How much nitrogen should cattleyas ....
 

potted in 100% lava rock be receiving at every watering?

I've read online that cattleyas potted in bark should receive a high nitrogen fertilizer.

What you do pot your catts in and how much fertilizer do you apply at every watering?

Hmmmmmmmmmm...thanks.:waving

I wish there was a source for recommended nitrogen levels for each genus. Maybe this thread will uncover one! Using Rays nitrogen calculator I recently discovered that I'm not providing enough.

The articles I've read only specify the nitrogen content when catts are potted in bark. I pot mine in 100% lava rock. I recently switched to 20-20-20 and the instructions indicate 2 tablespoons per gallon. I have been doing this for all my orchids and they are growing like crazy-especially the cattleyas. Pretty much most of them have new growths and lots of new roots, but I fear that I'm using too much fertilizer. I don't want to damage the plants.


I haven't noticed much change in my vandas, but I have also noticed considerable growth in my phals.

WOW 2 tablespoons comes out to like 1050 ppm N. If you meant 2 teaspoons thats still high...like 500 ppm. Check out Rays fertilizer calc.

Fertilizer PPM Calculator

No,

it says two tablespoons.

Holy smokes! The most I've seen is 1 teaspoon per gallon.

So i guess from your reactions, I shoudl DEFINITELY cut back, A LOT, no? :shock::shock::shock::shock::shock::shock::shock:: shock::shock::shock::shock::shock::shock::shock::s hock::shock::shock::shock:

Ok, I'm freaking out.

I went outside to check the package, and yes, it says 2 tablespoons per gallon. I went to a nursery down here to buy some orchids for a gift and that's what was recommended. I used to use MSU, but I ran out, so I thought I'd try this.

Have I damaged the plants? I only fertilize once a week. I've noticed that some of the catts have those gummy drops like phals get, and their leaves are very upright.

How can I fix this?

just flush the pots really well with water if you are worried :)

And how many Mairol (solid or liquid) in your fertilizer solution are you using in term of nitrogen concentration and what is your distributions frequency in growing period? Many thanks in advance for these precisions.