Where to find Magnesium

[JimmerG]

I'm suffering slightly from the odd yellow leaf - notably my curcurbits - although they've just gone in the ground so I'm hoping they'll green up having been stuck in pots for a month.

But my summer rasps are also a little yellow of leaf - mostly last year's growth, the new growth is lovely and green.

So, is this normal? Does is sound like a magnesium deficiency? If it is, is there an easy way of supplying it. Maybe I need nitrogen would that sort out yellowness?

I'm brewing comfrey and nettle fertiliser - would either of these contain magnesium - or will I have to resort to a trip to the GC?

PS - Had an EXCELLENT day on the allotment yesterday - FINALLY managed to plant EVERYTHING apart from my rather weedy looking brassicas!

J

[zazen999]

Epsom salts, and you don't have to do anything other than sprinkle it around the roots and water it in, or let mother nature water it in for you.

[SarzWix]

Epsom Salts - either from the GC or the chemists. Between a teaspoon and a dessertspoon (depending on size of plants) sprinkled round the base of the plants and watered in, or mixed with water and sprayed on the leaves.

[Florence Fennel]

Thank you. Been to buy some Epsom salts today, but the book advice I have had was to dilute it 30g to 0.5 litres of water and water it in. I haven't done it yet, so will go for the sprinkling.

[Snadger]

You could use magnesium limestone sprinkled around the plants. It is a brown colour similar to dolomite!

[chloe666]

seaweed

I'm suffering slightly from the odd yellow leaf - notably my curcurbits - although they've just gone in the ground so I'm hoping they'll green up having been stuck in pots for a month.

But my summer rasps are also a little yellow of leaf - mostly last year's growth, the new growth is lovely and green.

So, is this normal? Does is sound like a magnesium deficiency? If it is, is there an easy way of supplying it. Maybe I need nitrogen would that sort out yellowness?

I'm brewing comfrey and nettle fertiliser - would either of these contain magnesium - or will I have to resort to a trip to the GC?

PS - Had an EXCELLENT day on the allotment yesterday - FINALLY managed to plant EVERYTHING apart from my rather weedy looking brassicas!

J

try seaweed extract...supposed to be very good..I used some on my beans and corgettes on sunday...will let u know the results soon

[Edwardo82]

I have used seaweed extract on a lot of my plants this year and it really works wonders.

I would definitely try it out as well JimmerG

[solway cropper]

Snadger's right about the magnesium limestone but it's only found in a very small part of the country and is fairly insoluble so would be very slow release. If you want quick results the epsom salts is best

[King Carrot]

You could use magnesium limestone sprinkled around the plants. It is a brown colour similar to dolomite!

Dolomite Lime contains some magnesium - not sure about being a quick fix though as I use it in a general fertilizer and understand it has more of a slow and steady release

[FionaH]

My clematis has been going yellow from the bottom leaves and working up, will try epsom salts

[Two_Sheds]

this won't win me any friends:

"The science behind the use of Epsom salts is only applicable to intensive crop production in
situations where magnesium is known to be deficient in the soil or in the plants. It is
irresponsible to advise gardeners and other plant enthusiasts to apply Epsom salts, or any
chemical, without regard to soil conditions, plant needs, and environmental health"
so says a Prof. of Horticulture http://www.puyallup.wsu.edu/~Linda%2...om%20salts.pdf

[teakdesk]

From the same article...

"Excessive levels of potassium contribute to a mineral imbalance that causes magnesium deficiency in a variety of species, even when soil levels of magnesium are adequate. High levels of soil potassium apparently interfere with root uptake of magnesium. Addition of nitrogen and/or reduction of available potassium are both recommended to overcome this indirect magnesium deficiency"

This is basically saying that many gardeners have soils and compost that have enough magnesium and don't need Epsom Salts adding but if we add to much potash (potassium) in our fertiliser we will stop the plant absorbing the magnesium that is there.

If we feed with too much tomato feed (or any other high potash feed) then we need to add a general purpose fertiliser or a nitrogen fertiliser instead to correct it - not Epsom Salts.



Why is this important ?

Because Epsom Salts are highly soluble and wash away quickly forming a pollutant elsewhere.

The article is aimed at large scale feeders of Epsom Salts - the odd teaspoon given to one or two plants every year is not going to add much to the level of pollutants around today.



What if we get yellow leaves ?

It does have implications for those of us who use a tomato type feed too early or in too high a concentration - we would be better off reducing the tomato feed and increasing nitrogen to correct yellow leaves rather than using Epsom Salts.

It is also a good reminder that too much fertiliser is bad for our plants and can actually poison them, rather than helping them!!

I've often read on here that when people get a little problem on their plants they immediately add more food even if it is the food that has caused the problem in the first place!!



What if we do have a real magnesium deficiency in our soil ?

Epsom Salts wash away very quickly - there are other sources of magnesium that will correct it AND stay active in the soil for much longer.




Food for thought !!!!!!!!!

[Two_Sheds]

What if we get yellow leaves ?

It does have implications for those of us who use a tomato type feed too early or in too high a concentration - we would be better off reducing the tomato feed and increasing nitrogen to correct yellow leaves rather than using Epsom Salts.

It is also a good reminder that too much fertiliser is bad for our plants and can actually poison them, rather than helping them!!

A good point, well made.

[gardenofeden]

good advice so far. all i would say is check the soil ph is correct before changing the nutrients just to rule it out. If the ph is too acidic or alkaline for the crop then it will have trouble pulling the correct proportion of nutrients from the soil, no matter if the correct amount is in there or not

[Flummery]

I've never added epsom salts to my watering can. I only feed tomato food sparingly. OK, I'm a tight-ass but I also think you can make the flavour of tomatoes very bland by forcing them on by over-feeding. (Is there such a word as 'emblanden' - make more bland? There should be!)

If I get the odd yellow leaf and it bothers me I take it off.