Copper deficiency in marijuana plants

If your marijuana plant has a copper deficiency, this means simply that it doesn’t receive enough copper. This could be due to a lack of copper in its nutrients or something stopping it from accessing the normal amounts of nutrients.

Copper toxicity is when the plant has too much copper. This also means it is unable to use iron (Fe).

Signs of a copper deficiency on cannabis

While copper deficiencies don’t occur very often, they can make a major impact on your crop when they do happen. You will first see it cropping up on the younger leaves, which will start to become discolored on their tips and margins.

They will have an odd, metallic glint to them of a copper-gray or blue-ish color. The flesh between the veins, however, will start turning yellow.

You might also notice curling or wilting of the leaves, which will eventually turn into complete leaf death. Although just seen in a few leaves at first, it could lead to a full wilting of the plant.

You will notice your plant having trouble with new growth, and the flowers in male marijuana plants won’t mature properly while females’ stigmas will exhibit abnormal growth.

With copper toxicity, on the other hand, the leaves will simply start to yellow, your plant’s roots will grow unnaturally large, and they will start decaying. This comes from your plant’s inability to utilize iron (Fe).

If you want to make sure that you give you plants the highest chance on getting the proper nutrients, or to prevent nutrient issues in in the first place, I have created a perfectly balanced fertilizer kit, ready to use for all marijuana plants!

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Bergman’s fertilizer kit

  • Enough nutrients for at least 5 plants
  • All the nutrients from seedling to harvest
  • Usable for all marijuana plants
  • Suitable for soil, hydroponic and other growing mediums

Not sure if your plants have a copper deficiency?

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

How to fix a copper deficiency

The first thing you should do if you think your plants may have a copper deficiency is to flush out everything with pH-balanced water that contain a mixture of nutrients. The pH level is extremely important. If your growing marijuana in soil, copper will be absorbed by your plant the best if it is at a pH level of between 6.0 and 7.0. In hydroponics systems, try going to a pH range between 5.5 and 6.0 instead.

To make sure that a copper deficiency or surplus doesn’t devastate your plants, you could try a product like Marijuana Booster to make sure your plants get a balanced serving of all the nutrients they need.

How to fix copper deficiency cannabis
Signs of copper deficiency

Another way of dealing with copper deficiency is to feed the foliage with copper fungicides. Copper fungicides include copper sulfate and chelated copper. Other natural substances that can help with copper deficiencies are greensand, kelp, and compost.

A more surprising option you might want to look into is actually soaking dimes or quarters in water, then feeding the plants with this water. This is because dimes and quarters are made up of almost all copper – 92%!

Don’t fret if the old abnormal growths don’t recover – new growths will form and will be healthy if you got rid of the copper deficiency problem.

Using the correct nutrients and plant protector will get you a long way and your plants will have less chance of getting sick, in addition of being less vulnerable for pests and diseases. I have created multiple grow sets which features all you need in order to grow healthy plants from seed to harvest!

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Buy your grow set

List of marijuana plant symptoms

You can recognize a plant that has a copper deficiency differently, depending on whether the leaves are old or young. In younger leaves, the following symptoms may be exhibited:

Leaf color

  • Darkened, twisted leaves
  • Undertones of blue and/or purple
  • Metallic glinting

Leaf symptoms

  • Leaves curling under
  • Tips that are turning yellow or white

In older leaves, on the other hand, you may instead see pale yellowing or the leaves turning white. Other symptoms you might see on the plant are:

Leaf symptoms

  • New growths have trouble beginning to grow

Plant symptoms

  • Lack of ripening in the buds or growth is very slow
  • The female pistils are not growing regularly
  • Limp, wilting plant and/or leaves
  • General growth abnormalities
  • Weakened stems
  • Slow, twisted, or curling growing patterns

Almost all soil and water have a certain amount of copper at a minimum, so it is quite rare that the deficiency comes from there. Instead, the issue most likely stems from a pH problem. When the pH isn’t balanced, your plants lose some of their ability to access nutrients.

Copper deficiency marijuana plant
Copper deficiency marijuana plant

Copper toxicity is also rare, but not to be ignored. If your plant receives too much copper, it could die very quickly. Make sure you are proactive when you suspect a copper problem!

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


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Mr Robert Bergman PhD


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

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14 comments on “Copper deficiency in marijuana plants”

  1. i have seedling witchin week 1.5 and the larger leaves are starting to turn waves of yellow could it boron ?

  2. Misspelling at end of article; Remember that plants with strong genetics have less change of getting sick. – change or chance?

  3. gettoplumber,

    Copper oxidizes. I do not want chemical changes going on in my soil Why do you think they soaked it?

    If you really want support for your grow; Join our support forum. There you can post a pik. This is a blog and not meant for ongoing grow support. We have many helpful members in the forum and grow experts too. 🙂

  4. Mr Latewood,
    you stated not to use real copper wire, why not?, if I left them in for about a week and then pulled them out would that be enough for the plants to absorb? I would post a pic but not sure how to do this here. this way you could see what is going on
    thank you for your advise!!!

  5. Mr. Latewood,
    Chelated copper? haven’t heard of that, lol and i’m a plumber, it says to soak quarters and or dimes but for how long, and how much, and is one app enough?
    Please elaborate on this Chelated copper Please, where to get it, how much to use ,and for how long, how often?

  6. gettoplumber,

    I would not advise putting Copper wire in your soil.

    I use chelated Copper to deal with Copper deficiencies but, I have never had this happen. You only need a tiny bit.

  7. this says to fix copper deficiencies by soaking quarters and or dimes in water, but for how long and can you put copper wire in the soil with the plants will do the same thing?

  8. hi! i am at the job atm so i did not have time to read all of the article, hevweor i do enjoy the stuff i read and i will read a little more at your web site when i get home.. I got a a bounch of stuff to finish at work do you happen to have a username on facebook? =) Thank you, Resor Till Los AngelesVA:F [1.9.17_1161]please wait…