Environmental issues that cause marijuana plants to stress

The environment produces most of the factors that will determine the health of your weed plants. From air quality and humidity to temperature and light, keeping the environment of your plant maximized will decide whether or not you have a strong, healthy plant, and a big yield to go with it.

It takes a lot of work to keep the environment well-balanced, but the end result is worth it for most growers. You’ll need to keep the pH levels, nutrients, and growing seasons in mind when attempting to optimize the environment.

Not only will optimizing the environment get you a bigger yield, it will also be better. What grower doesn’t want to produce the highest quality product possible?

Read this article and learn how to recognize and treat stressed out weed plants. Every subject has a link to a more in-depth article.

Cannabis light stress: dark cycle interruption

Plants are extremely sensitive to changes in light. That’s how they grow, and how they know that seasons are changing. Changes in the intensity and schedule of light exposure will radically affect the growth of the plant.

dark cycle interruptions

Outdoors, your plants will get all the sunlight they need for natural seasonal changes, but indoors you need to carefully manage all of the lighting to make sure the plants are growing well. If you’re growing indoors, you can’t rely on the plant to ‘know’ when it should be flowering and maturing. You have to help it more than you would a plant that’s being grown outside.

Before flowering begins, every cannabis plant needs to undergo a period of uninterrupted, total darkness. Every strain is slightly different in this regard, but be absolutely sure that the plant isn’t getting any light during this crucial period, or it won’t flower properly. Read more about dark cycle interruptions.

Download my free Grow Bible for more information about the light cycle of marijuana plants.

Cannabis humidity and temperature stress

Cannabis is an unusually hardy plant, and it can survive in a wide variety of conditions, but that doesn’t mean it will thrive in less than optimal conditions. If your grow room is too hot or too humid, it’s quite likely that your plant will become stressed, and they won’t grow to their full potential. If there is too much humidity, you can simply invest in a dehumidifier. It uses electricity, but it will replace the moist air with drier air. All you need to do is empty the reservoir regularly.

humidity and temperature in your marijuana grow room

When it comes to temperature, cannabis plants like it hot, but there is a point at which it can become too hot. Anything over 80 degrees Fahrenheit is likely to be less than beneficial for most varieties. If your grow room is too hot, you can use air conditioners to help cool it down. Alternatively, you can cycle cool water through the root systems to allow the plant to cool itself. Read more on what do to when your marijuana grow room gets too hot or humid.

Stress from pruning weed plants

Pruning can be beneficial to the overall health of your plant if it’s done right. Farmers frequently prune plants so that they can get a better harvest out of an individual plant.

pruning cannabis plants

Done properly, pruning will help you maximize your yield, but it is absolutely essential that you know what you’re doing if you start pruning. If you aren’t sure about what to do, you’re much better off not pruning at all.

Also read “Pruning marijuana plants

If you prune your plant excessively, it won’t be able to produce as much energy, and so it won’t produce as many buds in the long run, and those buds that are produced will be smaller.

Airy and loose buds

Airy and loose buds are usually considered to be of lower quality than the tight firm buds that smokers favor. The looseness of the buds can be caused by a wide array of environmental factors, ranging from too little light or nutrients to too much heat.

an airy and loose marijuana bud
Airy and loose bud

For most growers, a high temperature is the guilty party. If your grow room is getting you loose buds, consider adding an air conditioner to your setup to help cool the room. You can also experiment with moving the plants around so that your room is better ventilated. If you’re growing outdoors, you can help ameliorate loose buds by using a micro-sprayer system.

By using perfectly balanced nutrients available in my own Marijuana Fertilizer, you will most likely be able to prevent Zinc deficiency in any of your future grows! If you wonder how and when to use the nutrients, please check out this feeding schedule.

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Prevent future deficiencies

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If your plants don’t get enough potassium during the flowering process, you can also get loose, airy buds. If you think that might be the case, simply switch to a fertilizer that gives you a higher concentration of potassium.

Read more on “How to avoid airy and loose marijuana buds“.

Clone stress: Cannabis clones won’t root

Your primary goal when it comes to cloning cannabis plants is to get those fresh young cuttings to root properly. You can do it manually, but there are some additional helpful tools you can take advantage of as well. For example, sometimes your cuttings won’t root well, but if you just apply a little bit of rooting gel and tweak the environment, they will root nicely.

cannabis clones wont root

Many growers also wonder whether or not they can take cuttings from fully mature plants or plants that undergoing flowering. Yes! You can take cuttings from plants at practically any stage of growth after it splits out of its seed. Giving it a little bit of time to grow and root beforehand is usually a good idea, however. As long as you take care of those cuttings, they should grow nicely. Learn how to make clones.

Stretching weed plants

Another problem growers can experience is having their weed plants or seedlings stretching too much. Usually, these long spindly plants stretched out because of a number of environmental factors, often light-related.

stretching cannabis plants

Stretched weed plants are unable to support proper branches, leaves, and buds. The stems are just too thin. Keep an eye on your plants to make sure this isn’t happening to you! If the stems aren’t developing enough, you can gently bend the stem back and forth. While this might seem counterintuitive, damaging the plant, a little bit will force it to devote some energy to strengthening and re-growing the stem.

You can also solve this issue by adjusting the spectrum of the light you’re using, and making sure that the temperature is hot without being overly hot. Make sure the plants are getting plenty of light, or the plant will stretch out in an attempt to reach the lights. Find out how to deal with stretching marijuana plants.

The ideal marijuana growing temperature

If your marijuana plant is exposed to unusually high or low temperatures, that can stress your plant in a number of different ways. Ideally, you should keep the environment close to 80 degrees Fahrenheit, but it will do well near this as long as it isn’t too hot.

lower temperature growing cannabis

The temperature can drop up to 15 degrees during periods of darkness if necessary, but be careful. Temperatures that drop too low end up slowing the growth of the plant significantly. When it comes time to harvest the buds, you’ll notice a decreased yield to go along with the slow growth. Unfortunately, you won’t notice this until it’s too late. So do yourself a favor and make sure that your grow room is hot enough! Keeping a close eye on the environment is key.

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The flip side is making sure that your grow room doesn’t get too hot. If the temperatures are too hot, the plants can be damaged. You might experience weak stalks and stems, as well as wilting droopy plants.

Read more about the ideal temperature for marijuana plants.

Consider your ventilation in too-hot grow rooms, and possibly adding an air conditioner if you’ve already run out of other options in how to adjust the ventilation in your plant’s environment.

Hermaphrodite weed plants

Hermaphroditism is not a good trait for growers of indoor weed plants. The problem is that if the plants possess both genders, they can pollinate themselves and the other plants around them. One single hermaphrodite plant can pollinate an entire grow room. Unfortunately, pollinated plants produce much lower quality buds, and the smoke is undesirable to most medicinal and recreational users.

hermaphrodite cannabis plants

While stress can theoretically cause hermaphroditism in weed plants, it’s usually predetermined by the plant’s genetics. Remember to avoid any major stresses that can induce the plant to become hermaphrodite.

For example, it’s possible for your plants to grow just fine outdoors, but if you move them indoors, the stress can cause them to produce male flowers and exhibit traits of both plant genders. If this happens, your only option is to quickly try and pick off the male flowers so that the plant doesn’t self-pollinate.

Read more about hermaphrodite cannabis plants.

You’ll also want to separate it from the rest of your growing operation so there’s no risk of pollination there either. Also, try not to use seeds from hermaphroditic plants, because every subsequent generation will run the risk of self-pollination.

Cannabis seeds won’t germinate

Sometimes cannabis growers will have a huge issue at the beginning of their cultivation. The first issue you can have is seeds that just won’t germinate. There are a number of factors that can influence a seed’s inability to germinate.

marijuana seeds wont germinate

Usually, a seed should just need water and a warm environment, but if you’re having trouble, you can try soaking the seeds in a heavily diluted solution of hydrogen peroxide and water. This will weaken the seeds outer coating and make it easier for the seedling to pop out.

Read more about why sometimes cannabis seeds won’t germinate.

Also, seeds don’t last forever. If your seeds are too old, they might never germinate, and you’ll have to throw them away. Read more about why sometimes cannabis seeds won’t germinate.

Knocked down weed plant

Cannabis plants are tall and thin, and sometimes they can be knocked over by storms or unusually heavy winds. But remember, cannabis plants are hardy! If your plant gets knocked down, it might still be able to survive.

What To Do When Your Marijuana Plant Was Knocked Down

You should get the plant back into position as soon as possible and repair any of the breakings that might have damaged the stem. Make sure that the plant is firmly rooted and stabilized against any future winds. Stakes can help you support a plant, much like a brace or cast helps support a broken leg. You can use tape to help repair breaks in the stem, as a sort of bandage.

Find out what to do when your cannabis plant was knocked down.

If the roots are ripped out of the soil, you need to make sure you get them covered back up. Roots don’t deal with exposure to light and air, and if the roots aren’t pulling in water and nutrients from the soil, the plant will die.

Hard or soft water for weed plants

Water is the foundation of all life on Earth, and your cannabis plant is no exception. The thing is, water can contain a lot of different elements and minerals. You should test the water you’re giving your plants to make sure it’s not full of anything undesirable.

hard or soft water for marijuana plants

Tap water can often contain chlorine, sodium, sulfur, and other bad stuff that your cannabis plant really doesn’t need to thrive. Hard water contains any number of dissolved solids, and you should be aware of what you’re giving your plant so that you can fertilize it properly.

If you find out that your water contains undesirable minerals or elements, your best bet is to use filters to purify it. Try to avoid water softeners, as these may fix one problem, but might add other elements you don’t want.

Read more on what water to give your marijuana plants.

Growing marijuana can be challenging but the reward at harvest time is definitely worth it! Know the best time to harvest your crop with my free mini harvest guide!

Bad weather conditions for outdoor weed plants

Outdoor growers of cannabis don’t have the same luxuries as indoor growers. Inevitably, you’ll have to deal with unpredictable weather. Extreme cold, long periods without rain, and periods of heavy rain can all cause issues for your crop.

cannabis and weather

If your plants are cold, they’ll stop growing, and if they stop growing for too long, they can die. Make sure to bring them indoors if the weather becomes inhospitable for a long time.

Excessively rainy or humid weather also causes issues. Foremost, they will leave plants extremely vulnerable to fungus and mold, so try to make sure your plants get dry and warm after periods of cold rain.

Learn how to deal with cold, rainy and humid weather.

Of course, storms can also cause direct physical damage to your plants. There’s little you can do about this if you are growing your plants outdoors.

Overwatering and underwatering weed plants

When and how much to water your plants? This is practically an art. Your plants need change during different stages of development and depending on other environmental factors. You can’t let your plants go for too long without water, but if they don’t get enough, they will wilt and become unhealthy.

over watered cannabis

Don’t ever wait until the plants start to become limp before you water them. The easiest way to see if the plants are getting enough water is to check the substrate or soil the plant is growing in. It should be moist without being wet or saturated. If the soil is too dry, then water it.

Read more about when to water your cannabis plants.

Too much water can also cause issues for your plant. If the roots of the plant don’t get enough oxygen, the plant can drown. Make sure the soil around the roots is properly aerated, and that the plants drain well.

Soil problems with weed plants

Soil is the frame for your plant. If you’re growing outdoors, you can find a huge variety of different types of soil, depending on your location. Many places don’t have soil that is good to work with for growers, so check on the soil quality near you before starting up your growing operation.

Cannabis soil problems

Clay soils have poor drainage, for example, and this can cause your plants to drown from overwatering.

Sandy soils often drain too well, and the plants won’t get enough water or nutrients. Dried-out soil often needs to be treated, mixed up, and moistened for it to work well. All of these different issues can be fixed by adding different soil types into the mix and balancing out the environment.

Read more about the best soil for your marijuana plants.

Marijuana seeds with strong genetics are more resistant to common problems and diseases. Get my Plant Protector kit to protect your plants against all kinds of stress, pests and other issues!

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Marijuana plant stress FAQ

Can pruning cause stress to weed plants?

If you prune your plant excessively, it won’t be able to produce as much energy, and so it won’t produce as many buds in the long run, and those buds that are produced will be smaller. 

What’s the ideal marijuana growing temperature?

Ideally, you should keep the environment close to 80 degrees Fahrenheit, but it will do well near this as long as it isn’t too hot.

What should you do if your plant gets knocked over?

You should get the plant back into position as soon as possible and repair any of the breakings that might have damaged the stem.

Practice and learning are the key to growing marijuana like a pro. Get answers to your growing questions in my blog.

Have you experienced any of these stress-causing problems on your marijuana plants? Please feel free to share or leave questions in the comments!

Happy growing!


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Mr Robert Bergman PhD


Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations ... See profile

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40 comments on “Environmental issues that cause marijuana plants to stress”

  1. What is the best way to start seeds for outdoor growing.
    Should I soak them before placing them in the starting soil.

  2. Your site is invaluable! Kimberly the Dwarf Seed from a Hydro plant, look like wilted, her top wilted. Cold too out. She’s inside her room. Y say too
    Much Water. I Must Not give water only every 3 days? Or dirt is dry. She stil Green, & I give her cockroaches & monthly sardine. Thanks to U she may live, hopefully For Ever .

  3. I got gorilla glue bout a month ago.. I had 5 seeds that didn’t germinate…
    I’m leaning on your guarantee.

  4. I have a friend who will give me some seeds to germinate for myself. He just tell me the name of the seed. Gelato, Blue Dream, Head Band. Just to name a few I notice that they could be autos or phenos. I don’t start with LST. I start off toping all my plants. I know it’s wrong for a beginner and so forth I’m used to growing house plants and garden flowers Zinnias lButterfly and other plants that by pinching the tips encourage plants to spread. After doing so the new fan leaves will only have three (3) fingers or the leaves will grow in a spiral. I even grown 11 plants at one time . Only 4 made it to harvest. 4 turned out to be male, 3 stressed so bad that half of one side plant looked normal opposite side it was dwarf looking . I rotate the plants moved around . I do have plenty of lights ,games temp 74 – 80 18 on 6 off. Becouse of autos having no idea if they are by HST them Its really confusing . I had very successful with other strains. Durban Poison, Candy Kush, Blue Dreams, Headband. Gelato . I Have Wedding cake , Skittles I don’t know if I have autos or phenos. I don’t know what to do . No way to contact the person who gave me the seeds.

  5. This guide has been helpful in many ways for my outdoor saplings. Thank you so much. And on a side note, growing indoors or out (if in a pot) throw a dozen or more local worms in to help the soil. And I’ve heard of “Isolating” Male plants with a clear trash bag. Any truth to this? I want to get 1 female seeded for future use.

  6. I put my plants on the porch when it was 88 degrees and one burnt. today, it was low 70’s and MORE leaves burnt. I’ve never seen this before.

  7. Jay new grower, you say Dutch bucket. have to assume you mean Bato bucket.You can water once an hour or less depending on how much solution the plant uses. In flower when budding the plant will begin to use much more solution and that means you may use different schedules during different phases of the plants life cycle. Bato bucket are designed to allow you to monitor schedule. You should only run the pumps until solution starts to drain from bucket. This will change during grow. In the greenhosue we water for 1 minute and off for 40 minutes or an hour. It just changes and you have to take the time to monitor how much solution your plants are using and when. Good Luck. Love Bato buckets. Perhaps join our support forum and look me up. Peace

  8. Good morning, thank you for sending helpful information on growing. My setup is called dutch bucket setup. Wow so many things to be mindful of. Just when the ph/light/nuts/vpd/temp/wind power blowing on the ladies is all set and right, the humidity starts to climb above 50%. Just wanted to let you know my system and some of the things I think about during my grow. the information you provide has never steered in the wrong direction. I’m very thank full. Still waiting to be able to purchase your products in Canada. Currently buying from spain and it takes 1.5 to 2 months to get here if it makes it across the border at all. In closing 1 question… I have an auto water system setup and am looking for the perfect timing. currently water 3 times in 24 hr for 6mins each time. 8am,4pm,12am. Ideas??? more/less frequency more/less on time watering.
    I’m curious for your thoughts. stay green and sticky..

  9. Nice!

    I lol’ed at “knocked over plants”. That’s hilarious! I’m sure we’ve all experienced dropping something on our girls or knocking them down accidentally…or having a cat pee on one after the dog knocked the entire thing over. Too funny 😀

    I didn’t know you could simply remove the male pollen sacs from hermies & let them keep growing. That’s comforting. I stick to the K.I.S.S. method of growing: Keep It Simple, Stoner. That means only a few ingredients: soil, light, water & air for my plants. No fancy hydroponic systems or fertilizers. That’s when things get complicated & expensive. Of course I’m a noob & not a full-time stoner either. Just someone who smokes for my migraines & to stem boredom. With the advent of autoflowers, any idiot can grow lots of weed on their balcony or windowsill. And there’s tons of potent varieties nowadays–practically any Sativa, Indica or Hybrid you could want.

  10. We purchased the three variety package of big bad and need to Hayes and chocolope last February received the product everything germinated good after about the third set of leaves coming out two of the big Bud died. I grow outside in a greenhouse everything has gone good so far except for noticing that one of the Amnesia Haze has turned into a male I don’t think it’s hermaphrodite not quite sure but have pulled the plant. Now I’m down to 6 plants and won’t get the Harvest that I expected. I took photos of the plant if you would like to see them I can send them? Would like to purchase seeds again next year but at this rate of loss and that amount of price on seeds I don’t think I can afford to do that and gamble that way I may have to go to my local dispensaries and purchase clones that is real fun trying to get to roots to take to dirt. Would like to know your thoughts on this male plant turning like it did please contact me back through text message Yours Truly Steve.

  11. RR,

    Well RR, you need to download and read the Free grow bible offered on this site 🙂

    I also suggest you join out free support forum, in order to gain knowledge as fast as you can absorb it and comprehend moving to the next step.

    See you there. lw

  12. Diane,

    I am sure someone has dealt with this issue. Your 1st inclination was correct. So something about it. Look into shade cloth. Search for 6′ x 50′ bulk roll of shade cloth. 80% UV blockage. Should be easy to find.

    Other than that. It is possible that your plant could be slightly affected in a small way. Not sure how close lights are, or how bright this issue is.

  13. Ross,

    The best way to share pictures with our experts is through our support forum. A very friendly community with all kinds of cultivation knowledge. We have staff experts too. Hope to see you there. 🙂

  14. Thanks Andy.

    We appreciate that you have seen the progress our company has made. We look forward to your continued support 🙂

  15. Ask Ed,

    This topic was created some time ago. The only reason that you may get the idea that Robert was steering members to any particular vendor, is off base.

    All these articles are guidelines, as there is no one perfect method to grow Cannabis. That is part of the fun and mystique of this magical plant.

    If a grower follows the advice given here, that grower will succeed. If you have a better way; that is OK too. That is why we also provide a support forum. Maybe you should check it out.

    Happy growing! 🙂

  16. I been growing for over 20 years in side legally I started with grow light for veg growth. Now I use fluorescent light that are LED I bought at Home Depot it works fine cheaper then buy them at a hydroponic shop and for growing they do great. . I think the person that wrote this is just try to sell product for hydroponic places you will see big growth from fluorescent lights he’s full of it

  17. I will have to move several plants indoors soon to facilitate earlier budding, any suggestions on how to avoid what are now females turning to hermaphrodites? I need to see good pics of herms to identify them….thanks!

  18. I am concerned about outdoor sensor lights that come on at night near my outdoor grow area. Will this screw up my budding cycle? Am thinking about trying to block any light that might interfere. Has anyone else dealt with this issue?

  19. yea I got kush 10 and 20 skunk and 5 special k in which only 5 kusk none specia; k and 4 skunk actually tuck to grow and then 3 truned out to be male!!! and may I say the high $ special k none grew or anything else. hey and I can not help I am in fl were it is hot. but I guess it’s my fault for living here . if your plants cant tack the tell us…yea I thought they were all female seeds?

  20. I agree, you can certainly grow a plant to harvest but yield will be much smaller. Without saying whether you are soil or hydro its still safe to say if you get better lights you will see much more growth.

  21. Hi Robert. I’m in a confused state here. My plant has been growing since March and is now flowering and drooping. This is all new to me and I wish I could send you pictures so you can see for your self. Let me know if I can through email

  22. Rob, when i first signed up to this site it was, quite frankly a joke. Every article was obviously written by an author with very little experience with the motive of sales. Glad to see things have moved forwards. Good article. My tip of this month is that Ladybugs are coming out of their May/June hibernation so if you see any whilst out and about, take them home to put in your room to fend off the dreaded Red Spider mite. A saucer of lemonade will keep them fed.

  23. You will not see rapid or vigorous growth using fluorescent lights. You can grow successfully with that set up, but must temper your expectations of yield; Which will be small.

  24. been growing about a month,only have a few leaves,stemes are strong.i have tools to check water & humidity,seem right. i have two florisent lights,stays 77 degrees. about 4 inches from lights just don’t have a lot of groth. is that normal.growing indoors.

  25. Peter newbie,

    You will be just fine starting with that schedule. PLants only uptake the nutrients and/or water as they need it. The only thing you need to monitor is if the plants appear to be over-watered. I doubt that happens. However; I am giving this advice without knowing what type of system you are using, hydroponically.

  26. Your advice is very helpful for me as I’m learning to to grow like a pro and I’ve learned so much from you so far. I have a one month old auto white widow growing in a flower pot outside and the winter cold is coming with rain and im brainstorming to convert my closet into a grow room real fast without to many mistakes and stress on her any advice would be greatly appreciated. The seeds you sent me are of great quality as they germinated and broke open in seriously 24 hours and she looks healthy and strong and every day I notice new growth and I’m very satisfied with ILGM as my personal favorite to go for seeds. Great job Rob, from San Pedro , california with

  27. Hi Robert
    I’m going into full hydo an away soil an coco,what do you think about watering times 15 minutes on and 45 minutes off while the lights are on. Will this program work or is that too much water an nutes their medium is some in straight perlite an some in straight hydrocorn clay balls your feed back would be great.

    Newbie Pete