Orchid Focus Bloom and Grow

[Jagtazman]

Been using this two products as described on the bottles.
However went to an Orchid talk at local garden centre today and the guy taking advised to us Grow when you ha e flowers and Bloom to encourage the creation of flowers

However this is the opposite as what's on the products

Does anyone used these products and if so do you use as instructed on label or differently?

[Roberta]

The three numbers on the fertilizer are, in order, Nitrogen (N), Phosphorous (P), Potassium (K). Nitrogen encourages growth. Supposedly, lower nitrogen encourages blooms in the different formulations. Since fertilizer, in general, is one of the least-important factors in orchid culture (they just don't eat much, because they grow slowly) I suspect that for most purposes, a balanced (all 3 numbers the same) fertilizer for relatively hard water, or one with a lower middle number for pure water, is fine all year... using half to a quarter of the amount recommended on the label. For a commercial grower, perhaps tweaking the proportions at different times of the year will have a small effect. For the hobby grower, getting the rest of the culture - water, light, temperature, and air movement/media - correct will have a much more significant effect on growing and flowering success than the fine points of fertilizer proportions.

[rbarata]

This is in acordance with what Roberta explained: higher N => Grow / lower N => Bloom

I have read in many places that higher contents of P promotes better bloomings.

[Ray]

Assuming the plant is getting a complete diet, there is nothing that "promotes"blooming. Excessive nitrogen can quash blooming, and relieving that condition will "allow" it to happen. Read THIS.

[rbarata]

Very interesting, Ray. Thanks!

[Roberta]

Another reason that I have seen for adding phosphorous to fertilizer (to make the "balanced" 20-20-20, for instance) is to help counteract the alkalinity of "hard" water, since the phosphorous compounds are acidic. Based on my experience, it doesn't work, at least not with the robust hard water where I live... adding a few tens of parts per million of an acidic salt when there's a several hundred parts per million of persistently alkaline calcium carbonate in the water makes no measurable difference that I can see (measuring pH of the tap water and pH of the mixed fertilizer solution) I have RO now, so the MSU formulation gives a nice slightly acidic (5.5 or so) pH, but with tap water, the only way I could get the pH below 7.8 was to add a tablespoon per gallon of vinegar to the fertilizer water. So that extra phosphorous in the fertilizer? Based on Ray's assessment of what the plants need, and my observation of its other reputed effect, extra phosphorous doesn't do much.

[Ray]

There was an article about the importance of calcium in the most recent AOS magazine in which deficiencies can sometimes be linked directly to excessive phosphorus, so be careful.

High alkalinity is associated with high levels of dissolved solids; adding more will have little effect.