Input on orchid and magnesium

[Dazed]

I have no idea of when to give, how do I know the orchid needs it, if to give, how to apply, which type of orchid needs it more, which type of magnesium, are there side affects for giving too much or too little, what method to use to apply it?

[Gage]

I will tell you what I have learned from some of the experts in South Florida. Apparently high phosphorus in fertilizer tends to bind up trace elements such as magnesium, making it difficult for the plants to absorb these needed nutrients. So it is recommended to give magnesium sulfate (epsom salts, sold cheaply at pharmacies) at 1 tablespoon per gallon either alone, or mixed with a phosphorus-free fertilizer such as 10-0-10. You can do this monthly, or twice monthly, between fertilizings. Hopefully others can chime in with more info for you!

Gage

[Dazed]

Well heck I was doing it and didn't even realise it, I grew up putting epsom salts to our plants, never knew why, just that it made them flourish. Though I've always wondered if you can over do it? How do you know there is too much in the plant or can it regulate the intake by itself?

[Gage]

I've never heard of magnesium overload. The only thing that might be an issue is salts building up in the growing media, but that would be a culture issue.

[orchid-man]

An old tomato grower always told me that potash and magnesium had to be blanced for a good crop of tomato.When questioned about this in relation to our orchids he said" what do you want to produce ,plant growth(foliage),flower or fruit (seed pods).?

When I said 'flower' his reply was OK you want fruit! where do you get fruit (seed pod) from ?answer flowers .
All plants need magnesium for reproduction - lack of magnesium = less flowers = less seed.

These days I add magnesiun to all my fertilisation at the rate of about three spoons per 100litres of water, in the summer(growing season) they would get this 3 times per week. Result - excellent growth,dark green foliage,very sturdy growth and heaps of spikes and flower -the best flowering so far.

If too much magnesium is applied the side effect that is most noticable is very young plants flowering when they are too small. , is that a bad side effect ?

[Halloamey]

If it works for you then fine but scientifically this line of reasoning in flawed. For reproduction in general or blooming, plants need higher potassium thats why you will find bloom boosters with higher levels of potash (it is experimentally proven that plants fed with higher potash produce more flowers, which are bigger and better and last longer). On the other hand magnesium is the core of Chlorophyll molecule. Less magnesium = less chlorophyll = less photosynthesis = less plant growth in general. The results you have achieved also corroborate this, more Mg during growth, means more growth, means more energy for reproduction i.e. blooming. Interesting to know about the early blooming of plants with higher use of Mg, had never heard that before.

An old tomato grower always told me that potash and magnesium had to be blanced for a good crop of tomato.When questioned about this in relation to our orchids he said" what do you want to produce ,plant growth(foliage),flower or fruit (seed pods).?

When I said 'flower' his reply was OK you want fruit! where do you get fruit (seed pod) from ?answer flowers .
All plants need magnesium for reproduction - lack of magnesium = less flowers = less seed.

These days I add magnesiun to all my fertilisation at the rate of about three spoons per 100litres of water, in the summer(growing season) they would get this 3 times per week. Result - excellent growth,dark green foliage,very sturdy growth and heaps of spikes and flower -the best flowering so far.

If too much magnesium is applied the side effect that is most noticable is very young plants flowering when they are too small. , is that a bad side effect ?

[Kmac]

Interesting thread...glad I saw this.

[Brutal_Dreamer]

Cool thread. I'll be interested to here more opinions on this topic. cheers, BD

[CVHorticulture]

I would like to second what gage said about with a few caveast. Fertilizer, 10-0-33 (potassium nitrate) is pretty available and reasonably priced, $35/25lbs. I rotate my fertilizing, to avoid the ionic lockup associated with P and Mg binding/ inhibition. So if i fertilize with a balanced fertilizer, then the next time, the plants get fed with (2tsp 10-0-33 plus 1Tbs of MgSO4)/gal.

[Lester Poole]

Magnesium is the essential driving molecule in chlorophyll. Plants treated with extra magnesium (Epsom salts) will quickly show their appreciation with improved foliage color. Just do not over do it as you can lock up Calcium by over application [an issue in other parts of the country, but not in calcium rich Florida aquifers. In the summer I like to water my plants well the day before or the morning of my fertilizing. This lowers the chances of burning new root tips as the day progressess. I know of some growing practices that lighly mist orchids after they have been thoroughly fertilized to rinse fertilizer out of new growths. This is an especially helpful practice in the heat of the summer when new tender growths can cup hot fertilizer water and may show damage due to the heat build up against sensitive tissue.