Common Problems to Look out for when Growing Cannabis

Is your plant not looking as healthy as it should? See if one of these common problems when growing cannabis is the culprit, and learn solutions for each issue.
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Cannabis might go by the moniker of “weed,” but that doesn’t mean it’s as resilient as the dandelions that pop up in the cracks of your walkway. If only we could be so lucky! Fortunately, your plant gives off clear signs when something is wrong, and when you know the right clues, you can make the necessary adjustments. Is your plant not looking as healthy as it should? Use this guide to see if one of the common problems when growing cannabis is the culprit, and learn solutions for each issue.

Common Problems to Look out for when Growing Cannabis


Sometimes, there is too much of a good thing. Overwatering is a common mistake growers make when they are eager to give a plant too much attention. This can cause problems for your plant because the root zone needs oxygen, which waterlogging makes scarce.


You might be overwatering your plant if:

  • There are drooping leaves
  • Growth rate is slowed
  • Leaves are yellowing
  • The soil is wet a few inches down
  • In extreme cases, your plant has root rot


Fortunately, the solutions for overwater are easy, and your plant should bounce back if you take action (or lack thereof) right away:

  • Let your soil dry out for a few days
  • Wait to water again until the soil is dry 1″ to 2″ down


Like overwatering, overfertilizing is often the result of giving your plant too much of a good thing. This is referred to as toxicity.


You might have overfertilized your plants if:

  • Your lower leaves are yellowing and wilting (called nutrient burn)
  • Seeing slow or no growth, especially with buds
  • Browned or blackened limp roots
  • In extreme cases, plant death


  • Stop any fertilizing treatments immediately
  • Wait until the soil is fairly dry, and flush your plant by giving it a large amount of water (about 2-3 times greater than the volume of your planter). Your plant should show signs of improvement within a few days.
  • In the future, err on the side of offering your plant too little nutrients and make adjustments if needed
  • Wait to fertilize plants until they are more mature, approximately 5″ to 6″ tall

Nutrient Deficiency

On the opposite side of overfertilizing, nutrient deficiency can also cause problems. Like all plants, cannabis needs macronutrients and micronutrients to thrive. The big three are nitrogen, phosphorus, and potassium, which are all needed in varying quantities during the different stages of cannabis plant growth.


When your plants are deficient in critical nutrients, you might notice:

  • Leaf growth slows, and leaves have brown spots (points to a phosphorus deficiency)
  • Older leaves turn yellow or brown, sometimes with burnt-looking edges (signs of a potassium deficiency)
  • Stunted growth and loss of leaves, starting with the lower leaves first, plus your plant will be paler in color than usual (possible nitrogen deficiency)


Root Rot

Root rot happens when you give your plant too much water without giving the soil the opportunity to dry. While root rot shares many symptoms with other possible issues, you should have a good clue it’s root rot if you were overwatering. It can also be caused by decaying plant matter and moving young roots too soon.


You might be dealing with root rot if:

  • Your plant has an overall weak or wilted appearance
  • Roots are giving off an unpleasant odor
  • Leaves have burnt-looking edges or brown spots
  • Leaves turn yellow, and old leaves are dying off


First, you’ll want to investigate the roots to verify you’re actually dealing with root rot and not another problem. Roots are supposed to be milky white and have a stringy appearance. If the roots are instead slimy, brown, and twisted, you’re dealing with root rot. Unfortunately, addressing root rot isn’t as easy as other, less-serious issues.

  • First, remove the plants from the soil, and run the roots gently under water
  • Remove all brown, mushy spots with sharp scissors
  • Replant in fresh soil within a few hours

Take the Guesswork out of Growing with Harvest Hero

Our innovative Enhanced Perlite Mix mix features a unique, proprietary blend of perlite, diatomaceous earth, and essential nutrients that help support the critical vegetative growth stage of your cannabis plants. NC State conducted testing to see how cannabis plants were impacted by this 3-in-1 mix. Harvest Hero Enhanced Perlite Mix resulted in improved soil conditions with an increase in:

  • Flower bud dry weight
  • Plant diameter
  • Phosphorous and potassium accumulation
  • CBD yields
  • Nitrogen accumulation
  • Plant height

Harvest Hero Enhanced Perlite Mix helps your plants get the nutrition they need to improve soil conditions, especially during critical vegetative growth weeks. Try Harvest Hero today and grow further!

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