- Jun 10, 2006
- Reaction score
Higher value of Ca, Mg, Mn, Zn than N, P, K in leaves and soil....
Who is feeding the Paphs additional with the first elements?
15 years ago an orchid friend was feeding his Paph. niveum with more Na; the result: leafspan (niveum !) = 40 cm and the flower stalk was nearly 35 cm!
Poorly he can't remind the high of value from Na
Actually for Mn and Zn, I spray/drench with Dithane - Mancozeb quite frequently. I found out that when I do not do that, the leaves are a little bit bleached out. There were many reports from the horticulture industry about a "greening" effect of mancozeb.
Ca and Mg, with my base dressing of the substate, are supplied, and I use Mg sulfate from time to time. So far, Calcium is plentiful with the type of loess I use in my mix, from time to time a heavy spray with calcium ammonium nitrate, and that's done...
Na, I think that we tried to avoid that one for too long, but it is part of lifeforms anyway.
The keypoint of the whole story is that most of the "plant nutrition scientists" do not have any idea about specific genus or species requirement, so they simplified in their dumbness that all plants are equal and need the same...
It is of course completely wrong, try to give limestone to a sarracenia, or feed live sphagnum with osmocote, give to some proteas a high P fertilizer, use a corn fertilizer full strenght on a dendrobium cuthbertsonii, or anything like that and you end up with a big disaster. It just proove that different plants have different requirements, something that the fertilizer companies usually do not like to hear. They want their sales very simple, NPK, and cannot afford to do the cuthbertsonii specific fertilizer, the paph sanderianum specific fertilizer... It is understandable, but they cannot claim that one fertilizer will suit all.
Of course as well, you can lower the rate of fertilizer, but then you proportionally lower the micronutrients, and anyway if there is 5ppm Fe and 2 ppm Mn to 1 g of 20-20-20, when you use 0.1g, you get only 0.5 and 0.2, which can be far too low. The only way is to make home made, custom tailored fertilizers at home, something I did for many years, but I feel tired to do so sometimes. I am pretty sure that the plants are happier with specific fertilizers, but it is simply too much work. I would tend to think that the better way would be to have a combination like that:
- NPK only fertilizer
- Magnesium sulfate
- Calcium nitrate eventually
- Chelated iron
- Others micros including Zn, Mn, etc...
This would allow to keep the micros high, whilst lowering the NPK. With the commercial fertilizers, you must lower everything or nothing, therefore ending up with suboptimal levels of micros compared to the NPK...
Some paphs require this, some that, some hate this... One of the main reasons why things like paph papuanum - the zieckianum, not the violascens type..., wentworthianum, bougainvilleanum, etc... die in cultivation is that they have specific requirements for their nutrition. First, they accumulate iron to toxic levels very quickly, second they need a lot of micronutrients apart from iron, Mn, Zn, and Ni... Failure to do so, and the plants are bleached out and very sensitive to various rots and ailments.