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Manganese Deficiency In Marijuana Plants

Manganese Deficiency In Marijuana Plants

Manganese is vital for disintegrating enzymes, creating chlorophyll and as part of the photosynthesis process. It also makes sure nitrates can be used for creating proteins, very important for marijuana plants.

Manganese defects are quite infrequent and usually has something to do with a lack of zinc and iron. Read this article and learn how to recognize and fix a manganese deficiency in your marijuana plants.

Signs of a manganese deficiency

Sings of manganese deficiency weed

When new leaves begin turning yellow and show small, brown colored malignant spots in the center of the leaf, this is a sign of manganese deficiency.

Usually, the veins on the leaf stay green. The outside part of the leaf turns a dark green color. If the plant has too much manganese, it will cause a lack of iron. Manganese is fixed and doesn’t travel throughout the plant.

Download my free marijuana grow guide at this link for more growing tips

The leaves could turn yellow between the veins, having speckles of brown spots on the damaged leaves. It is possible for the lifeless brown spots to expand and destroy the entire leaf. Another thing - the leaves could fragment and disintegrate.

Manganese deficiency will stop the growth of your plant. It starts to become yellow at the bottom of the leaf, then spread more noticeably, getting closer to the tips. Not sure if your plants have a manganese deficiency? Read the article Nutrient deficiencies in marijuana plants for a list with pictures of all deficiencies.

How to fix a manganese deficiency

Fix manganese deficiency weed

If your plant lacks manganese and you are in desperate need of help, try foliar feeding your plant with a fertilizer that is highly soluble in water and has plenty of manganese in it. The fertilizer you choose can be a hydro micro, a unique Fe-Zn-Mn fertilizer, or also a manganese chelate.

You can simply add the fertilizer to your water nutrient solution. You can try compost and greensand, as they are high in manganese, but their consumption rate is less. Marijuana Booster is a great product to use if you want to make sure you have a good mixture of all nutrients.

List of marijuana plant symptoms

Leaf Color: 
- Pale Color Leaves
- New Leaves Turning Yellow
- Lower and Older Leaves Yellowing
- Yellowing Between Veins
- Veins of Leaves Stay Green
- Brown or Dark Spots
- Speckling / Patchy Pattern

Leaf Symptoms: 
- Top Leaves / Newer Growth Damaged
- Lower Leaves / Older Growth Damaged
- Yellowing Between Veins
- Veins of Leaves Stay Green
- Spots
- Speckled / Patchy
- Less Growth
- Unusual Growth

Plant Symptoms: 
Slow Growth

Prevent deficiencies

Prevent manganese deficiency cannabis

If the pH is too high, or your plant has an overabundance of iron, it may start showing evidence that it is lacking manganese.

Now keep in mind, once you get rid of manganese deficiency, it could take up to one week before the issue is no longer spreading. Any leaves that were harmed because of the deficiency mostly likely will never bounce back, so instead look at the other parts of the plant to determine that it is getting better.

When growing marijuana in soil the roots will consume manganese far better in the pH ratio of 6.0 - 7.0. Although there are growers who prefer having the pH set more in the 6.0 – 6.5 range when you think you have a manganese deficiency.

If you are hydro growing, the roots will consume manganese much better somewhere in the 5.5 – 5.8 pH ratios. Usually when hydro growing it is better to have the pH set around 5.5 – 6.5, but manganese does consume better at 5.8.

Download my free marijuana grow guide at this link for more growing tips

If you ever think your marijuana plant is lacking manganese, go ahead and fill your system with pure, pH water that has a normal amount of the necessary nutrients for marijuana (which should contain manganese). Doing this gets rid of additional iron and salts that could be blocking the absorption of manganese. It also brings the pH levels where they need to be while giving your plant nutrients it was lacking.

You want to stay away from high pH ranges which easily cause your plant to lack the proper amount of manganese. If for any reason you can’t resolve your deficiency issue, check out our support page for more help.

Thanks for reading. Please leave comments or questions below and don't forget to download my free grow bible


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Comment Section

15 thoughts on “Manganese Deficiency In Marijuana Plants

By Jesse on 31 October 2014

I've been having a hell of a time with my nutes since I started my 2 months ago. I'm hoping someone on here might have some helpful info. I'm using coco with a flood and drain table. I went heavy with the nutes and locked them up but I did a good flush and stayed over with a new mixture but ever since then they just won't grow. Like I said, 2 months and the tallest one is 6". They are very pale green/yellowish and are now all of them are staying to get dead tips on the end of the leaves. I've done extensive research and can't pinpoint the issue. Does anyone have any suggestions for me?

By Aaron on 29 October 2017

To hit back off the united

By Sweet Baby Ray on 25 February 2015

Can I use your booster nutrients in conjunction with Canna hydroponic nutrients?

By Faceless on 15 June 2015

Have you checked your oh? Ph is always first priority even before nutrients. Having the proper ph when you flush is essential to helping the recover from lockout.

By Richard on 15 June 2015

Question... I have a plant that was vegging for first two months, than for a month I budded , now it's vegging again.. Should I get rid of it or let it keep growing. Thank you

By joe boi on 27 January 2016

New to ge
Rowning this type of croup any advice on starting had good results withblac magic worm casing worm po lol gonna try nails for iron? A good top soil? Whats a good soilmix to start with? Findmyself peoblestart with?

By Mamma Luca on 6 April 2017

Say what? what language do you speak fluently...use spell check friend... to grow is to communicate your needs clearly, then the wealth of information ... cause you have questions will flow, like the weed you want to grow.... Cheers.

By latewood.ILGM on 3 February 2016

joe b oio,

I had a hard time understanding exactly what you are asking. I believe that you would be best served by joining our Support Forum, where we have many experts and knowledgeable members will to guide you. Peace, lw

By Tumblecreekkid on 23 June 2017

Have Amnesia Haze Autoflower, started over sixty days ago .Now shows signs of flowering .I am getting Tiger Bloom by Fox Farms .Is this the best product for this time in my grow cycle ?

By latewood.ILGM on 11 July 2017


I am sorry mu friend. I cannot say that that is you r best option as tiger bloom is only 1 of 2-3 parts of the Fosfarm Trio system, used in the flowering stage. Join our friendly forum and learn what you need to be successful.

We have a mature knowledgeable membership. We are a happy forum. 🙂

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