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Magnesium deficiency weed

Dealing with magnesium deficiency in weed plants

A magnesium deficiency in a weed plant can quickly turn lethal. Cannabis, like all living things, needs nutrients like nitrogen, potassium, phosphorus, and about 25 others, including magnesium to grow.

Magnesium is important to marijuana plants because it produces chlorophyll, which is crucial for photosynthesis.

Do you think you have a magnesium deficiency in your cannabis plants? Read on to find out what causes it, the signs, the differences between other deficiencies, and how to treat and avoid it. 

What is magnesium deficiency?

What is magnesium deficiency?

Magnesium (mag) is an essential secondary nutrient. Your cannabis crops need it for photosynthesis to convert light into chemical energy. 

When there’s a magnesium deficiency in weed plants, the leaves can’t absorb the light, and photosynthesis can’t happen. 

A magnesium deficiency in a cannabis crop changes the color of the leaves, stunts growth, and could ultimately kill your weed plant.

Magnesium is a mobile nutrient in cannabis plants, so it moves throughout the crop in the stems and leaves. In healthy marijuana plants, the larger leaves send extra magnesium to the newer leaves, and the nutrient circles back. 

A magnesium deficiency in a weed plant can spread quickly in a short time. 

The causes of magnesium deficiency in weed

If you know the causes of a magnesium deficiency in a weed plant, you’ll be able to prevent it. 

Here are some common factors to keep in mind:

  • Coco coir is a popular growing medium. It’s made from the middle fibrous part of the coconut fruit. There are many benefits of using coco coir, but a magnesium deficiency in a weed plant is more likely.

Magnesium, and other cannabis nutrients like iron or calcium, are difficult for the roots to absorb in coco coir. If you’re using this type of growing medium, be mindful of the potential problem. 

  • You can also experience a magnesium deficiency in your weed plants when growing outdoors, as magnesium may be absent in native soil. 
  • Another cause of a magnesium deficiency in cannabis plants is a pH imbalance. If the growing medium has a pH below 5, the roots can’t absorb nutrients properly, which leads to a deficiency. 
  • Overwatering can also lead to a magnesium deficiency in weed plants. When watering weed, ensure the soil is dry. Too much water can flush out nutrients from the growing medium, neutralize the pH, and make the roots soggy. 

These issues render nutrient absorption difficult.

  • Be aware of the type of water you’re using, too. When you use reverse osmosis water, the filter removes trace nutrients and minerals, which can cause a magnesium deficiency in your weed plants. 
  • Flushing your marijuana crop is essential to fix some problems, but you need to replenish the nutrients afterward to avoid cannabis deficiencies
  • Adding more nutrients doesn’t guarantee a perfect growing plant. Overfeeding can lead to magnesium toxicity. It locks out nutrients, causing a magnesium deficiency in cannabis plants. 

What are the symptoms of magnesium deficiency in weed?

Magnesium is critical to chlorophyll production, which keeps plants green. The symptoms of a magnesium deficiency in weed plants show up in the discoloration of leaves and stems. 

Yellow leaves

A healthy marijuana plant has dark green leaves. Magnesium deficiency in weed often manifests as faded green or yellow leaves. The largest leaves at the bottom show these signs first. 

Yellow leaves

Bigger leaves send excess magnesium to smaller, younger leaves. The large leaves continue to do this until they don’t have any magnesium left. As a cannabis magnesium deficiency starts, leaf discoloration sets in. 

Look at the bottom of your crops consistently to check for a magnesium deficiency in your weed plants.

Red stems

A cannabis root system delivers nutrients to the leaves via the healthy, dark green stem. When you’re missing one essential element, the whole function becomes compromised.

When there’s a magnesium deficiency in weed plants, the stems start turning reddish-purple. The discoloration begins at the base of the crop and moves upward. 

Read up on the characteristics of the marijuana strain you’re growing, as some naturally have red stems. In this case, there might not be a magnesium deficiency in your cannabis plants. 

How to tell if you have cal-mag or mag deficiency?

In general, if you’re having an issue with one element, it’s likely all of the nutrients are imbalanced. A magnesium deficiency in weed plants often appears with a calcium deficiency. 

Calcium is immobile in cannabis plants. It helps sugars and nitrogen move through the crop. You can detect a calcium deficiency when the marijuana leaves start to curl, turn yellow, and have brown edges. 

The difference between a calcium and magnesium deficiency in weed plants is that one is mobile and the other is immobile. 

You’ll see yellowing at the bottom of the marijuana plant at first, but a calcium deficiency will stay there, while a lack of magnesium shows up on all parts of the crop. 

Differentiating between magnesium deficiency and other nutrient deficiencies

Are you wondering how to pinpoint a magnesium deficiency in cannabis plants versus other deficiencies? 

Since magnesium is the central element in chlorophyll molecules, quick-yellowing leaves are a red flag for a magnesium deficiency in weed plants. 

Other nutrient deficiencies affect different parts of the plants first. The signs include:

  • Stunted growth
  • Leaves turning reddish or bluish 
  • Drooping leaves 
  • Woody stems 
  • Oddly shaped leaves

How to fix magnesium deficiency in cannabis

How to fix magnesium deficiency in cannabis

Now you know how to spot a magnesium deficiency in weed plants. If you identify any symptoms, you need to act fast. 

Here’s what you can do to rectify the issue: 

Flush your plant and upgrade your nutrients 

When there’s a cannabis magnesium deficiency or another nutrient problem, you’ll need to flush your marijuana plant. 

Follow these steps:

  • Water your weed plant until all of the nutrients wash out.
  • Replenish nutrients with a balanced marijuana fertilizer.
  • Add a magnesium supplement for weed to the fertilizer.
  • Water your marijuana crops with the new mix.

Flush your plant and add supplements

Another way you can fix a magnesium deficiency in your weed plants is to flush them and add supplements.

Follow these steps:

  • Flush the growing medium.
  • Add a preformulated nutrient mix to the growing medium.

You can avoid a magnesium deficiency in weed

You can avoid a magnesium deficiency in weed

Once you fix the magnesium deficiency in your cannabis plants, you’ll want to avoid this problem in the future. These are our recommendations: 

  • A magnesium deficiency in weed plants is most common in the growing medium coco coir. Switching to soil might help you keep your nutrients balanced. 
  • Make sure you have a pH meter in your grow room and check the levels constantly. If the growing medium is too acidic, the roots won’t absorb the nutrients properly, leading to a cannabis magnesium deficiency. 
  • Overwatering can cause problems. Water strips the growing medium of the essential elements. Ensure you’re giving your marijuana plants the right amount
  • Your cannabis feeding schedule should include a balanced fertilizer with an extra magnesium supplement to avoid a magnesium deficiency in your weed plants. 

FAQs related to magnesium deficiency in weed

Here are the answers to some of the most common inquiries about cannabis magnesium deficiency. 

Does weed have magnesium?

Yes, magnesium is an essential secondary nutrient for marijuana plants. It’s vital for the production of chlorophyll, which helps convert light into energy. 

How do you fix magnesium deficiency?

If you think you have a magnesium deficiency in your weed plants, you’ll first need to flush it. After that, you’ll need to replenish the nutrients with a balanced fertilizer. 

One of the best options on the market is the i49 Genetics Nutrients, designed for marijuana crops. 

How do I know if my plants need magnesium?

Yellowing of the bottom leaves is a sign of a magnesium deficiency in cannabis plants. When you notice the discoloration is moving throughout the crop, you’ll know for sure. 

Final points on magnesium deficiencies

If you’re experiencing a magnesium deficiency in your weed plants, the signs are noticeable. You’ll see yellowing starting at the lower leaves and red stems. Flush your plants and upgrade your nutrients or add supplements to fix the issue.

Prevention is always better than cure. Watch the pH balance of your growing medium and water, and remember not to overwater your cannabis plants. Use a balanced fertilizer, too.

Now you know what a magnesium deficiency in weed plants is, so check your crops regularly. Be sure to buy high-quality weed seeds from i49 and start growing today.
We have a massive variety of cannabis seeds, so take your pick. Nurture your plants and remember the signs of magnesium deficiency in weed to prevent and treat the issue in time.