zinc deficiency cannabis

Zinc Deficiency

Problem: With a cannabis zinc deficiency, younger leaves start yellowing in between the veins. Leaf tips get discolored and start dying. the leaves may take on a unique banded appearance and the plant may stop growing vertically. There may be much less space between new nodes, which can cause new leaves to start bunching together. If the plant is budding, its flowers may stop growing or even start dying if the problem isn’t corrected.

Solution For Cannabis Zinc Deficiency

Note: Sometimes a cannabis zinc deficiency (like all deficiencies) can be triggered by stressful conditions and may clear up on its own after the period of stress is over. However, to minimize damage it’s important to react to any growing problem as quickly as possible, especially in the flowering stage.

1.) Adjust pH to Correct Range

The most common reason growers will see a zinc deficiency is when the pH at the roots is too high. Zinc tends to get locked at higher pH levels and is better absorbed by the plant in a more acidic root environment.

If you suspect your growing cannabis plant has a zinc deficiency due to too-high pH, flush your system with clean, pH’d water. This will remove any nutrient salts that may be affecting the uptake of zinc and help restore pH to the proper levels.

  • In soil, zinc is best absorbed by the roots in the 6.0 – 6.5 pH range (although it’s generally recommended for soil growers to keep pH in the 6.0-7.0 range, zinc tends to be absorbed better on the lower side)
  • In hydro, zinc is best absorbed by the roots in the 5.5 – 6.0 pH range (although it’s generally recommended for hydro growers to keep pH in the 5.5-6.5 range, zinc tends to be absorbed better on the lower side)

2.) Give the Right Nutrients

The truth is, most cannabis growers don’t need to add more zinc in response to a zinc deficiency!

In fact, most growers have actually already given plenty of zinc to their cannabis plants since it is found abundantly in most tap water. If you’re using quality soil or cannabis-friendly nutrients, you probably don’t need to worry about adding more zinc. In general, zinc deficiencies are more likely to appear when a grower is using heavily filtered or reverse osmosis (RO) water to feed plants since any zinc has been removed, but pH is a much more common reason growers see zinc deficiencies in their cannabis plants.

3.) Take Good Care of the Roots

Zinc deficiencies can show up with the plant is having root problems or if the plant is overwatered, even if the pH is right and the zinc is there. Proper watering practices help plants grow healthy and avoid a host of problems!

4.) Watch for Recovery

After going through all the above steps, watch to make sure that the zinc deficiency starts to clear up within a few days to a week or so. The damaged leaves may not recover completely, but you know you’re in the clear when you stop seeing symptoms on new leaves.

If you cannot get rid of a cannabis zinc deficiency, please consult our 7-Step Cure to 99% of Cannabis Growing Problems

Plant Symptoms

  • Bronze or brown patches
  • Brown or slimy roots
  • Brown or yellow leaf tips/edges
  • Buds dying
  • Buds look odd
  • Bugs are visible
  • Curling or clawing leaves
  • Dark leaves
  • Drooping plant
  • Holes in leaves
  • Mold or powder
  • Pink or purple on leaves
  • Red stems
  • Shiny or smooth leaves
  • Spots or markings
  • Twisted growth
  • Webbing
  • Wilting leaves
  • Yellow between leaf veins
  • Yellow leaves

This page is part of our Plant Doctor series. You can use our tool to filter by symptom and help diagnose your plant.

Problem: A cannabis zinc deficiency causes younger leaves to start yellowing in between the veins. Leaf tips get discolored and may start dying.

Zinc Deficiency – A Nutrient Shortage In Your Cannabis Plant

Published : Sep 14, 2017
Categories : Cannabis cultivation

Nutrient deficiencies can cause an array of issues that growers must recognise before it’s too late. If you’re wondering if your cannabis plant has a zinc deficiency, read below to learn the signs, treatments, and prevention tactics of this deficiency.

Like humans, plants can miss certain nutrients for different reasons. When it comes to cannabis, this becomes crucial as quality control directly influences the quality of the buds yielded. Every grower wants the perfect buds.

Zinc is an essential nutrient in the health of the cannabis plant. It’s crucial for growth, influencing the strength of the branches, stems, and leaves. It is also an indispensable player in the production of chlorophyll, the agent responsible for photosynthesis and the plant’s green colour.

Unlike iron and manganese deficiencies, a lack of zinc affects the immediate growth of your plant. The growth will stagnate until the problem is resolved. If not cared for, this will eventually kill the plant.


As with any nutrient deficiency, the plant will look unhealthy. This is the first sign that you should always look for. The leaves will get soggy and delicate. There are no guidelines for testing a plant when it comes to overall “health,” so it’s up to you to notice. If you have to think hard about whether a plant is healthy or not, it’s because it is. You’ll probably notice the unhealthy leaves just by looking at them.

As mentioned above, the stagnation of growth is a factor to look out for. If your plant seems like it has kept the same height for too long, it is definitely not a good sign. Stopping the growth of the plant is a serious problem. This will not allow new leaves to grow properly, getting them tangled with older leaves. This is why you want to solve the issue as quickly as you can.

Visually, what most deficiencies have in common is a change in colour. You’ll see the change from green to yellow in-between the veins of the leaves. If left untreated, the tips of the leaves will start to turn brown before the entire leaf curls up and dies.


Zinc is available in abundance in most tap water. Therefore, the lack of it is usually not the cause of a deficiency. Similar to other deficiencies, nutrient lockout might be the culprit. This is when the plant is placed under certain conditions that don’t allow the roots to uptake nutrients. It happens even in the presence of nutrients in the growth medium.

Nutrient lockout can be caused by inconsistencies in pH, though sometimes it’s triggered by a stressful environment. In a typical nutrient lockout scenario, the required nutrients are already present, but the roots cannot absorb them.

Cannabis plants rely on a small window of ideal pH levels where they uptake nutrients most efficiently. But this is not the only thing that can cause a lockout. High levels of carbonates, low temperatures, or an excess of phosphorus are also factors that stress the root system enough to stop the uptake of necessary nutrients. Something as simple as engaging in proper watering practices can go a long way when dealing with nutrient shortages.


Make sure you don’t use heavily filtered water or reverse osmosis. These methods contain very little to no zinc. This will mean that eventually, the naturally present zinc in your soil will run out. You’ll be left without any unless you use a supplement.

Make sure you flush your plant with pH-neutral water to remove the nutrient salts that may be preventing the absorption of the zinc you so need. In the soil, ensure the pH is between 6.0-6.5. Make sure you go back to measurements of 6.5-7.0 when you see the problem has subsided. If you have a hydroponic set up, the recommended pH is within 5.5-6.0. Once again, make sure you bump this value up 0.5 after the deficiency goes away.


If the problem was caused by poor nutrition, make sure to supplement your growth medium or nutrient solution with zinc-treated additives.

You can resolve the deficiency by giving a micro-mix compound containing zinc, iron and manganese to your medium. This can surely fix the problem and prevent you from overloading your plant with too much of one specific nutrient. Zinc sulphate, zinc oxide, and chelated zinc are also excellent options to try out.

The tricky thing about adding in nutrients like zinc is that they can react with other nutrients and consequently lock those out. Therefore, if you’re supplementing your system, read the label to understand how it may interact with other nutrients. This is crucial to prevent you from fixing a problem only to bring a new one into the mix.


If everything goes well, after a week or so, you’ll start to see a difference. Old leaves might not fully recover. These may keep their yellowish colour or already brown tips. Watch for the newly born ones. The new leaves will be the best indicator you have. If these appear to be growing healthily, you’ve solved the problem. If the old ones don’t fully recover, you can cut them off as they’ll only be stealing nutrients from the already healthy parts of the plant. Watch if the plant resumes its growing process. If the height increased, you’re in the clear.

We hope this helped you solve a current problem or prevent a future one. Prevention is always better than treatment and keeping yourself informed is half the battle. Be sure to keep up with the latest news in cannabis growth and to follow current literature and research on your favourite plant. There is still a lot to discover about it and there will always be problems to overcome. At least now, you can cross off zinc deficiency from your list of possible problems – you’ll know how to solve this one.

Noticing any weird yellow leaves in your cannabis plant? Zinc deficiency might be the cause! Find out how to solve and prevent this imbalance in nutrients.