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Iron deficiency cannabis

Dealing with Iron Deficiency in Cannabis Plants

Iron deficiency in cannabis is pretty common, with iron being an essential micronutrient, it’s easy to feed your plants less than they need. With that in mind, don’t feel bad if you experience iron deficiency, but do solve the problem – use the information in this article to help you.

Buying seeds and growing cannabis is all fun and games until you notice yellow leaves and start panicking. Marijuana iron deficiency is an alarming mineral issue for farmers, and letting it fester can ruin your entire harvest.

Iron is a trace nutrient, but its presence can make or break a yield. This mineral helps weed seedlings store energy and grow into rich canopies of greenery.

Are you worried that your new – or even worse, mature – pots are showing signs of cannabis deficiencies? Let’s go through ways to identify and solve an iron undersupply to keep your crops healthy and flourishing.

How does iron benefit your cannabis plants?

Iron plays a vital role in chlorophyll formation, making the leaves bright green and ready to absorb sunshine. Together with carbon dioxide, the light turns into plant food and keeps the weed seed growing.

Apart from this primary function, iron boosts nitrogen uptake, triggering rapid leaf growth.

A lack of iron compromises its ability to collect energy and develop. As a result, the crops get weak, malnourished, and much more susceptible to diseases.

Severe iron deficiency in cannabis can wreck a whole yield, but learning how to recognize the signs can help you stop this issue before it enters full force.

What are the symptoms of iron deficiency cannabis?

Accurate diagnosis is essential when things go wrong in your cannabis garden.

React as soon as your marijuana plants start looking unhealthy, no matter what you assume is the cause. A bit of extra effort now lets you avoid time-consuming, expensive tasks in the long run.

Examine weed leaves

Mineral insufficiency isn’t that straightforward to identify. The symptoms change with the growing stage and resemble other tricky conditions with wildly differing treatment methods.

Early stages

Keep an eye out for warning signs of iron deficiency in early-stage cannabis to nip the problem in the bud.

Differentiating from other mineral deficiencies

Nutrient deficiency manifestations include reduced chlorophyll, stunted growth, and eventual plant death. Jumping to conclusions and treating an issue that isn’t there can lead to this worst-case scenario.

Each mineral deficiency comes with sets of red flags that help you differentiate between various issues and pick the best treatment option. For example:

It’s especially tough to tell whether you’re facing a shortage of magnesium or iron, which brings us to our next point.

Chlorosis in young leaves

Chlorosis is the scientific term that describes leaf yellowing due to a lack of chlorophyll. It can appear as a consequence of various ailments, but when it comes to iron scarcity, the condition hits the newest growth first.

If you’re seeing such discoloration at the middle or base of the bush, look for other potential causes. Young leaves in various shades of yellow point to an iron-based issue.

Later stages

The later you pick up on this issue, the less likely you’ll get a rich harvest. It’s better late than never and you still have the chance to save your mature marijuana. Watch for the following signs.

Leaf chlorosis starts to affect all leaves

As the issue progresses, the yellowing spreads from the leaf center to its entire surface. It eventually reaches the branches and the rest of the crop.

These leaves can’t collect chlorophyll for photosynthesis, which causes the plant to develop much slower and eventually stop growing altogether.

Leaves start to drop off

Cannabis can keep living on a shortage of nutrients for some time, but the leaves will eventually start falling off. While you might see some buds, they’re much fewer and smaller than you’d get from a same-sized healthy plant.

What causes cannabis iron deficiency?

Getting to the root of the problem lets you treat your cannabis plant iron deficiency now and avoid the same thing from happening in the future. The following are common culprits worth looking into.

Poor drainage

There are trace amounts of iron in any soil type, but some conditions make it hard to absorb.

Crops in poorly drained soil don’t get enough oxygen, causing them to take up fewer grow-promoting minerals. Coco coir could also be problematic, requiring substantial treatment to provide a healthy, nutrient-dense environment for your seedlings.

You’ll need to get a bit more creative with outdoor gardens and natural environments. For instance:

  • Try to choose a spot of light earth for your planting efforts.
  • Avoid clay as much as you can – it has notoriously poor drainage.
  • Import a mix in dull gray gardens and amend the soil before even buying seeds, let alone putting them into the ground.

Excess of other minerals

Even if your soil or hydroponic medium is rich in iron, overdoing it with the minerals won’t do your plant any good.

Beginner growers are often so worried about insufficiencies that they go overboard with zinc, copper, calcium, and anything else they can think of. The nutrient buildup blocks the plant’s iron uptake, making your feeding efforts counter-productive.

It’s good to feed your herbs generously but choose balanced fertilizers, cannabis nute mixes, and plant foods to avoid taking it to the extreme.

pH imbalance

Neutral and alkaline pH levels could also be causing iron issues in your garden. An imbalance can be a consequence of poor soil in general or overfertilization by eager growers.

pH measuring

If you reckon that acidity is the reason behind the situation, get yourself a pH meter and check the levels regularly, not only when you notice signs of distress.

Once you verify your suspicions, flush the soil with clean, pH’d water to remove nutrient salts.

  • In soil, 6.0 – 6.5 pH is ideal.
  • In coco and hydro, strive for a 5.5 – 6.5 range.

Maintaining these levels is a win on all fronts, as it also helps your crops absorb other nutrients.


Soaking your pots with too much water can cause drainage holdups, no matter how high-quality a medium you’re using.

Watering cannabis

An overabundance of moisture builds pools in the soil, preventing the roots from absorbing all the nutrients they require for healthy growth. So, make proper watering practices your best friend and dedicate yourself to providing enough H2Oin regular, slow strokes.

How do you treat iron deficiency in cannabis plants?

Once you confirm that you’re dealing with an iron issue and determine the underlying reasons, it’s time to act. A quick response is necessary to return your plants to their healthy, blossoming selves.

While they’re far from cure-alls, these two approaches can do wonders, especially if you take action early.

Prune affected leaves

Experts often describe iron deficiencies as immobile, which is good news for you. Since the condition doesn’t spread quickly down to the roots, the entire crop doesn’t have to suffer.

Pruning the tips is a viable option during the vegetative growth stages.

You could ‘prune and pray,’ but it’s much better to tackle the underlying causes after cutting off the affected blades. Examine and correct the pH levels and nutrient doses to see new, green, brilliant leaves replace the old yellow ones.

Pruning helps you control plant height and encourage multiple tops to replace the impaired foliage. Once you get rid of the leaves that only weighed down the crop, keep it healthy and strong by employing preventative practices and providing the optimal growth environment.

Flush and amend nutrients

A cleansing flush is another treatment program to bring your herbs back to life.

Poor soil, drainage holdups, and too much fertilizer provoke nutrient lockout. Flushing should remove the amassed nutrient salts. Follow these steps:

  1. Flush the grow medium with 6.0 pH water to cleanse any excess minerals.
  2. Soak the pots with a cannabis-specific nute solution.
  3. Regularly check pH levels to prevent a similar problem from developing again.

Make a switch to nutrients that cater to the specific needs of the strain you’re cultivating. It’s not a small investment, but dealing with sickly plants and frequent soil changes is even less wallet-friendly.

Cannabis iron deficiency is rare but solvable 

The deficiency should start to clear up within a week of applying these solutions. While not every leaf will recover completely, young green foliage means you’re off the danger list.

Either way, remember that the only way to turn things around is by acting fast. Iron deficiencies occur gradually, but they can spread and wreak havoc on your plant’s health, ruining an otherwise perfect harvest.

Now that you’re aware of and know how to fix iron deficiencies in cannabis, you’ll be ready to tackle the problem head-on the next time it happens. Don’t forget to check out our online store to get the best quality weed seeds just in time for your next harvest season.

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