How to Recognize and Fix Cannabis Deficiencies

  • April 15, 2022
  •  Comments : 0
  • Last modified on April 22nd, 2022 at 10:12 am
Cannabis Deficiencies

Just like humans, nutrients are essential to the survival of the cannabis plant. Different types of nutrients are important to plant growth, including micronutrients and macronutrients. These nutrients may include zinc, boron, nitrogen, magnesium, calcium, and copper. There are recognizable signs that follow the deficiency of these nutrients.

How to Recognize and Fix Cannabis Deficiency

The cannabis plant needs macronutrients like potassium, phosphorous, and nitrogen for optimal growth. Micronutrients like calcium, copper, chlorine, and zinc are also required if it is only in tiny amounts. Cannabis that lacks any of these nutrients will show some signs. Some of the common cannabis deficiencies may include:

#1 Boron deficiency

Boron deficiency

Boron plays an essential role in the growth of the cannabis plant cell. A cannabis deficiency of this nutrient can be seen at the tip of both the shoots and roots. The general symptoms of this deficiency may include distortion and stunting of the growing tip. This may lead to brittle foliage, death, or the lower leaf becoming yellow.

The major signs of boron deficiency may include:

  • Chlorosis
  • Hollow stem
  • Rough stems
  • Thick leaf tips
  • Abnormal leaf tips

How to fix boron deficiency

Starting your seed in high-quality soil containing boron is the best way to correct this deficiency. However, there are methods you can try if you start seeing symptoms of boron deficiency in the plant. These may include:

  • Ensuring the plant has adequate moisture
  • Using a humidifier inside your grow room
  • Adjusting the pH of the soil
  • Stop the use of heavily filtered water or reverse osmosis

2. Calcium deficiency

Calcium deficiency

Calcium is an important component of cell membranes and cell walls. Root tips and new leaves will show curling, discoloration, and unusual growth if your cannabis plant suffers from this deficiency.

The major signs of calcium deficiency may include:

  • Dark veins
  • Brown or yellow spots
  • Yellowing at the edges of the leaf
  • Death of root tips
  • Dying leaf tips
  • Malformed leaf tips
  • Parachute-shape leaves

How to fix a calcium deficiency

The remedy for calcium deficiency is not adding more calcium to the plant, unlike some nutrient issues. Fixing this deficiency can be achieved by:

  • Prevent stagnant water in the growth environment by adding fans to it
  • Increase the pH level of the soil to about 6.0 and 6.5
  • Increase the grow room’s temperature
  • Increase the amount of water the plant gets

3. Copper deficiency

It is common for leaves directly beneath light to show signs of copper deficiency. It is in the flowering stage where the leaves of the cannabis plant develop a reddish or dark purple hue. At this stage, some strains develop copper deficiency.

The signs of copper deficiency in the cannabis plant may include:

  • Buds grow slowly or do not ripen
  • Leaves may feel stiff and even begin turning under
  • Leaves may develop a metallic or shiny sheen
  • Edges and tips of leaves turn white or bright yellow
  • Leaves turn black with purple or blue undertones

How to fix the copper deficiency

Just like most cannabis deficiencies discussed, adding more nutrients to the soil is not the first step to take to fix the issue. This deficiency can be fixed by:

  • Not over-watering the plant
  • Keeping plant hydrated using tap water
  • Adjust the pH level of the soil to the correct range

4. Magnesium deficiency

The symptoms of magnesium deficiency will begin in the lower leaves. This will then find its way to the upper part of the plant through the middle part. The plant’s growing shoots will change from pale green to white. The stems and petioles will also turn purple.

The common signs of magnesium deficiency to look for in your cannabis plant are:

  • Plant sags or withers
  • Leaves droop or wither
  • Leaves curl up or under
  • Leaves or plants develop twisted growth
  • Leaves develop patchy, speckled, or spotty patterns
  • Old leaves drop off
  • Veins stay green

How to fix a magnesium deficiency

You will need to add more nutrients to the soil to fix the magnesium deficiency in your plant.

Getting the following from your local garden store will help.

  • Epsom salts
  • Magnesium sulfate
  • Dolomite lime
  • Worm castings
  • Garden line

You should follow the instruction on the package to get started. It is recommended that you try Epsom salts as it is water-soluble, easy to find and work with, and relatively cheap.

5. Nitrogen deficiency

Slight discoloration in mature leaves of the cannabis plant is an early sign of nitrogen deficiency. The plant appears thin and pale as it grows. This is because of insufficient branching that will eventually make the plant fade and die.

The signs of nitrogen deficiency to look for in your cannabis plant are:

  • Premature fading and death of the plant
  • Considerable decrease in yield volumes
  • Tissue develops necrosis
  • Curling and shedding of leaves
  • Chlorosis spread from the lower to the top parts of the plant
  • Petioles and veins become reddish
  • Smaller leaves and leaf stems turn purplish or reddish
  • Larger pale-green leaves turn to white and yellow

How to fix nitrogen deficiency

Inadequate presence of nitrogen is common as deficiency of cannabis goes. However, it is easy putting nitrogen back to where it should be in the soil. Its presence in the soil of your weed will ensure that the plant grows strong. Some good sources of organic matter with the required level of nitrogen include:

  • Coco peat
  • Groundnut husks
  • Nettle slag
  • Blood meal
  • Fish meal
  • Bone meal
  • Horn meal
  • Nitrogen-fixing plants like legumes
  • Animal manure
  • Compost

You must be mindful of adding manure to the soil; this is because the concentration of nitrogen differs for different animals. As a result, do research before using the option you think is best for your cannabis plant.


Plants are similar to humans in terms of needed nutrients for their survival. This is the same with the cannabis plant. There are cannabis deficiencies that become obvious when the plant lack some nutrients. In case you notice any of the symptoms, ensure that you fix them as soon as possible otherwise you can also contact any reputable company like BC Seeds to get proper information about it. This is to make sure that your cannabis plant grows optimally.

Mr. BC Seeds
Mr. BC Seeds is an over educated old school hippy who has been involved in the cannabis industry since the 1970's. He is one of the most experienced marijuana breeders in Canada if not the entire world. He was the first to use the most advanced breeding techniques in 2008 to create 42 of the world's strongest cannabis strains. He has been writing in-depth articles about cannabis in Canada for decades and looks forward to continue bringing you cutting edge cannabis strains for the decades to come. Mr. BC Seeds uses a "pen name" because he still travels the world collecting cannabis strains and continues researching cannabis in laboratories of non-legalized countries.
Posted in Cannabis and tagged Cannabis deficiencies

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