Grocery store phal/roots

[gingersmommy]

Okay, my humidity meter came and I put it in my orchid room today at lunch. It is five hours later and it is at 70% humidity. I think the only thing I have to perfect is the watering. I water once a week, however, I think the ones in smaller pots may need every 5-6 days. Did that a few times but I am more afraid of overwatering than under. They all seem like they are thriving. No spikes just yet - but I am hopeful!

[rbarata]

Those temps and that humidity seems fine.
Do you fertilize? If so, how much?

[gingersmommy]

Yes, I fertilize with Feed Me, which I guess is base don the Michigan formula (?). I fertilize every time I water. Directions say 1 oz. per gallon (2 Tbs.), but I use probably 2 tsp. I also use a very dilute probiotic solution, forget the name of it.

They all look pretty healthy. This is going to be my year!!! I'm going to post a million pics on here!

[estación seca]

With your humidity and temperatures the roots should stay fine for weeks even if you don't water.

What are the numbers on the fertilizer label? Is it a powder or a liquid?

2 teaspoons / 10ml of dry powder per gallon / 3.78 liters might be enough to kill orchid roots with just one watering. Most people using a dry powder Michigan State University (MSU) formula will use between 1/8 and 1/2 teaspoon per gallon of water, from 1-4 times a month.

[gingersmommy]

Originally Posted by estación seca

With your humidity and temperatures the roots should stay fine for weeks even if you don't water.

What are the numbers on the fertilizer label? Is it a powder or a liquid?

2 teaspoons / 10ml of dry powder per gallon / 3.78 liters might be enough to kill orchid roots with just one watering. Most people using a dry powder Michigan State University (MSU) formula will use between 1/8 and 1/2 teaspoon per gallon of water, from 1-4 times a month.

Hi, I use the liquid Feed Me.

FEED ME! MSU Orchid Fertilizer - RO/Rain/Tap Water - 16 oz (Pint)

[estación seca]

If their product really yields 125 parts per million of nitrogen when 1 ounce / 2 Tablespoons / 6 teaspoons / 28ml of their liquid is diluted in 1 gallon / 3.78 liter of water, their label numbers are wrong. MSU powder is 13-3-15 and they're diluting it with water, so the numbers on their container should be lower.

Most people would use fertilizer with 125 ppm N about once every 2-4 weeks. If it really does yield a final concentration of 125 ppm nitrogen, that could damage roots if you use it every watering. This might be your problem, because fertilizer damage to roots looks like what you have.

People use very low amounts of nitrogen if they fertilise at every watering, in the range of 10-25 ppm. If you used 1/6 the amount they recommend, which would be 1 teaspoon / 5ml of their liquid per gallon of water, you would have about 21 ppm N, which would be reasonable for use at every watering. A half teaspoon would give about 10 ppm N, also a reasonable amount to use. But as I mentioned, I think their numbers are wrong.

Buying diluted fertilizer means you're paying a lot of money for water. I buy a powder formulation of MSU and mix it myself. Depending on the kinds of plants I'm fertilizing, and how they're potted, I use between 1/8 teaspoon per gallon (plants in S/H, every watering) to 2 Tablespoon per gallon (bare-root Vandas, every 5th watering.)

There is a nitrogen calculator on the First Rays Web site in the Free Information section. You input the N number on your fertilizer and it tells you how much to add to water to get the desired concentration of nitrogen, in ppm.

[gingersmommy]

Thank you. I am almost of of the liquid; I will finish it up and purchase the power.

What is it that you see that indicates root damage from fertilizer?

[rbarata]

First, the most probable parameters that could cause root issues (temp and humidity) are ok.
Second, they look dry and burned and it happened fast.