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Can stress affect my cannabis seed run


Positive stress makes cannabis plants work harder for a desirable objective; negative stress is counterproductive for growing and flowering and, lastly, it could finish plant lives – when cannabis growing, it’s important to maximize the use of good stress and to minimize the introduction of bad stress.

positive and negative stress marijuana

Negative stress

Some plant stressing factors are counterproductive for growing because they inhibit the plant capacity from absorbing the light for proper photosynthesis dark and light stages, they limit the proper amount for leave transpiration, they increase the susceptibility to pest and disease attacks, and, potentially, they make the plants develop genetic abnormalities (hermaphroditism) – it’s important to know the causes and avoid them as much as possible.

Light stress

When flowering, cannabis plants are very susceptible to the stress of light-cycle interruptions – it’s fundamental to keep total darkness along the whole switching off of lights, as well as a constant light change, i.e., lights always get switched on and off at the same time.

When working during light switching-off cycle , just use a low-power green LED as a light source .


When indoor growing , heat tends to be a much more negative stressing factor for cannabis plants than cold, due to lamps heat .

When environmental conditions surpass 27-28 degrees , the plants start to modify their growing patterns to provide higher transpiration levels and keep the plant fresh – scarcely robust, branch ed structures (negative result in final production) .

At extremely high temperatures, photosynthesis can cease totally, so growth ripening would delay – it’s fundamental to keep room temperature and humidity at proper levels all day long for efficient growing and flowering .

Positive stress

Some types of stress can be positive for strain development – cannabis plants exposed to certain types of stress will provide robust plants which can produce higher resin amounts and bigger buds .

Air circulation

Air circulation in the room ’s the most common way to stress the plants – it could be said that every grower has a fan swinging his plants from side to side; with a swinging fan for strain movement, the plant stem gets little tensions which help it get thicker and more robust .

Trimming and tutors

Trimming’s useful for plant growing , manipulating the shape and size of the plant – these stress factors modify the growth when changing the distribution ways of plant nutrients, modulating the metabolic rates and physically expanding the plant sideways, so keeping a uniform canopy gets easier .

There are several ways to get it – some of them are kind of extreme, but it’s worthy to experiment with them if you haven’t done it yet .

Low-stress training (LST) deals with little constant force amounts to stimulate the growth of the branches of the plants in the direction chosen by the growers while the lower nodes get opened for a higher light intensity .

The appliance of this tension along the vegetative-growth stage will provide a growth of thick stems , producing additional capacities of nutrient and water supplying when flowering – this technique’s very good to increase plants efficiency , keeping, at the same time, the total height of the plant to the minimum ( SOG/SCROG grows are good examples) .

Trimming can be done several times throughout the vegetative stage to keep the desired height of the strains, or to shape them in a certain way – no trimming when flowering .

Cold temperature

At first sight, i t could be a bad idea to let cannabis plants get too cold – actually, it could be beneficial to let the room decrease the temperature at night during the last two flowering weeks, so the plants would produce an extra resin amount (more powerful, tastier strains) .

Some conclusions

As previously mentioned , stress can affect plants in many ways , good and bad – up to the grower to know how to profit positiveness and control the stressing factors which could be negative for the grow (if properly used, certain stress doses will help increase grow production, so try it on and on) .

“Feminized seeds run the risk of catastrophic failure”

Back in the 1980s, the landscape of cannabis growing was inevitably changed by the discovery of how to make feminized seeds. As every cannabis grower knows, only female cannabis plants produce flowers, while male plants are just used to make the pollen necessary for female plants to produce flowers with seeds. This groundbreaking discovery meant that every grower was sure that every seed they were planting, would produce consumable flowers. Even though this aspect surely advanced cannabis cultivation as a whole, its application to large-scale growing can be particularly tricky.

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“There is an old saying that goes: it seemed a good idea at the time,” Jason Talmage explains. “I learnt the hard way the pros and cons of feminized seeds. With all due respect, growers who promote them just don’t have enough experience with feminized seeds.”

Instability of feminized seeds
Jason further explains that feminized seeds do not offer stable genetics, which eventually means that they may develop hermaphroditism. “Feminized seeds are just unstable,” he says. “Therefore, if they get stressed and develop hermaphroditism, they might ruin the whole crop. This is an incredible danger for large scale operations. If a whole crop is made from feminized seeds and just one plant becomes a hermaphrodite, then you might have to throw away everything, resulting in an enormous loss, not only with regards to that specific crop, but also with regards to the logistics of the entire operation. Indeed, without proper cleaning after a seeded crop, it may take anywhere from weeks to months before it is safe to grow in again. To fix this, one could use fresh water to clean the room as it deactivates the pollen. On the other hand, another method would be to utilize a pH-balanced freshwater foliar spray every five days on plants themselves which would help to mitigate the problem if a crop goes to seed and the company cannot just start over a new planting.”

The importance of data collection
According to Jason, the only way to prevent this from happening is to have an R&D department that can develop stable genetics and then carry out tissue culture. “The other thing with feminized seeds is that you are never sure if the plant will be stable,” he says. “They are not like clones that are all the same, but each seed is an individual plant with specific characteristics. If you take a bunch of feminized seeds and do some stress tests, it might be that you never get a hermaphrodite. But, in the moment you plant them and maybe there is some light leaks in the greenhouse, for instance, then one plant might develop hermaphroditism. These sorts of issues might happen in greenhouses, especially with those infrastructures that are not properly sealed. For example, the blackout necessary to induce the flowering to cannabis plants can be very expensive, so some people just use plastic to cover the facility. Needless to say, the chance of getting light leaks that could stress the plants is incredibly high.”

At the same time, not only light leaks can cause stress to plants. “It can be everything, such as root aphids, heat stresses, nutrient deficiencies, pH fluctuations, overdefoliation or overwatering or underwatering. The problem is that signs (symptoms) don’t manifest for some of these issues until days or weeks after the original stressor which by then it is too late to prevent the plant stress. When symptoms manifest on the plants, growers will often look for something that went wrong in the previous couple of days as opposed to analyzing long term data to find the original stressor leading to inaccurate diagnoses. This also shines a spotlight on why intense and comprehensive data collection is critically important in all phases of the process.”

Better go for another route
“Thus, Jason concludes that it doesn’t make much sense for large cannabis companies to opt for feminized seeds. “Feminized seeds run the risk of catastrophic failure,” he says. “I have seen hermaphrodite crops that were still sellable too, but then you have to spend more time and money to inspect each and every single plant to see which one meets the quality standards. If a large company wants to be sure about the outcome of its cannabis crop, then it has to invest in an R&D department that can ensure stable genetics. Many companies nowadays are going for this, as the competitiveness of the market and the razor-thin profit margins do not allow growers to make mistakes.”

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Pros and Cons of High Stress Training Cannabis Plants

High stress techniques, the different types, pros and cons and top tips when it comes to H.S.T and Cannabis plants.

  • 1. What is h.s.t?
  • 1. a. Super cropping
  • 1. b. What to know about super cropping
  • 1. c. Mainlining
  • 1. d. What to know about mainlining
  • 2. Advantages of h.s.t
  • 3. Disadvantages of h.s.t
  • 4. Top tips for high stress training
  • 5. Hst and autoflowering cannabis plants
  • 6. In conclusion

As a grower learns more about growing Cannabis, they will come across two types of plant training. Low stress and high stress, which both have varied results, so In this article, we explain about H.S.T, how it is done, pros and cons associated, and our top tips.

1. What Is H.S.T?

High stress training is a way to manipulate the growth structure, vigor, and canopy of Cannabis plants. The hands-on methods used are classed as highly stressful to the plants, however, will structurally produce the strongest plants with an increase in growth hormone. This increase is thanks to the genetic markers within every cannabis plant. When you intentionally and carefully wound the plant (especially in certain areas of the plant growth), she will “freak out” and send all the help she can to the affected area. This can result in several potential benefits. From increases in the yield size, the potency (boosted levels of both THC and CBD), and the production of the frostiest buds you have ever seen – the possible pros of HST have been well documented over the past 2 decades or so.

When HST is performed correctly, it can also result in a short, more compact plant with perfectly spaced bud sites and an overall canopy that can be much easier to maintain in the long run. These techniques are considered to be intermediate to advanced methods, so if you are just starting out it may be best to leave this stuff for a few more cycles. Only after you have all the other factors dialed in, and have become familiar with LST (Low-Stress Training) should you start considering implementing HST into your crop.

Super Cropping

The way that high stress techniques such as super cropping affect the plants, is by causing a spurt in a repair-growth hormone. As the plants recover and begin to form hard wooden knuckles around the original break, the branch repairs itself causing the rest of the plant to become stronger.

What To Know About Super Cropping

• Snapping between internodes to break the inner cell walls.

• Growth repair hormones are distributed to fix the break.

• Recovery time of 3-5 days is required before the wooden knuckle forms.

• Growth structure and vigor are improved.

• Plants that have been super cropped will produce heavy yields.

This should be performed super carefully! You want to cautiously bend the stem or branch as close to 90 degrees as possible without actually snapping it. Once this has been done there is a high chance that the branch or stem will no longer be able to support itself, so you may need to add some tape to help secure it back in place.


Mainlining, for example, is another high stress technique, that involves letting plants grow to the fifth or sixth node, then stripping away everything apart from the top node. This high stress technique requires a much longer vegetative time, with the end goal of producing symmetrically grown branches.

What To Know About Mainlining

• A technique based on symmetry and plant pathways.

• Training the plants to grow evenly is key.

• An excellent way to keep a plant height low.

• Mainlining can produce enormous yields.

2. Advantages of H.S.T

Low stress and high stress training should only ever be applied during 18/6, or prior to plants showing preflowers when growing outdoors. There are many advantages to training Cannabis plants from seedling until they transition into bloom. High stress techniques such as super cropping cause Cannabis plants to grow with a strong thickness and develop hardwood side branches. Growth repair hormone is emitted throughout the plant causing enhanced production and resistance. The height of the canopy is also manipulated to remain at the same height as the plants were snapped. Super cropping is an excellent way to limit the vertical growth of the upper canopy, making this technique ideal for growers with limited head height.

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Mainlining requires much more work than a simple super cropping session, however, it has enormous advantages for those who can only grow a few small plants. There is a great deal of pruning that takes place during the vegetative phase, and it is necessary to tie the side branches down with a symmetrical system in mind.

3. Disadvantages of H.S.T

As the name suggests, H.S.T can be very stressful for Cannabis plants, and despite it being very rewarding when applied correctly, at the best time using the ideal cultivar, to the beginner grower there can be a world of potential dangers. If Cannabis plants are not given time to recover before being put through more high stress, then this can cause a stunt in growth and even cause parts to grow weak causing potential infection.

This will often occur due to inexperience and down to the grower not being familiar with recovery time. The downsides to super cropping plants may not be mature enough to squeeze and pop, which may result in an open wound that can become infected, or even for the growth above the internode to die.

4. Top Tips For High Stress Training

1. Always use clean and sterile tools when pruning your plants, and make sure you have clean hands when applying the super cropping techniques.

2. Give plants plenty of time to recover before performing H.S.T. You will see branches recover with a thick wooden knuckle, which will be an indication of the break is fully healed.

3. Never apply any high stress training once plants have entered the flowering stage. The combination of hormonal change and high stress levels may cause hermaphroditism to occur.

4. Training Cannabis plants takes time and lots of patience, and there should be a goal set in mind before you flower. Be prepared for long vegetative periods indoors if choosing to use H.S.T.

5. Mainlining is a great way to become really hands-on with your plants and to understand the importance of energy transfer.

5. HST and Autoflowering Cannabis Plants

Autoflowering cannabis plants are the newer kids on the block and are truly leading the pack in terms of genetic advancements in cannabis cultivation. But, they do come with a few limitations that are not present for photoperiod plants. These limitations are not necessarily downsides, but they do have an impact on the types of growing techniques that can and should be applied. Since autos have a shorter vegetative growth period (usually 3 -5 weeks), they simply do not have the same amount of time to bounce back from HST techniques.

Any stress the plant is placed under will result in a stunted period of growth and development. This is fine for photoperiod plants as you can simply leave them under 18/6 light for an extra week, but with autos, we do not have this luxury. In general, it is best to leave the HST techniques to the photoperiods, and stick to less invasive methods for your auto queens. LST methods like tying the canopy down, or using a screen for scrogging are totally fine. You can even do some light defoliation, and lollipopping the lower branches is totally fine. Just use restraint and make sure you do not go overboard, otherwise, you risk putting the plant under too much stress – which, for autos anyway, can actually have the reverse effect you’re looking for and decrease both yield size and potency.

6. In Conclusion

We recommended learning about low stress training before attempting H.S.T, as a way to become familiar with how versatile, tough and well adapted the cultivar being grown is. When choosing a strain to practice your newly discovered H.S.T techniques, remember to look for a strong and steady cultivar, such as Purple Lemonade. She is ready for a challenge and will respond well to a well-performed training.