Fertilizer Change During Flower Spike

[MateoinLosAngeles]

Most of the evidence shows no benefit to changing fertilizer concentrations during blooms/vegetative growth, etc.

The consensus is to fertilize weakly and often, especially for Phals, which makes sense. Calcium is important, but you don't need a concentration higher than what comes in the MSU. Besides, you could run into mixing/precipitation issues. I personally use K-Lite and fertilize at 25 ppm N.

I fertilize with every watering in the spring and fall; during winter, I mostly water with plain water, and in summer, I fertilize at every other watering or less. During winter I may mix some RO water with tap water which adds calcium carbonate.

Calcium benefits all orchids, but it's not particularly essential for Phals; rather, orchids that are more frequently lithophytic seem to appreciate it more. Too much calcium could make the medium too alkaline, and Phalaenopsis seem to prefer more acidic conditions; some growers say they experience improved growth when lowering the pH of their fertilized water, although I haven't tried it myself.

I add slow-release dolomite lime or marble chips to Oncidiums, Paphs, and European terrestrials. They all seem to benefit from that, even need it to put out strong growth. However, I don't necessarily supplement it (beyond what's in K-Lite) for any other plant and none have shown signs of deficiency.

[alecStewart1]

Originally Posted by MateoinLosAngeles

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I fertilize with every watering in the spring and fall; during winter, I mostly water with plain water, and in summer, I fertilize at every other watering or less. During winter I may mix some RO water with tap water which adds calcium carbonate.

I know there's more advanced discussion going on here, and I'm not the most experienced, but sometimes it's not wrong to keep it simple.

What MateoinLosAngeles said is basically what I've concluded for my orchid culture.
Pretty much all of the orchids I have are ones that want to be wet and then left alone to let their medium dry. In winter, watering less is necessary because you could say orchids are like people; who likes being wet and cold?

As for fertilizing, since I mostly have Vandaceous orchids and some Dendrobiums that are in sphagnum moss, so come spring time I fertilize every other watering to avoid unwanted mineral build up.
For the orchids in bark or looser mediums that won't hold on to water like moss does, I'll water every watering.

The above is in line with what Ray mentioned.

The only other thing I've seen is "if the orchid is growing, you should give it fertilizer." So an example would be Neos, they're just chilling for the winter and not growing so I just water them with plain water. My Phal on the other hand is growing new leaves and roots, so I fertilize it. I'll just use K-Lite for fertilizer at the recommended amount, maybe I mix in some Kelpak or Quantum Total from time to time or some calcium supplement if need be.

I think the only times I've seen people need to add more of something like nitrogen or calcium or whatever else is when something funky is happening with your plant (bud blast, abnormally stunted growth, etc.) and the rest of the culture is fine, or if you have a plant that wants more calcium than the others or something to that extent.

Maybe there's a super optimized method of doing things, but I don't grow anything professionally and have so far haven't had many problems following the basic advice, so why give myself more things to think about than I already do?

Probably wasn't the simplest explanation, but...yea.

[Bloomer001]

Ray, I just saw your question. I measure the ferts with a gram scale. I use .625 grams of K-Lite per liter of water. And half (.312 g) of Miracle Gro per liter of water. I try to get 75 ppm for each solution. Each orchid gets approx. 1/3 liter on the pour through watering day once a week. Mid-week (if they are dry enough) I spray the top soil with a 75 ppm fert solution from a spray bottle (this dries out faster than the pour through.)

Note: the directions on the K-Lite bottle say to use .57 grams of fert per liter to get 75 ppm. I don't know if my math is wrong, but I took a pic of my formulas to get 75 ppm per liter.

[Ray]

Originally Posted by Bloomer001

Ray, I just saw your question. I measure the ferts with a gram scale. I use .625 grams of K-Lite per liter of water. And half (.312 g) of Miracle Gro per liter of water. I try to get 75 ppm for each solution. Each orchid gets approx. 1/3 liter on the pour through watering day once a week. Mid-week (if they are dry enough) I spray the top soil with a 75 ppm fert solution from a spray bottle (this dries out faster than the pour through.)

Note: the directions on the K-Lite bottle say to use .57 grams of fert per liter to get 75 ppm. I don't know if my math is wrong, but I took a pic of my formulas to get 75 ppm per liter.

The K-Lite measurement is right on, but why AND Miracle Gro? The K-Lite alone - or Miracle Gro alone, if you've calculated it correctly - are sufficient.

[Bloomer001]

I wrote that clumbsily. They are separate solutions. One liter of water has .625 grams of K-Lite. The other liter of water has .312 grams of Miracle Gro. Each 1 liter solution contains 75 ppm of Nitrogen.