When you have marijuana plants with stretching stems, this can be an issue both indoors and outdoors.

There are several reasons why marijuana plants may stretch. Apparently, genetics play is a major role in this. Sometimes there is nothing you can do and the plant will create tall stems regardless of your efforts to stop it. One example of a strain that grows tall both indoors and outdoors is tropical and land race pure Sativa. However, you do have options for ways to reduce stem height between the leaves.

Why is stem stretching an issue

Why is stem stretching an issue

When growing indoors, stretching may seriously lessen your yields because of the challenges with imitation lighting. This may also create very weak stems, which means the plant is at risk of falling over. It is also definitely an issue where ceiling height is a concern.

Ways to reduce stretching

Ways to reduce cannabis seedling stretching

Air Circulation
Having good air circulation will allow the stems and leaves to get thicker and stronger while at the same time reducing how high it grows.

Strong air circulation can create stem and leaf movement that strengthens and widens the stem while also slowing its vertical growth. Winds will bend the stem, creating small rips in the plant’s tissue. You can also just brush the leaves to simulate the effects of air circulation.

Light Spectrum
The type of light you use also plays a role in how tall your stems will grow. Orange and red lights provoke taller, thin stems, but thick, short stems blue light is best. Using metal halide lamps while the plant is in the vegetative stage will produce short stems.

Another way to control the height of your plant is by using infrared light. You use these when the lights are off. There is a black cloth that covers the heat lamp reflector, which makes it so the infrared rays create the right results. At the same time, it catches red light to prevent contradicting what you are trying to accomplish. It is best to only use this light during the flowering stage.

Heat and Stem Growth
The temperature influences how your stems grow. The higher the temperature, the longer the stems will grow. Your plant’s stems will widen and the growth will lessen at about 60*F. When you have it around 80*F, the stems and buds will begin stretching.

If your buds get too close to the light, this causes it to become tall and thin. Don’t make the mistake of thinking this is light burn because this is not the case. In fact, the heat from the lamps can make it unbearable for buds. Air-cooled lamps are great for keeping much of the heat from coming into the room.

Not having the proper amount of light will lead to stem stretching. As a result, the seedlings will grow tall, thin stems because it is trying to access more light. As a solution to this problem, give it a more intense light schedule or you can place them nearer to the light. Once you have done this, the stems will grow thicker and do much better on their own.

Lastly, try pruning as a way to reduce stem stretching. By cutting off the top of the stem, it makes the rest of the branch grow.

Spacing In-between Plants
Growing your plants in bulk leads stretching. As your plant grows, the leaves may easily start coinciding with the plant next to it. Over time, this causes the bottom of the plant to be discolored and the sub-canopy will get darker.

Reduce Stress
Stem stretching is the result of many factors, which include high/low temperatures, transplant shock, light spectrums and humidity. Keep your plant happy by making sure the environment is the best for your plant.

Tips for stem stretching

Tips for cannabis seedling stem stretching

There are times when some growers like a bit of stretch since this is good for avoiding bud rot in certain strains. But in most cases stem stretching is not desirable.

During the vegetative state and the first two weeks of the flowering stage use blue lights to reduce stretching. If your plant is stretching, refrain from giving it too much nitrogen. Instead use a fertilizer ratio of (2-2-2) at the beginning of the flowering stage to keep the nitrogen levels average. Making an instant shift to the normal flowering ration right after the vegetative stage causes yellowing. Lastly, remember to use oscillating fans to help make your stems healthier.

Remember that plants with strong genetics have less change of getting sick and are less vulnerable for diseases, deficiency’s, pest and environmental stresses. So make sure to buy marijuana seeds from a trusted seed bank.

Thanks for reading. Please leave comments or questions below and don’t forget to download my free grow bible

Robert

60 Comments

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  1. By Jon

    ,24 Jul 2014
    What is the difference between indoor and out door seeds? Does it really matter one way or the other?
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    1. By Budzila

      ,03 Jan 2016
      BUDZILA here when is it a good time to start germination my seeds and the best-known way to due so please.
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      1. By Paul

        ,19 Aug 2017
        Hey Rob my plants are 22 days old.white widow fems.there only about only 10″ tall but are very health . I got them on 18 hrs. On. It worrys me does this seem normal . We do smoke mar
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    2. By Snoleperd

      ,18 Aug 2017
      I have a little trick, works every time, take the paper off a bread tie so you are left with the wire, shape the wire so it’s vertical stic the wire in the soil at an angle away from the […]Read More
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  2. By David 1954

    ,05 Jun 2015
    Hi, Great reading well explained. Thanks.
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  3. By Increase Your Marijuana Yield – 5 Tips

    ,20 Jul 2015
    […] are in their vegetative phase and are not receiving a high enough intensity of light, they will “stretch” upwards toward the source of light. This can lead to large spaces on the stem between nodes and […]
    Was this comment helpful to you?
  4. By Symptom Checker – Identify Marijuana Plant Problems

    ,24 Jul 2015
    […] Stretching plants […]
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  5. By Seedling Stage For Marijuana Plants

    ,18 Aug 2015
    […] Other solutions to this problem include using an excess of blue light, maintaining temperatures at around 80*F, or making sure that plants have all the light they need available to them. If light is scarce, the plants will start […]Read More
    Was this comment helpful to you?
  6. By Problems That Cause Marijuana Plants To Stress

    ,18 Nov 2015
    […] 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 […]Read More
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  7. By pat

    ,30 Dec 2015
    Can you say the reasions y one plant turnes male and the rest are fine this is at the start and the serds are femanised regards pat
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  8. By Brian

    ,30 Dec 2015
    I usually use a single t5 grow light for my seedlings until they get about 5 or 6 inches tall. Is this OK? I bought a 4′ 4 light t5 also for when they grow bigger then switch to a […]Read More
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  9. By Stephan

    ,30 Dec 2015
    I would like to get ur bible book , not a email! I don’t know if it’s possible? If it is 154E County Rd 14 Cottam,Ontario,Canada N0R1B0 And I thanks u for all the help u gave me so far!!!
    Was this comment helpful to you?
    1. By Jennifer ILGM

      ,03 Jan 2016
      Hi Stephan, Unfortunately the Bible is only available in as an e-book and not in hard copy.
      Was this comment helpful to you?
    2. By BrianK

      ,10 Jan 2016
      just print it out and put in a binder, that might help =)
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    3. By AKConiferious

      ,18 Aug 2017
      so get a printer, a 3 ring binder, and a triple hole punch…
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  10. By ruven golan

    ,30 Dec 2015
    Please anyone have recommendations for supporting weak elongated stems? Is supporting by elevating the soil around the stem OK?
    Was this comment helpful to you?
    1. By Jean

      ,31 Dec 2015
      @Ruven, probably not. You can do that for things like tomato seedlings, because all of those little “hairs” on the stem can turn into roots if they’re covered with soil. I don’t know that cannabis has that ability, and so […]Read More
      Was this comment helpful to you?
      1. By Richard

        ,31 Dec 2015
        Tomatoes do produce adventitious roots almost anywhere along the stem. They aren’t associated with the “hairs” you can see but the bumps that form from the base up the stem. In fact, when I transplant tomatoes, I lay the plant […]Read More
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        1. By Jennifer ILGM

          ,03 Jan 2016
          Hi Richard, check out this article: http://www.ilovegrowingmarijuana.com/how-to-make-marijuana-clones/
          Was this comment helpful to you?
      2. By Bob Smith

        ,28 Feb 2016
        Say there Ruven: I use bamboo stakes and narrow green tape and tie them loosely. The tape is available in most grow stores. Also there is a product called “Silca” Several companies make this and it works to build stronger […]Read More
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    2. By Art

      ,17 May 2016
      Tie to 3,4 or 5′ stakes. Bought at any grow shop. If you need shorter stakes cut to size
      Was this comment helpful to you?
    3. By Veronique

      ,20 Aug 2017
      Yes I bury them up to their necks in a larger pot mist w aloe and unsulhphered molasses
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  11. By Jean

    ,31 Dec 2015
    “Not having the proper amount of light will lead to stem stretching. As a result, the seedlings will grow tall, thin stems because it is trying to access more light. As a solution to this problem, give it a more […]Read More
    Was this comment helpful to you?
    1. By Lucinda

      ,31 Dec 2015
      I treat mine like tomatoes and if they stretch I bury them deeper just like a tomato plant, but only in the seedling stage. Mine always do well and have more roots because I plant them deeper to cover the […]Read More
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  12. By Richard

    ,31 Dec 2015
    Robert, A quibble and a question about light: There have been two changes in the way artificial light is designated. Lumens has replace watts as we’ve moved away from incandescent lamps. And with the advent of tuned LED’s “degrees Kelvin” […]Read More
    Was this comment helpful to you?
    1. By JJ northern

      ,17 Aug 2017
      LED. for veg and flower. I say LEDs for veg. Not flower…
      Was this comment helpful to you?
  13. By latewood.ILGM

    ,04 Jan 2016
    Richard, We still measure lighting in watts and lumens. What has happened is that the LED industry is so Non-Standardized, that it actually takes buying and experimenting with the different brands in order to realize at what values they function. […]Read More
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    1. By Bob potter

      ,05 Jun 2017
      I just done a crop.of mazars and sugerhaze in nft under 2 marrshydro 48s cost me 82 pounds each got 12.onces of top drawer dryer cured bud best crop I be ever had this is in a 80 x 80 […]Read More
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  14. By darryl

    ,05 Jan 2016
    to growers, i used led 200 watt for seedlings, but my light is about half way of my tent due to plant stretching and it works for me, once i start on my forth nod i throw them into a […]Read More
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  15. By Marijuana Plants Too Hot « HempNEWS TV

    ,10 Feb 2016
    […] How To Deal With Stretching Marijuana Plants? – Stretching marijuana plants? Lack of light, wrong light spectrum or strong wind cirulation are some of the reasons marijuana seeldings stretch. To avoid your […]
    Was this comment helpful to you?
  16. By Itsme

    ,29 Sep 2016
    Side by side plants in 5L pots using the same soil and sharing a 1.5m LED grow strip light. One plant shot up and the other stayed short and bushed out?? Had to raise one end of the strip light […]Read More
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  17. By Eric Bowers

    ,30 Sep 2016
    The solutions only cover indoor grows. When growing outdoors, someone want to explai how to get it closer to the light? Lol. But would be great info if I was growing indoors.
    Was this comment helpful to you?
  18. By latewood.ILGM

    ,03 Oct 2016
    Put it on a Large pedestal!? LOLI guess it is too bad you are not growing indoors, LOL.
    Was this comment helpful to you?
    1. By Itsme

      ,18 Aug 2017
      Like your humor. I would have said ladder.
      Was this comment helpful to you?
  19. By How to Increase Your Marijuana Yield – TheJointBlog

    ,27 Oct 2016
    […] are in their vegetative phase and are not receiving a high enough intensity of light, they will “stretch” upwards toward the source of light. This can lead to large spaces on the stem between nodes and […]
    Was this comment helpful to you?
  20. By Darren Kirk

    ,04 Dec 2016
    Ive just stated to grow,and ive got 2little seedlings,I only have a 400w bulb so I have been putting it on for 2hours a time to heat my little cupboard then I put it off.I do this 3times a day […]Read More
    Was this comment helpful to you?
  21. By latewood.ILGM

    ,05 Dec 2016
    Darren Kirk, I do not understand why you are only running light 2 houes… Light should be on 14-18 hrs per day, and off the rest. Stretching is due to plants reaching for light. Best way to prevent stretching is […]Read More
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  22. By j cameron

    ,14 Jan 2017
    best compost for growing plants indoors
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  23. By Steff

    ,26 Jun 2017
    Thanks for this info
    Was this comment helpful to you?
  24. By Julie Whitton

    ,26 Jun 2017
    Thanks for this info
    Was this comment helpful to you?
  25. By elizabeth

    ,22 Jul 2017
    hi Robert please will you email me i need a little advise. now as ive spoent so much money and now on second set of seeds, they ate 6 days old but thin and tall stems. i have a tent […]Read More
    Was this comment helpful to you?
    1. By Roy ILGM

      ,24 Jul 2017
      Hi Elizabeth, best hop onto our support forum. Our experts there can help you with all your questions.
      Was this comment helpful to you?
  26. By Tim

    ,18 Aug 2017
    I grew old Mexican weed for years. Seedy but good. The new hybrids are way better but you’ve got to try way harder.
    Was this comment helpful to you?
  27. By Clay Scott Brown

    ,18 Aug 2017
    The plant should even out in some way… it is difficult and somehow different to use the High Powered Light on the seeds these days… considering the Hydroponic Arena where vast farms of it are grown with Amazing Root and […]Read More
    Was this comment helpful to you?
  28. By Davoid

    ,18 Aug 2017
    What time of the day is best to feed my outdoor plants?
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    1. By latewood_ILGM

      ,18 Aug 2017
      David, You always feed your outdoor plants as soon as the Sun comes up. 🙂
      Was this comment helpful to you?
  29. By It’s me

    ,18 Aug 2017
    I started an indoor grow with 40 plants. They took off like bottle rockets, grew 10cm in a couple days – really tall and skinny then started falling over even tho I had a fan blowing on them and white […]Read More
    Was this comment helpful to you?
    1. By latewood_ILGM

      ,18 Aug 2017
      It’s me, Seedlings stretch out due to inadequate light. Invest in some T5 lighting and keep it 2″ above your babies. I think you will like the result.
      Was this comment helpful to you?
  30. By russ hochman

    ,11 Feb 2018
    hello everybody—– i,ve done my re-search & still the same 🙁 streaching-stem,s under 1,600 lum,s of cfl, & happy-frog, ( the best of both-world,s ) ( from lite,n,soil ) whats a worried-man to do, im russ, i know-i know, but […]Read More
    Was this comment helpful to you?
    1. By latewood_ILGM

      ,16 Feb 2018
      russ hochman, First thing to do is lose the CFL. Invest in a 4 tube T5 lamp and put it 1.5″ from the sprout and monitor and adjust as needed to keep lamp 1-2″ from seedlings. This will stack the […]Read More
      Was this comment helpful to you?
  31. By latewood_ILGM

    ,16 Feb 2018
    russ hochman, BTW, 1600 lumens is very little.
    Was this comment helpful to you?
  32. By russ hochman

    ,22 Feb 2018
    latewood_ilgm, —-im on a buget, cfl is all that is around & cheap, you didnt say anything about my soil, so im guessing frog-dirt is good, steem,s are wiked-turn,s & 2nd & 3rd leaves comeing but awfull steem,s, im lost […]Read More
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  33. By latewood_ILGM

    ,27 Feb 2018
    Join here!: support.ilovegrowingmarijuana.com Leaving a Red light on 24/7 is totally off base. I suggest you take me up on my offer and join our forum. It sounds like you are loving them to death 😉 Happy frog is OK […]Read More
    Was this comment helpful to you?
  34. By russ hochman

    ,28 Feb 2018
    allwrighty-then & 10-4 gottcha-ya
    Was this comment helpful to you?
    1. By latewood_ILGM

      ,18 Apr 2018
      Russ, I hope to see you in the forum. Perhaps you already got help. There are so many options for you that it is hard to discuss it all here in the blog. IN the forum; When you post; Place […]Read More
      Was this comment helpful to you?
  35. By Tombstone

    ,15 Sep 2018
    New at this. In the 70,so it was easy. First grow and all 5 stretch Ed and baby sitting the last one using the tips here. My question is my next order, what strain is best for THC for extreme […]Read More
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  36. By latewood_ILGM

    ,25 Sep 2018
    Tombstone, I recommend you try Robert’s Gold Leaf. This is out signature strain, high in THC and CBD. An excellent grower with good yield and a favorite among members at ILGM 🙂 Happy growing
    Was this comment helpful to you?
  37. By Edward

    ,11 Feb 2019
    Thank you for the response. This is actually my third grow. I was just wondering if this common for the strain. Blackberry Kush. I actually have nine plants going out of the ten seeds that I germinated. Not too bad
    Was this comment helpful to you?

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