In nature, plants tend to stretch in order to outgrow other plants and get more light to survive but indoors especially growing autoflowering plants stretching can be a bad thing. Most growers that are using day-neutral cannabis tend to have some kind of limitations like grow space or not enough light as well as ventilation. And if a plant stretches too much then these limitations become very obvious and you won’t be able to get as much dope as you expected.

What is stretching?

Cannabis stretching basically is the vertical growth of the plant and if it gets out of control the plant can stretch so much that it won’t be able to hold itself and will fall to the ground from its own weight.

Positive aspects of stretching

Some growers think that all stretching is bad for their autoflower plants but it is not entirely true. Any weed plant needs a bit of stretching in order to get more internodal distance in which to grow those dense buds and get them closer to the light in order to fully mature. Stretching also helps to control mold in the buds. Bud-sides are farther apart and the flowers are not so massive and dense which are the perfect conditions for mold and bud rot to occur. If autoflower plants wouldn’t stretch at all then it would become a dwarf plant and be one joint only plant that no grower wants, so a little stretching is a good thing.

Negative aspects of stretching

Although a little stretch will be good for your cannabis plant, too much stretch will cause more harm than good.  Autoflower cannabis growers usually grow in small places and stretched plants can get too tall and become a big problem so you always need to control how tall the plants get and not let them stretch too far and get burned by the heat of the lamp. Too stretched plants are also very weak because the stems of these stretched plants are very weak and can bend easily and even snap in two. Stretching will also lower your overall yield by 30% to 50% and the stretched buds won’t be so dense and mature.

How to avoid stretching?

Stretching in cannabis plants usually is a sign of too little light because the plants is stretching closer to the light source to get more lumens and be able to perform photosynthesis and grow.

The first step to avoiding stretching is to buy a strain that is compact and will grow dense buds and won’t stretch. These strains usually are some Ruderalis x Indica crosses and if you want your plants to stay small you should avoid Sativa crosses and unstable strains that can show their regular parent traits and not the necessary ruderalis short size traits. Some good choices like all the “Short Stuff” Strains, Fast bud #2, and other amazing autoflower strains you can find at our autoflower seed reviews category!

Second and the most important step to avoid stretching is to get proper light and get the plant close to the light so that it gets all the necessary amount and spectrum to grow to its full potential. Usually, growers use Metal Halide(MH) bulbs for the first part of the plants life and when the plants start showing sex then they switch to the High-Pressure Sodium(HPS) bulbs. If you are using Compact Fluorescent (CFL) bulbs, T5 fluorescent tubes or Light-emitting diodes(LED) then you need to get them as close to the plant as possible to avoid plant stretching and provide your autoflowers with all the light they need.

Another way to avoid stretching is to crank up the fans. If your cannabis plants will get a good breeze it will need to toughen itself in order to stay alive and not to snap or bend. The extra strength these plants gain will be compensated from the stretching and your plant will not stretch so much staying more compact and dense.

Densely packed plants can also encourage them to stretch in order to get better light and outgrow other competitors, so you shouldn’t pack autoflower plants too tight and you should allow them to get as much light as you can provide.

Another cause of too much stretching in your plants can be the temperature difference between the night and daylight cycles. If you have 4 hours of dark period and it gets really cold at that time then you should probably get a heater or just leave the lights on 24/7 because temperature stress can be a big factor for cannabis plant stretching.

How to fix stretched plants?

If your plants have already stretched too much and you don’t know what to do then these tips will help you.

First of all, you need to check your light and probably put it closer to the plant or even change the bulb to a more powerful one as your current light may supply less light than your plants need.

The second thing you can do is crank up your fans and install an oscillating fan if you haven’t got one yet but you should be cautious and start slow, switching it on for a half-hour every other hour or something like that. If you introduce a big wind to stretched plant it can easily fall over and die, so be easy on them.

Another way you can fix stretched plants is to LST (Low-Stress Training) them and help their horizontal growth by just bending them and letting other branches to get more light.

The last thing you can do if the plant has stretched too much and starts bending over is installing some kind of a support system.  The best way is to put a stick or something like that in the ground and use a brace or a simple hemp thread to tie the plant to this stick. If you tie your plant to a support stick then you have to be gentle and not tie it too tight because the plant’s stem will grow wider and the thread can damage it. Also, be careful when putting the stick in the ground as it can damage the roots so be careful and if possible get that stick as thin as possible.


  1. Stumbled on your webblog through Delicious. You already know I will be subscribing to your feed.

  2. I’m not very sure but I think the light schedule of the plant also has influence in the stretching as the plants “grow” during “night” cycle. So a plant that is on a 18/6 light cycle, will grow taller than a plant on 20/4 or 24/0.

    I’m keeping my autos quite short by placing the CFL very close (like 5 cm away), have a fan on the plants 24 hours and on a 20/4 light schedule. During the first 4 days the lights were on all day (24/0).

    • Yes light cycle can defiantly be a major factor in autoflower stretching but it is not true that continuous light schedule will produce less, as autoflowers produce energy trough photosynthesis and more light means more energy! So a dark period encouragest a plant to stretch not grow more!

  3. Light cycle definitely has an affect on the stretching, something else you should not do is, if your growing indoors and say your 30, or 40 days in, do not decide your going to place your plants outside because they WILL, not maybe, they will stretch on ya. I already made that mistake. Could not believe how much they stretched, thought it would be good for the plants and to some extent it was but major stretching.

  4. ؁؁ĐṜỮ₥⥣☝ƋẮƋẴ on

    can you start growing with less than 12 light like 10 light and 14 dark , or this will trigger the flowering from start???

    • I have grown is about those conditions at about 13 or 15 hours of dark and my autoflowers were not starting earlier then they should, I cant guarantee you that but from my experience they wont flower right from start but they might start some days earlier than if grown with 24 hours of light!
      But know that they will be considerably smaller than they should be because of that low light amount!

      • ؁؁ĐṜỮ₥⥣☝ƋẮƋẴ on

        thank for the fast reply, but did you do it in or outdoor..? and what sterns of the auto you grow …?

        • that was an experiment on a windowsill growing the Fast Bud #2 strain and basically I started in late autumn so there were low light levels..

  5. Aaron 420 on

    Try and space your plants if possible. And the fan technique does work. I use it myself. I made a mistake and started critical mass autos then 3 white widows reg and s30 days in started 4 more assorted autos so have to wait for 8 autos to finish before i can flower the 3 white widows. I put them in 7 gallon pots . 100% TLO grow with compost tea. Organic bud

  6. diskokobaja on

    I have singke cob light,and my seedling got stretched a lot, but after few days , they continued to develop normal.. what should I do? throw them away or take my chances?

  7. Auto-man-grower on

    I have only grown autoflower cannabis plants and I have found at when plants are young start bending the top part of your plant down as far as you can get it so you get a even canopy you get more yeild and hey that’s what every one wants feed veg nutes to week 6 after week 6 start bloom nutes feed bloom feed to week 11 than flush I have grown a lot of strains all have taken 11 weeks + I would say 12 to 13 weeks if you want the most from your auto someone said somethink to me when I first started growing when you think it done leave it another week this has worked for me the last coulpe of weeks is when autos put most of they weight on but always look at tricones so super autos theses days can take 100 plus days so if you want the most from your autos grow for 12 weeks leaving your autos for a coulpe more week you should get at least 2 oz I get 3 to 4 oz from 1 plant sometimes more and one more thing as I said I have grown a lot of autos so I am writhing this from experience Dutch passion autos are great you can get 200 grams a plant if grown in good conditions I hope this has help people out who have never grown autos some auto theses days are nearly as strong as normal cannabis plants and some can grow big over 150 cms if anyone needs any advice growing autos email me and I will be more than happy to give advice my email is

  8. Hi there all.. I am a new grower and I was given some seeds as I spend far to much. I dont know what strain they are but I germinated them and they have started sprouting but 2 weeks in they seem to be tall like 2 the 4 inches.. is this to tall.. how do you know they are stretching? At the moment they have light from 10am till about 7PM and then dark from 7PM till 10am.. any advice will be great. Thanks.

    • RJ Boston on

      You only give them 9 hours of light?? You should be giving them 20 hours of light/sun then 4 hours of darkness. I’m guessing you said 2-4 inches? It all depends on the strain, but 2-4 is a big difference lol which is it, 2, 3, or 4 inches?

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