Common Cannabis Deficiencies & Cannabis Deficiency Chart

Are you struggling to figure out what’s wrong with your Cannabis plants when leaves start looking sick? A Cannabis deficiency chart is your best friend for quickly identifying exactly what nutrients your plants are missing.

I know how confusing it feels when yellowing leaves, brown spots, or twisted growth suddenly appear on healthy plants. Different deficiencies create unique visual patterns that tell you precisely what’s going wrong with your crop.

Using a Cannabis deficiency chart helps you match symptoms to specific problems so you can fix issues fast. I’m going to show you how to read these signs and get your plants back on track.

Let’s swoop into everything you need for healthy, blossoming Cannabis.

The Basics of Cannabis Deficiencies

Cannabis deficiency happens when your marijuana plants don’t get enough essential nutrients they need to grow healthy and strong.

Just like people need vitamins and minerals, Cannabis plants require specific nutrients to flourish and produce quality buds.

When plants lack these nutrients, they show visible signs like yellowing leaves, stunted growth, or brown spots on foliage.

The most common deficiencies involve nitrogen, phosphorus, potassium, calcium, and magnesium that plants absorb through their roots. Each deficiency creates different symptoms that help you identify exactly what your plant is missing.

A Cannabis deficiency chart can really help you match symptoms to specific nutrient problems quickly and accurately.

Understanding these signs early helps you fix problems before they seriously damage your crop and overall yield.

Printable Cannabis Deficiency Chart

A printable Cannabis deficiency chart is a handy reference tool you can keep right in your grow room. Print it out and hang it on the wall so you can quickly match leaf symptoms to specific nutrient problems.

Having a visual guide nearby saves time when diagnosing issues and helps you take fast action before problems get worse.

DOWNLOAD CANNABIS DEFICIENCY CHART

Cannabis Deficiencies Explained In-Depth 

I’ve learned that each nutrient deficiency creates unique symptoms that help identify exactly what your plant is missing.

Understanding these differences has made diagnosing and fixing problems much faster and more effective for me.

1. Nitrogen Deficiency in Cannabis

Nitrogen deficiency is one of the most common problems you’ll see in Cannabis plants during their growth cycle. The older, lower leaves start turning pale yellow or lime green first, then the yellowing slowly moves upward.

Eventually, these affected leaves become completely yellow and fall off the plant if you don’t address the problem. Nitrogen is crucial for healthy leaf growth and overall plant development throughout the vegetative stage.

• Common Causes: Plants use up nitrogen quickly during vegetative growth, or the soil lacks enough nitrogen.
• Fixes: Add nitrogen-rich vegetative fertilizer, or use organic options like fish emulsion or compost tea.

2. Phosphorus Deficiency in Cannabis

Phosphorus deficiency makes your Cannabis leaves turn dark green, blue, or purple, especially on the undersides and stems. Growth becomes noticeably slower, and leaves might develop dark brown or bronze spots that look almost burnt.

This deficiency often appears during the flowering stage when plants need lots of phosphorus for bud development. Cold temperatures and incorrect pH levels can prevent your plants from absorbing phosphorus even when it’s available.

• Common Causes: Cold temperatures below 60 degrees or pH levels outside the ideal range prevent phosphorus absorption.
• Fixes: Adjust pH to the correct range and increase temperatures, then add phosphorus-rich bloom fertilizer.

3. Potassium Deficiency in Cannabis

I’ve noticed that potassium deficiency shows up as burnt-looking brown edges on leaves that curl upward at the tips. You might also see yellow or brown spots scattered across the leaf surface randomly.

This problem seriously affects flowering because potassium is essential for bud development and overall plant health. Without enough potassium, your buds won’t develop properly, and yields will be disappointing at harvest time.

• Common Causes: Overwatering or nutrient lockout from incorrect pH, or the fertilizer lacks enough potassium overall.
• Fixes: Check and adjust pH levels first, then feed with bloom nutrients high in potassium.

4. Calcium Deficiency in Cannabis

Calcium deficiency causes new growth to look twisted, distorted, or crinkled at the top of your plant. Brown spots appear on newer leaves, and the edges might curl or die back completely.

This problem is especially common in hydroponic systems and coco coir grows where calcium isn’t naturally present. Root development also suffers badly because calcium is essential for strong cell walls and healthy root growth.

• Common Causes: Using reverse osmosis water or coco coir without calcium supplements, or pH imbalances.
• Fixes: Add cal-mag supplements to the feeding schedule regularly, or switch to calcium-containing water.

5. Magnesium Deficiency in Cannabis

Magnesium deficiency creates a distinctive pattern where the areas between leaf veins turn yellow while the veins stay green. This usually starts on older, lower leaves first and then spreads upward to newer growth over time.

It looks different from nitrogen deficiency because the leaf veins remain bright green instead of yellowing completely. Magnesium is essential for chlorophyll production, which plants need to convert light into energy for growth.

• Common Causes: Low pH levels, overuse of calcium or potassium blocking magnesium, or a growing medium that lacks magnesium.
• Fixes: Apply Epsom salt as a foliar spray or add it to your regular feeding solution.

6. Iron Deficiency in Cannabis

Iron deficiency makes new growth at the top of your plant turn pale yellow or almost white. The youngest leaves show symptoms first, while older leaves stay completely green and healthy-looking.

Leaf veins might stay slightly green while the rest of the leaf turns pale. This deficiency rarely happens because of a lack of iron, but usually because pH problems prevent absorption.

• Common Causes: High pH levels above 7.0 lock out iron and prevent root absorption.
• Fixes: Lower pH to the proper range immediately, and consider adding chelated iron supplements.

7. Zinc Deficiency in Cannabis

Zinc deficiency causes new leaves to grow twisted, small, and deformed with unusual shapes that don’t look normal. The spaces between leaf nodes become shorter, making the whole plant look stunted and compressed together.

Leaf tips and edges might turn brown or burnt-looking, and overall growth slows down dramatically. I’ve watched plants struggle to develop properly when zinc levels drop too low in the growing medium.

• Common Causes: High pH levels prevent zinc absorption, or water contains too much phosphorus, blocking zinc.
• Fixes: Adjust pH to the optimal range and add zinc supplements carefully without overdoing it.

8. Manganese Deficiency in Cannabis

Manganese deficiency creates a speckled or spotted yellowing pattern on leaves that looks like tiny yellow dots everywhere. New growth shows symptoms first, unlike iron deficiency, which affects the entire leaf more uniformly.

The yellowing appears more random and scattered compared to the interveinal pattern of magnesium deficiency.

Manganese helps with photosynthesis and nitrogen use, soa deficiency really slows down overall plant growth significantly.

• Common Causes: High pH above 6.5 in soil or 6.0 in hydro, or excessive iron blocks uptake.
• Fixes: Lower pH to appropriate levels, then add manganese sulfate or a complete micronutrient supplement.

9. Sulfur Deficiency in Cannabis

Sulfur deficiency causes new leaves to turn pale yellow or lime green, starting from the top. It looks similar to nitrogen deficiency, but sulfur problems affect newer growth first instead of older leaves.

Stems might also turn purple or red, and the whole plant appears pale and weak. Sulfur is needed for protein production and helps plants develop strong cell structure throughout their lifecycle.

• Common Causes: Rare but happens with reverse osmosis water or hydroponic nutrients lacking sulfur completely.
• Fixes: Add Epsom salt containing sulfur and magnesium, or use sulfur-containing Cannabis supplements.

10. Copper Deficiency in Cannabis

Copper deficiency makes new leaves turn dark green or bluish with tips that curl and twist downward. Young leaves might look shiny or metallic, and growth becomes very slow and weak overall.

Stems become thin and are unable to support the plant’s weight properly as it tries to grow. This deficiency is pretty rare in Cannabis growing, but it can happen with certain soil types.

• Common Causes: Very high pH or excessive phosphorus and zinc block copper from being absorbed.
• Fixes: Adjust pH to the optimal range and use a complete micronutrient blend with safe copper amounts.

11. Boron Deficiency in Cannabis

Boron deficiency causes new growth to become thick, brittle, and easy to break off accidentally when touched. Growing tips might die completely, and stems can develop hollow areas inside that weaken the structure.

Root development suffers badly, making it hard for plants to absorb water and nutrients efficiently. Leaves at the top might look burned or develop brown spots that spread quickly.

• Common Causes: Low-humidity environments, inconsistent watering, or pH imbalances prevent boron from moving through plant tissue.
• Fixes: Apply boron supplements very carefully in tiny amounts since too much causes serious permanent toxicity.

12. Molybdenum Deficiency in Cannabis

Molybdenum deficiency makes middle and older leaves turn yellow or orange while leaf edges curl upward. The symptoms look similar to nitrogen deficiency because molybdenum helps plants use nitrogen properly for growth.

Without enough molybdenum, plants can’t process nitrogen even when plenty is available in the soil. This deficiency is extremely rare in Cannabis growing and mostly happens in acidic soil conditions.

• Common Causes: Very low pH below 5.5 prevents uptake, or the growing medium naturally lacks this trace mineral.
• Fixes: Raise pH to proper levels, and add a complete micronutrient supplement containing molybdenum safely.

13. Chlorine Deficiency in Cannabis

Chlorine deficiency causes leaves to wilt even when the soil is moist, and they might develop a bronze color. Younger leaves show symptoms first and can become pale or yellow over time if not corrected.

This deficiency is incredibly rare because chlorine is present in most tap water naturally. Plants only need tiny amounts of chlorine, so deficiency almost never happens in normal growing conditions.

• Common Causes: Using only distilled or reverse osmosis water with no minerals, or sterile hydroponic systems.
• Fixes: Switch to regular tap water occasionally, or add chlorine through complete hydroponic nutrient solutions.

14. Nickel Deficiency in Cannabis

Nickel deficiency affects seedlings more than mature plants, causing slow growth and pale, weak-looking leaves from the start. Plants can’t process nitrogen properly without nickel, which leads to symptoms that look like nitrogen deficiency.

This is one of the rarest deficiencies you’ll ever see in Cannabis growing operations. Most growers never encounter this problem because plants need extremely small amounts of nickel to function.

• Common Causes: Heavily filtered water systems or completely sterile mediums that contain absolutely no trace minerals.
• Fixes: Use tap water sometimes or add complete micronutrient supplement that includes all trace elements.

Cannabis Deficiencies vs Nutrient Burn

Knowing whether your plant lacks nutrients or has too many is crucial for proper treatment. Here’s how I tell the difference between these two common problems:

I’ve learned to always check pH levels first before treating any plant problem. Getting the diagnosis right from the start has saved me from causing unnecessary stress and damage to my plants.

pH Problems that Mimic Cannabis Deficiencies

pH problems often look exactly like nutrient deficiencies but require completely different solutions. Wrong pH levels prevent roots from absorbing nutrients even when they’re present in the soil.

Nutrient lockout happens when pH is too high or too low for proper absorption. Soil growers need a pH between 6.0 and 7.0 for optimal nutrient uptake. Hydroponic systems work best with a pH between 5.5 and 6.5 for healthy growth.

Each nutrient absorbs best at specific pH levels, so maintaining a proper range is crucial. If pH drifts outside ideal ranges, your plants can’t access nutrients regardless of the feeding schedule.

Always test and adjust the pH before assuming your plant has a true nutrient deficiency. Fixing pH often solves what looks like multiple deficiencies at once.

Cannabis Deficiencies Based on the Growth Stage

I’ve noticed that Cannabis plants need different nutrients at each stage of their lifecycle. Understanding what deficiencies happen during each growth phase has helped me catch problems early:

Matching your feeding schedule to each growth stage prevents most deficiency problems from happening. Paying attention to what your plants need at different times leads to healthier growth and better harvests.

Preventing Cannabis Nutrient Deficiencies

Preventing deficiencies is much easier than fixing them once they appear. Here are the key steps to keep your plants healthy:

• Proper feeding schedules: Follow a consistent nutrient schedule designed for Cannabis, adjusting amounts based on your plant’s growth stage and specific needs.
• Water quality: Test your water’s pH and mineral content regularly, and use filtered or treated water if tap water is too hard or alkaline.
• Routine plant checks: Inspect leaves daily for early warning signs like discoloration, spots, or unusual growth patterns that indicate developing problems.
• Keep growing records: Track what you feed, when you feed, and any problems that occur to learn patterns and improve future growth.

I’ve learned that daily plant checks save me from major problems later. Catching issues early has dramatically improved my growing success and harvest quality.

That’s a Wrap

A Cannabis deficiency chart is truly your most valuable tool for keeping plants healthy and productive throughout their entire lifecycle.

I hope what I’ve shared helps you spot problems early and fix them before serious damage to your crop occurs. Remember that proper pH levels and balanced feeding prevent most deficiencies before they affect growth.

Keep your chart nearby so you can quickly match symptoms to solutions whenever leaves look strange or unhealthy.

Early action makes the biggest difference between minor setbacks and major crop losses that hurt your final harvest.

Trust what you see and adjust your approach when plants need help. What deficiencies have you encountered? Share your story in the comments below.