Sulfur deficiency in marijuana plants

Sulfur deficiencies in marijuana plants are quite rare. This is a good thing because good growing roots, the proper amount of chlorophyll, and the development of plant proteins are all processes aided by sulfur throughout the vegetation stage.

This deficiency is first noticeable when it causes newer leaves to yellow and in some cases the leaves may become orange or red. It may even resemble a nitrogen deficiency.

Download my free marijuana grow bible to know more about sulfur deficiency and other nutrient problems.

Signs of a sulfur deficiency

When the leaves begin to slim and get fragile, the plant’s growth will slow down. In contrast, the leaves will also be smaller.

When in the flowering stage the buds begin to die off and the whole plants growth may slow down.

Signs of sulfur deficiency marijuana plant
Signs of a sulfur deficiency marijuana plant

If the issue is serious, the veins of the plant may become yellow and the damaging parts will most likely show up at the bottom of the leaf.

The slim, woody stems will continue growing taller but will not expand.

Having too much sulfur will reduce the size of your plant and cause the leaves to look dead and brown on the tips.

Too much sulfur has the same damaging effect as salt with reduced growth and dark colors.

Not sure if your plants have a sulfur deficiency?

Also read the article Nutrient deficiencies in marijuana plants for a list with pictures of all deficiencies.

How to fix a sulfur deficiency

The simplest way to cure a sulfur deficiency is by using Epsom salts (wiki). All you have to do is water the plant with Epsom salts and wait until it gets better. Use one, maybe two teaspoons of Epsom salts per gallon of water. If you have any other nutrients that have sulfur in it, feel free to add that as well. A good water-soluble fertilizer that contains sulfur will work just fine.

Sulfur deficiency cannabis plant
Sulfur deficiency cannabis plant
Here are some other choices:
  • Elemental garden sulfur
  • Gypsum
  • Potassium sulfate

Never put gypsum on soil that has a pH lower than 5.5. It can create an environment that is toxic to the plants.

Give your weed plants a little extra love. Our marijuana fertilizer set has the perfect mix of nutrients to provide the greatest yields.

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Last but not least, check and fix your pH levels to ensure the sulfur isn’t getting blocked out.

Sulfur travels at a slow pace throughout the plant so it could be a few days once the issue is resolved before you will see that things are getting better for your plant.

Also read the article Check pH of soil or Check pH of hydro for more information.

List of marijuana plant symptoms

Leaf color:

  • Pale color leaves
  • Yellow leaves on new growth
  • Yellow leaves on lower leaves
  • Yellowing between veins
  • Red or pink color on leaves

Leaf symptoms:

  • Upper leaves and newer growth damaged
  • Lower leaves and older growth damaged
  • Yellowing between veins
  • Reduced growth

Plant symptoms:

  • Limited growth

Other symptoms:

  • Buds not thickening

Luckily, sulfur deficiencies are very uncommon. You are less likely to have to go through the trouble of repairing this issue.

Sulphur Defficiencies On Marijuana Plants

To ensure your plant stays deficiency-free, do your best to feed it a balancing meal of all the proper nutrients it needs.

Monitor your plant frequently and if any signs of deficiency pop up, just follow the suggestions listed and you will be just fine.

Grow weed plants with strong genetics to lessen the risk of dealing with plant diseases. Luckily we have an all-in-one care package for you: Bergman’s Complete Grow sets!

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FAQs about sulfur deficiency on weed

What are some symptoms of cannabis sulfur deficiency?

If you notice pale, yellow or red/pink leaves, reduced growth and buds not thickening, your plant most likely has sulfur problems.

How can you treat sulfur deficiency on marijuana plants?

Among some ways to treat sulfur problems on weed is to use Epsom salts, elemental garden sulfur, gypsum or potassium sulfate. You can also try our Marijuana fertilizer to give your cannabis plants the right mix of nutrients that it needs to thrive.

Have you dealt with sulfur deficiency on your cannabis plants? Please leave comments or questions below.

Happy growing!


Avatar for Robert Bergman

Robert Bergman


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

8 comments on “Sulfur deficiency in marijuana plants”

  1. My leaves are starting to go yellow and curl in the way,I have forgot to give calmag 3 feeds sin a row now I flushed them and PhD the water the run of was all between 6.71 and 6.81 and that was 6 plants,another have had a good flush and they are still the same with the yellowing amnon 2nd grow so I dont have a clue

    • Jordan. Gypsum is the least recommended remedy. If you still want to use Gypsum, then I recommend finding a source and following directions on the bag.

      You would be better off using Epsom salts, or sulfate of potash, or another nutrient blend as recommended above in the article.

      Perhaps joining our forum would suit you better. Go here

  2. I am currently waiting for my order of Marijuana Booster to arrive. My question is about the water I mix it with . I have a chlorine scrubber to remove the chlorine from my tap water. DOES MARIJUANA BOOSTER adjust the Waters PH for growing indoors in soil OR should I find a way to test and if needed adjust my waters PH & if so what is the recommend PH for my water when I am using your Marijuana Booster ???