Feeding the Masdies
 

Since many years I search on the Net what is a good regime for feeding the Masdevallia.
I read the most various opinions and often very diverging.
This last in date from a renowned producer (on its site):
"Fertilizer: as with most orchids the mantra is “weekly, weakly”. We fertilize once a week at a low rate of 100 parts per million nitrogen".
Is that a low rate ??
If the maths are correct this mean 750 to 850 ppm of total salts (in function of the percentage of Nitrogen in the fertilyser). It seems to me a little bit high :).
On Wiki I read: They should be fertilized with a half-strength mixture of a balanced fertilizer once a month and a high nitrogen fertilizer can be used for single applications in the spring and fall.
How high is a full strengh ??
Here in Belgium a nursery recommend 65 ppm N from a 13_3_15 Ca Mg one time per week. I have tested ... roots burn!
So in touch with your experience can you recommend me a level of feeding and a frequency which would be completely allowable to feed Masdevallia without the risk of burning roots or seeing appearing black stains on leaves. Thank you in advance.

That does seem high to me, too. I only have a couple of Masdies, and am still working out the fertilizer, but what I have mostly read here seems to be about 1/4 strength (of more typical "feeders", I guess).

Hopefully more experienced Masdie growers will chime in.

Apparently I have sixty-four of them now. Just came home with a couple today and decided to count.

Anyway they are super light feeders. I use K-lite (12-1-1-10Ca-3Mg) like I do on all my other orchids. I do it once every two weeks or so, at about 60ppm.

I also foliar feed them KelpMax every two/three weeks (separately) and feel like this is an awesome thing for them. I've pulled plants out of their pots after having them for a few months under this regimen and can see the difference right in front of me with root quality.

Note - I have two mounted Masdies, and probably six or so that are still left in bark from when I bought them, but all the rest are in premium NZ Sphag in clay pots.

I only have one Masd and when I first had it I fed it too much. It got 3 spindly flowers. Last spring after reading that some people use slow release fertilizer, I put just a little around the plant. It looks very healthy but hasn't bloomed yet, so I'm not sure of the results.
This one is Andean Prince. I'm not sure that it is a good bloomer.

I feed every other week 1/2 strength year round. In the winter the feedings are spread out a little more due to the humidity and the moisture retention from the cooler temperatures.
I'm trying some slow release on some of the plants to see how they fare.

I put a little slow release on mine last year and it grew well but still hasn't bloomed. I don't know if it is just the particular masdie I have, but I haven't been too pleased with it. It hasn't bloomed well. I also have to constantly watch for scale.

I've had good luck with masdies although I had to give them to a friend with a greenhouse to foster for me when I moved to being a snowbird in Costa Rica and couldn't ask my sons to care for them over the winter. I fertilized 1/2 strength every other week or 1/4 strength weekly.

Thank you all for your responses. But ... for me when you speak strength for a fertilyser that say nothing for me if you are not saying me how many is the full strenght and which fertilyser you use. For me a 13/3/15 (or other)
at a concentration of 0.5 gr/L it is more eloquent.

It's impossible for everyone to do the math for each other, as so many products are different.

Here, you can use Ray's calculator to determine what works for you:

Fertilizer PPM Calculator

I don't have any masdevallias. I have many cattleya, and various phalaenopsis, paphiopedilum etc. I use RO water with added nutrients at every watering. The concentration of added nutrients is usually in the range of 100 ppm to 300 ppm. 100 ppm equals 0.1 gram per liter.

I kind of rotate, using synthetic orchid powdered fertilizer one week, then worm tea, then plain water, etc. and have had pretty good results. Of course it's impossible to say that I'm getting the best possible.

I feed with every watering at 10-20 ppm N (figure out how much that is for your fertilizer using Ray's calculator; link posted earlier). My plants really like Neptune's Harvest fish/seaweed, but I find it feeds a lot of algae as well. So I alternate with K-Lite and even some PlantProd 25-10-10. But keep it really low - 10 ppm N is less than 1/10th the recommended strength on most commercial fertilizers - after all, fert manufacturers won't make any money by telling you to use less of their product.

The fertilizer number e.g. 10-10-10 is expressed as percentages. The first number is the percentage of nitrogen. So a 10-10-10 fertilizer at 100 ppm is giving 10 ppm of nitrogen.

David, I disagree with you there. A lot of salts also contain waters of hydration, even when they appear to be completely dry. These bound water molecules add to the weight of the fertilizer (and the numbers are as a % of weight for each of the 3 main elements), but they don't add to the ppm. So most likely, 100 ppm of a commercial 10-10-10 fertilizer will contain more than 10 ppm of nitrogen.

With liquid fertilizers, water plays an obviously bigger role. Most liquid formulations are 40-60% water; organic fertilizers are even more dilute. However, the three N-P-K numbers still refer to the % of the bottled product, not just its dry weight. And with organic fertilizers, some ingredients are not dissolved salts, so they won't register on the TDS meter. However, they still contribute to plant nutrition.

If you take a 10-10-10 fertilizer and dissolve 0.1 gram of it in a liter of water then you will have a solution containing 10 ppm of nitrogen.

I feed my collection(couple of hundred I think) with Akernes Rain mix at 1/2 gram litre at every watering, no flushing, no hassle. Comes out about 550-600 microsiemens, I don't know what root burn is.

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Do you feed with this concentration on humid roots?
Living in Belgium you will easily understand that I have already used RainMix fertilyser with rain water. I am sure that used at 0.5 gr / L roots are burned. I am not the only one to have made the experience. But on already wet roots or non-displayed to light maybe to feed at this concentration it's possible. Please, explain me exactly how you do because I am not the only one be to be interested. This is a subject about which I have discussed many time with Kenneth. Many thanks in advance.

I use Rain Mix at 0.5g/L on Masdies with no problems. However I keep my masdies always moist, so the roots are rarely completely dry when water. It could be different on completely dry roots.

I used to use a different fertiliser and my mixing rate worked out at a higher concentration. I had no problem with that on Masdies either, though I didn't use it with every watering.

Without reliable data you can never be sure.
I watered my Masdies only with rainwater. I constantly check the electric conductivity with a meter. Pure rainwater in the city measures 15-60 microSiemens. I add fertilizer for Masdies up to 300 microSiemens. If kept constantly more or less humid and in growth, the plants can stand a higher concentration. Mounted plants and dry plants need lower concentration.
To the contrary Cattleyas get 600- 1000 microSiemens in summertime.
Any balanced fertilizer suited for orchids suits for Masdies. I would not calculate concentration but measure. I recommend to avoid well water in the long run. I strongly recommend to buy a meter.
Happy growing!