Mg Deficiency When Using Coco

[Dastardly]

First Off i am not sure if this needs to be here or in the "Sick Plants" section

But my Question is, Is it possible/likely for plants grown in Coco to have a MG Deficiency ?

As i have just been looking through the pinned topic "Espom Salts, (Mg) deficient" and the pictures are resembling some of my leaves. But after a search on the subject i couldn't find anyone that has that problem growing in Coco.

Currently Using the Canna range Coco, A & B.

Cheers

[Owderb]

Its possible to get a mg def no matter which way you grow, its just that it happens more often when growing in compost but yes it can happen

Owd

[Grimweeder]

i seem to get it in coco more than in soil, still dont get it much tho.

[Cheech]

I always find coir to be mg hungry in comparison to previous compost and hydo grows.

I think the reason for this is that coir is naturally quite high in potassium which, if it builds up, can cause some competition with ca and mg. Coir is also known for drawing down ca which can cause some mg related issues.

Just make sure you water plenty to get enough run off and use a bit of epsom when needed.

[Dastardly]

Looks like i may have to give them a dose.

Anyone reccomend how much to give them, as its not effecting the whole plant, just some of the big shader leaves, so was thinking a low dose ?

[Coco-san]

Looks like i may have to give them a dose.

Anyone reccomend how much to give them, as its not effecting the whole plant, just some of the big shader leaves, so was thinking a low dose ?

Mg is one of the mobile nutrients, so what happens is the Mg actually displaces itself within the plant from older leaves to newer ones when there is a deficiency.

Epsom Salts contain 10% MgSo4

1 gram / 3.78 liter water = 26.5 ppm

2 gram / 3.78 liter water = 53 ppm

feed at pH over 5.8

However, you want to mindful of the fact that feeding continuously over pH 5.8 can lead to a Ca / Mg imbalance in coco.

Edited February 4, 2010 by Coco-san

[GreenNinja]

Dastardly -

What pH are you feeding your plants at? Long shot I know, but as Coco-san has alluded to, the pH will affect which nutrients are absorbed (i.e. different ones at different pH). I've only ever seen Mg deficiency in my recent organic coco test, everything else on coco-specific feeds has been fine...and I've grown a lot of different strains. Not saying it can't/doesn't happen, but the coco feeds are developed specifically to handle the different Mg requirements. I've now grown with Canna, B'Cuzz and Plant Magic base nutes and all 3 have been fine for all deficiencies, so unless you've got a particularly fussy strain or pheno, or maybe very soft water, my best guess is pH.

GN