amounts of water, simply because they can not process it, not having sufficient absorption capacity in the root zone.

The growth phase is crucial for an abundant bloom

If we overwater our plants, the substrate will be permanently wet, meaning the roots will not get enough oxygen and they can begin to rot, falling prey to various fungal pathogens that are capable of killing the plant in just a few days. Depending on their genetic inheritance, there are varieties that are are better or worse adapted to withstand an excess of irrigation, for example Afghani genetics such as Northern Lights; originating in a dry, arid climate, they can not tolerate continuous moisture in the root zone. On the other hand, cannabis plants with tropical ancestors will tend to have a greater resistance to root rot, as in the case of the world-famous Skunk.

To avoid a plant suffering from excessive watering during its cultivation, first we need to be careful not to swamp the substrate. If this happens, let it dry before watering again. Avoiding heavy substrates with too much clay will also help, remember that the roots also need oxygen!

A long period of wetness in the substrate means that the roots can’t transport food to the upper parts of the plant, which will feed from its nutrient reserves, causing the smaller leaves to lose their colour gradually, from a pretty green to a yellowish shade.

Overwatering in a small plant

Once the leaves of the plant change to a yellow colour due to excessive watering, root rot will often come next, and with it the consequent death of the plant. Another symptom of possible overwatering is if the plant appears to be wilted (with droopy leaves) even though the substrate is moist.

The most harmful fungal pathogens for cannabis plants

Pythium, Fusarium and Phytophthora are the 3 most harmful moulds to cannabis plants, capable of killing them in a very short time and with almost no possibility of treatment. Prevention is always the best method to combat these fungal pathogens.

Healthy roots vs rotting rots

These fungi come into contact with the plants via the roots, usually due to root rot or any decomposing organic matter such as the fallen leaves of the plant that remain on the soil surface. For this reason it’s important to remove any dead leaves from the substrate where they could cause a fungal infection.

Another way to protect the roots against fungal attacks is through the use of microbials, with the fungus trichoderma. This type of microbial life protects the roots while optimising nutrient uptake to the plant much more effectively than in a lifeless substrate.

This beneficial fungus colonises the roots and leaves no room for harmful fungi to settle on them, and if they do, the trichoderma takes care of eliminating them. This type of microbe can be used any time from germination until harvest, although ideally we’d use it from the beginning and maintain it in good conditions, or keep adding it with each transplant. Using sugars and carbohydrates helps the micro-life to stay active throughout the grow.

Botrytis at the tip of a lower branch

Drought or under-watering

A lack of water, or drought stress is another of the principal factors that can seriously affect plants and cause premature death. The plants require water for their survival, and if they run out of it for a few days or even hours (depending on the cultivation system) they can die very easily.

Even if the plant manages to survive the drought period, it’s inevitable that part of the root system will be affected. When part of the root system dries out and dies, it is usually accompanied by some of the leaves and branches, which will weaken the plant and reduce it’s capacity to process nutrients, impacting negatively on development and translating into a smaller final harvest.

Lack of water led to this plants death

If this period of drought is repeated or is too prolonged, the plant may not be able to survive as well it could the last time, as its root system is now much less extensive than it was initially. Remember that you can use products to stimulate root growth, helping the plant to develop more roots and therefore feed more efficiently and more able to tolerate any periods of drought.

Lack of light in the grow

Although it is not very common in outdoor gardens, where fortunately the sun is always present, in indoor cultivation a lack of illumination could occur for various reasons: if we have a blackout, a bulb fails, the timer doesn’t work properly, the ballast stops running unexpectedly or if we have some other problem with the electricity supply or our installation.

Cannabis plant after 2 days without light

In this case, the plants can last for a few days without light, although they will be greatly weakened and more likely to experience possible rotting of roots and leaves if the humidity in the grow space is high. Initially, the upper leaves will take on a yellowish color due to a lack of chlorophyll, as the plant can’t carry out photosynthesis properly.

Too much light in the grow

Lights that are too powerful or too close to the plant can dehydrate the leaves, curving the edges upward (indicating a lack of transpiration). When the stomata – which are small holes in the leaves where the plants breathe – close, the plants can not “breathe” properly, and if we add to this a very low humidity, they can dry out quickly and end up dying. Therefore, it is vital to carefully select the proper type of lighting for a cannabis grow.

Lack of transpiration due to low humidity

Excess of fertilisers, nutrients or salts

Plants require food to be able to grow, but an excess of fertiliser could kill the plants if we don’t take quick action to remedy it.

Organic fertilisers don’t tend to over-fertilise plants because they release nutrients slowly. If using mineral fertilisers for cannabis, this possible problem must be taken into account if we want to avoid problems.

To find out if the substrate has an excess of mineral salts, we need to monitor the EC of the drainage water. If the runoff comes out with a similar EC to the inlet (the one used for irrigation) then everything is correct. However, if the EC of the drainage water is much higher than the inlet water, a root-flush should be performed to wash the excess salts out of the substrate. Using enzymes in each irrigation helps keep the substrate free of salts.

Insect infestation

Insect pests can be many and varied, and although not all are 100% fatal to the plant, many of them are capable of devastating our garden if they’re not treated properly. Of course, it’s always possible that the plant will survive the infestation, but a serious insect attack will almost always lead to weak plants and lower yields.

One of the most feared insect infestations is the stem-boring caterpillar, which eats into the central stem and hollows it out. The flow of the sap is obstructed, halting growth and after a few days the plant ends up wilting and dying. It can be very difficult to detect with the naked eye and to find it you’ll need to look for holes in the stem, usually beneath the nodes of the non-woody parts which have more tender vegetable tissue that’s easily edible by the caterpillar.

Insects can quickly ruin your harvest if not treated properly

Red Spider Mites are also one of the most common and devastating pests if not treated in time. In addition, their eggs can remain dormant for a long time, ready to hatch and infect the crop again when the conditions are right for their development.

Snails and slugs can be very harmful when the plants are very small and don’t yet have a lot of leaves. If the plant only has 4 leaves and these small devourers eat them, it will not be able to transpire or capture solar energy for photosynthesis, which can seriously compromise its development.

Insect damage on cannabis leaves

Fungus gnats, nematodes, aphids, or any root-feeding insect can cause the plant to lose its vigour during the growth period, meaning that the flowering phase can be seriously affected.

Extreme temperatures: hot y cold in the grow

Extreme temperatures – both cold and hot – can be lethal to plants. In winter, the cold can be controlled using radiators indoors, and even in outdoor cultivation through the use of greenhouses.

Keep in mind that if the temperature drops below 12ºC, the plants may die. From 12 to 16ºC the plants growth is halted as they become dormant, as if they were hibernating, but essentially what they do is completely slow their metabolism down to keep alive while waiting for the climate to improve.

Cannabis in cold conditions

A temperature lower than 12ºC can kill the plant in case of prolonged exposure and it is not remedied. They can also die by freezing when the temperatures get as low as 0°C.

On the contrary, extreme heat is another factor that can cause the plant to die. Although it is less harmful than the cold, it also ends up severely affecting the development of the plant in all its stages of life, hindering its transpiration, nutrition and cellular development.

With high temperatures the roots can be “cooked”, for this reason when growing outdoors we recommend using white pots instead of black, and if possible to cover them from the direct impact of the sun using insulating material.

Indoor grow tent with temperatures close to 40ºC

Dehydration is very common in high temperatures, since the humidity of the substrate will evaporate more quickly, the roots dry out, the stomata close and the plant cannot transpire and will not develop with the proper vigour and vitality.

To fight against extreme temperatures in an indoor grow, air conditioners or radiators can be used. In the case of an outdoor crop, you can use greenhouses against the cold and shading mesh to protect plants from the suffocating heat of summer.


These are the most common causes of death in young cannabis plants. Remember that depending on the case, this can happen in a very short time and if we don’t take action, the plant most definitely will end up dead.

It should be noted that, although these are the most common causes, they can occur with greater or lesser ease depending on the growing conditions that the plants have to endure. Of course, if a substrate is used that is not suitable for cannabis cultivation (such as field clay), problems with the roots may be more present than using a suitable substrate for cannabis.

Cannabis plant in a clay soil, a completely unsuitable substrate

A lack of ventilation in the cannabis grow space can facilitate the appearance of fungi due to stale air and excessive heat in the environment, as well as a lower evaporation of moisture from the substrate. In turn, this encourages the possible appearance of insects such as white flies or fungus gnats, in addition to promoting the appearance of fungal pathogens such as botrytis, pythium or fusarium.

In many cases, where problems discussed in this article arise in the grow, it is usually due to poor management of the environment or not taking into account the needs of the plants when selecting the appropriate substrate or fertiliser. One simple error in a cannabis grow can cause the appearance of other problems that are even more devastating, so for this reason it is important that all aspects of the crop are well under control before starting out on the grow adventure, and avoid nasty surprises such as the premature death of your plants.

Related Posts

Deficiency and excess of magnesium in cannabis plants

Deficiency and excess of Iron in cannabis plants

How to grow cannabis plants in coco coir

Deficiency and excess of Phosphorus in Cannabis plants

Comments in “Causes of death in plants during the growth period” (13)

Limakarli 2020-11-20
So, i,ve transplanted my plant, maybe a fee days to late, it got to big for the container, the roots where sticking out from the bottom, now the plant is in a bigger container and it’s wilting, the leaf stems are purple, but the color of the leaves is normal. Will my plant recover?

Tim Alchimia 2020-11-20
Hi and thanks for your comment and question. It’s quite normal for plants to suffer a certain amount of shock when they are transplanted, so we can expect a little wilting and for them to look a bit sad for a few days. Purple stems are a sign of this stress. I often use a kelp meal solution when transplanting, which helps mitigate stress somewhat, it can be applied both via irrigation and foliar spray. In any case, as long as the new substrate is good quality and not too “hot” (high in nutrients) then your plant is almost certain to recover in a short time. I hope that reassures you, best wishes and happy growing!

Young c 2020-11-02
I’ve been growing my plant for bout 4 weeks now n yesterday I transplant it with an all purpose soil n the soil I had my seedlings in n tdy when I saw it my plant is bent over flat on the soil. What can I do to fix this issue?

Tim Alchimia 2020-11-03
Hi, thanks for your comment and question. You need to gently straighten the plant upright again, then carefully firm the soil around the base of the plant before using a cane or two along with some plant ties to support it and keep it upright. Be sure to check and change or remove the plant ties as the stem grows, they can end up restricting and biting into the stem as it gets bigger. I hope that helps, best wishes and happy growing!

Zee 2020-07-23
Hey there, I’m a total beginner in growing and I had a couple of seedlings dying on me, my simplest question is, are they revivable after they die? By cutting everything that’s above ground?

Tim Alchimia 2020-07-23
Hi Zee, thanks for your comment and question. I’m sorry to hear about your seedlings dying, and I’m afraid that they won’t regrow if you cut them back to ground level. There needs to be at least one node (the joint where branches form on the main stem) on the plat to allow any kind of further growth to occur. The best thing to do would be to try and work out why exactly the seedlings aren’t surviving and deal with that issue before trying to grow any more. Do you have any idea why they might have died like that? Best wishes and happy growing!

Zorstorm 2020-07-11
i have 5 plants outside in the same area, same dirt, same irrigation, all five were super great, nice, growing fast and strong, then yesterday i went and checked and one is litteraly a limp biscuit i thought with the extra rain from lsst night it would perk up. Notta. Its still pretty much toast. Ill send a pic but there isnt a way to add a photo. In canada here so im not worried about posts lol.

Tim Alchimia 2020-07-13
Hi Zorstorm, thanks for your comment. I’m not sure a photo would help much, if you can’t see any obvious physical damage to this particular plant, then it sounds like there’s either some kind of pest or pathogen attacking the roots. It could be a fungal infection of some sort, you may see damage around the base of the plant, or possibly some kind of boring insect has burrowed into the stem, halting the flow of nutrients and water to the rest of the plant. Alternatively, something could have eaten the roots, I’ve seen plants destroyed by voles or gophers. I’ve even seen plants badly affected by the presence of an ant’s nest in the root ball, resulting in a completely wilted plant. My advice would be to remove the affected plant to try and work out what the problem is and to prevent it from spreading to the rest of your plants. I hope that helps, if not then try sending us a photo to [email protected] and we’ll see what we can do to help. Best wishes and happy growing!

John 2020-05-03
Hello Please can you help, I have 16 plants growing in a tent using hydroponic techniques . The problem i have is that one out of the 16 plants is wilting while the other 15 seem healthy, This has occurred a couple of times. Any advice would be grateful. Thank you

Tim Alchimia 2020-05-07
Hi John, sorry to hear about your plant wilting. Without being able to see it, I’m guessing it’s happening because that particular plant either isn’t getting enough nutrient solution or it’s getting too much irrigation, which is causing root problems and possibly fungal issues. You said this has happened to you before, so is it always the same position in the hydro system that is affected? I would check the dripper lines and ensure that there isn’t a blockage preventing the plant from being irrigated, or for a damaged dripper that could mean the plant is getting too much water. Also, check the condition of the roots, they should be white and thick when they’re healthy. Stringy, yellow/brown roots indicate a problem. I hope that helps, best wishes and happy growing!

Nathan 2020-03-29
So I just started an auto flower grow in my window seal but moved them to an indoor grow but I started 5 an overtime each plant would just gradually fall over then shrivel off an die so far 2 have died and a third just started to falling over (2 felling while living in window seal)

Tim Alchimia 2020-03-30
Hi Nathan, thanks for your comment. I’m sorry to hear that you haven’t had much luck with your seedlings. It’s hard to know what could have gone wrong without more info, but I can try. Does the window sill get full sunlight all day long? It could be that the seedlings are stretching too far to reach the light and falling over as a result. Conversely, it’s always possible that the seedlings have got far too hot on the window sill, and the shrivelling up is due to heat stress. A thermometer/hygrometer will help you to work out if the window sill is too hot or not. Other possibilities are overwatering, which can easily lead to a condition called “damping off” aka fungal pathogen Pythium. If you check out our blog post on the subject, it may help you to identify the problem and prevent it from happening in the future. Any more details you could give us would be very useful in determining the cause. Best wishes and happy growing!

Fredo 2020-03-28
I recently attempted container growing and it was a complete failure. My plants typically stop growing after a week, followed by crunchy yellow/spotted leaves. I know my problem is the roots but cannot figure it out. Fine roots circled the bottom of a solo cup and the plants were not stable to transplant when they stop growing,weak at the stalk-root junction,but I transplant anyway and get another week of growth yet roots are not developing ,barely elongating downward,not lateral and still very very fine. I just checked my organic soil pH and it appears in range,(if we can trust a 25 minute slurry soak tested with pH drops, allowing for whatever sediment passed through the coffee filter to settle,the color matches 6.5ph)My temperatures are in the 80s and humidity is low but plants look amazingly healthy up top aside from some twisted and pale new growth that always straitens out. I did raise humidity with wet towels for a couple weeks,and lowered temperature below 85 and got less growth than ever. The bottom leaves get crunchy and die. The main stalks are thin and woody until the first node ,then thicker up top where they are not woody. Purple coloration has come and gone on some plants. Most seedlings appeared purplish, some looked blue but I’m using “Clackamas coot” soil recipe and shouldn’t have Phosphorus deficiencies, especially since there’s only a purple petiole here and there with bigger plants. My medium is 33% rice hulls and I began waiting for plants to sag before watering to make sure I wasn’t over watering (I wasn’t). The plants range from average to dark green with no signs of heat or nutrient burns,and always perk up within hours of watering,but do not grow. The only way I’ve been able to bring these tiny compacted plants to harvest is to continually repot, sometimes in the same pot sometimes bigger, sometimes smaller, it does not matter,the roots will not develop, still as frail as the first week. They are all tiny and only the male stretched at all after I bloomed them. I was able to pollenate and can see big white seeds busting out of the calyx but I’m afraid even their development has been halted and I won’t even get any viable seed out of this 5 month long failure. Yes,I have uncropped plants 5-7″ tall planted last November. I was certain it was low pH but my test and having followed everyone’s recommendations (2 cups of calcium vs 1 for the acidity of the peat). Why won’t my plants grow? It pains me only that one of these plants, the smallest one, would have been a keeper, putting off the crazy rich sour skunky smells that do not exist in today’s market,but it never got big enough to take cuttings from. It also pains me that I now live in the Sonoran where guerilla growing is no longer an option,and where there is limited availability of acceptable Cannabis. Will I ever figure out indoor container gardening? Should I pray to the Rhizome gods?

Tim Alchimia 2020-03-31
Hi Fredo, thanks for your comment and question. It sounds like you’re doing everything right so I wonder what the issue is. Has this only happened with your last grow cycle? Or is it a problem you’ve had with previous attempts? Just checking that it couldn’t be this last batch of seeds or clones that might be lacking vigour. If you started with clones then it’s always possible that they came with uninvited visitors, for example, root aphids. These are hard to see, even harder to eradicate and can cause some serious problems to your plants. If you’re sure about your source of clones or seeds, then the next thing to do is to eliminate possibilities, so try a good quality soil mix from a grow shop and do a side-by-side comparison. From what I’m reading about rice hulls, they are very effective at reducing soil acidity, so if you’re also adding lime then maybe the issue could be too low acidity. Have you tried adding any microbial inoculant products? A good quality mycorrhizal supplement can make a huge difference to plant health and vigour. That’s always my go-to if I suspect an issue with the roots. It won’t help much with any insect pests down there, but it will improve soil health and help the plant to uptake nutrients. On another note, I don’t think that constantly re-potting the plants will help them develop faster. If anything, the stress of transplant will hold them back. I always feel like it takes my plants a week or so to recover from transplanting and get back to vigorous growth again. Sorry that I can’t offer much more advice at this stage, maybe a bit more information about the genetics you’re growing could help. Till then, all the best and happy growing!

Jackie 2020-03-10
Why is my plants leaves wilting and dying at the top only ?

Tim Alchimia 2020-03-17
Hi Jackie, thanks for your comment. I’m sorry to hear your plants are wilting. It’s going to be difficult to diagnose the issue with such little information, but these things are usually caused by over-watering, so I’d double check that as a first measure. If that doesn’t do the trick then if you can provide any further information I’ll try and work out what the problem is. Best wishes and happy growing!

Don 2020-02-05
Thank you for your fast reply ! Yes that was my question and yes it goes well without liquid fertilizer. I only added mycorrhiza at the beginning. But i think that if i do this with a non-auto variety i’ll have nutrition problems.

Don 2020-02-04
Hi, I have a question about indoor growing. I use plaxon light mix soil, for a autoflowering variety. Do i have to rinse (2 weeks before harvest) even if i didn’t use liquid fertilizer ? Thank you

Tim Alchimia 2020-02-05
Hi Don, thanks for your question. So, to clarify, you’ve not been using liquid fertiliser but instead just irrigating with plain water throughout the plant’s life? Just out of curiosity, how did that go with light mix soil? Did you experience any nutrient deficiencies? If I were you I’d simply carry on irrigating with plain water right till the end, because if I’ve understood you correctly, you’ve effectively been flushing the plant throughout its life so there oughtn’t to be any fertiliser residue in the substrate at all at this point. I hope that’s some help, please let me know if I’ve misunderstood your comment. Best wishes and happy growing!

Clearhead Fred 2020-01-30
Up until a year+ ago I had beautiful grows. Then instantly a grow went bad in bloom mode. Plants all yellowed with variying types of lear damage visible. Wayyy to many possibilities. Since that grow NO plants will grow any bigger than 2″ to 6″ and die off. Doesn’t matter what strain. Tried four different soils. Completely tore down to all walls in the rooms and put up all new OSB, plywood, flooring, a light bleach mix sprayed all over heck and creation. Rooms set idle for two months. I stsrt dcdomecseeds. Seedlings came up ok. Got to 2″ and stopped growth. Never got past the initial two leaves. This was within 10 days of coming up. If you can think of it, probably has been looked at. Once again it does not matter what strain. RO water to creek water to another well Nope. What could possibly be in the air itself within our home tjat could be doing this. Closing the stomato so it can’t breathe which in turn no uptake and then death. We’ve done the pythium attack. You make it. Your input? No it’s not nute lock. Lol

Tim Alchimia 2020-01-31
Hey Fred, thanks for your comment. I’m really sorry to hear about all the trouble you’ve been having there. That sounds dreadful, there’s obviously something seriously wrong for plants to die after such a short time. Have you checked with a microscope for mites? I know there are some microscopic mites that can cause chronic infestations and are very, very difficult to get rid of, even with all the measures you’ve taken. That’s really the only thing that occurs to me here if you’ve looked at everything else. The only other thing to do is to think back to that time roughly a year ago when things began to go wrong and try to remember if there was anything that changed from normal, not just in the grow itself but in the rest of the building and the surrounding area as well. Is there any way you can check the air quality in your home? Something must have changed to cause such a marked difference in results before and after. I’m sorry I can’t shed any more light on the subject, but I’m really curious now. Please let us know if you make any progress. Best wishes and good luck!

Candace 2020-01-12
I accidentally pulled my stem up I replanted but its wilted what should I do??

Tim Alchimia 2020-01-13
Hi Candace, thanks for your question. Sorry to hear about your unfortunate accident, hopefully, the plant will recover. I’d be irrigating with some kind of kelp solution to help the plant deal with the stress of the “transplant”, and a root stimulant to encourage new roots, but its survival will depend on a few factors, such as how badly the roots were damaged and how big the plant itself is. If it’s a small, young plant with few leaves then it can recover quite fast and get back to normal. Of, however, it’s a larger plant with lots of foliage it will have a harder time recovering because more leaves mean more demand for water, which the damaged roots can’t keep up with. You can help by removing some leaves, which will put less strain on the recovering roots (when the plant wilts it is telling you that the water available to it isn’t sufficient to keep the leaves alive). I hope that helps, all the best of luck and happy growing!

Natasha Crayton 2019-11-17
Greetings, My cannibis plants have been leggy for a long time. They are a few months old and have not flowered yet. Can I top off stem with new soil or will it rot or erode the stem?

Tim Alchimia 2019-11-19
Hi Natasha, thanks for your question. Firstly, yes you can certainly pile more soil around the stem if the plants are very stretchy. As long as the soil stays moist and isn’t water-logged then there shouldn’t be any problems with the stem rotting. Some varieties will readily grow (adventitious) roots from their stem, while others will find it a bit more difficult. An application of beneficial microbes such as Trichoderma will help to keep any pathogenic infections at bay. However, If your plants are still in vegetative growth and you’re concerned about not having enough headroom, you could always try pruning or training your plants to control their height. You say your plants are a few months old but haven’t flowered yet. are you growing indoors or outdoors? If indoors, are you waiting for a certain time before switching them to a flowering photoperiod? Choosing the right moment to flip to flower is crucial if you want to make the most of the grow space, too soon and they stay smaller, not taking full advantage of the headroom, whereas if you let them grow too big during vegetative growth they will outgrow the space available to them. I hope that’s some help. All the best and happy growing!

Cannabis plants can die for various reasons, even during vegetative growth. Let’s see which are the most common causes and how to avoid our plants hav