OK, Silly Question

[2009zohsix]

We bought our first orchids about three months ago after doing some research here on the Orchid Board and on the AOS site. So far all are still alive and show new growth on each plant, even had one new bloom.

We adopted the "weekly, weakly" approach to fertilizing our new arrivals and purchased an MSU type fertilizer. The instructions on the fertilizer container says to mix one teaspoon per gallon of water, though it gives no frequency for fertilizing. Articles I've read on fertilizing says to use 1/4 strength fertilizer each week.

Should I be using the one teaspoon per gallon each week or 1/4 of that strength?

[Louis_W]

I would consider the dosage on the packaging a full strength dose. Common wisdom says that's a good concentration to use if you fertilize once month. Weakly weekly requires a more diluted dose so 1/4 teaspoon per gallon should be perfect. Personally I do about 1/4 strength every time I water.

[Ray]

The information you provided is insufficient to give a logical response.

Define "MSU type" in more detail. Is it the powder? If so, what is the formula. Is it the liquid from RepotMe? (If so, you paid way too much for water.)

If it's a 19%N powder, use 1/3 tsp/gal weekly.

If it's the 13%N powder, use 1/2 tsp/gal.

If it's the RepotMe liquid, they have dissolved the 13% granular in water and recommend 1 tbsp/gal. Since they don't specify the concentration of the solution (as required by law), there is no way to know how good their recommendation is...

[2009zohsix]

Originally Posted by Louis_W

I would consider the dosage on the packaging a full strength dose. Common wisdom says that's a good concentration to use if you fertilize once month. Weakly weekly requires a less diluted dose so 1/4 teaspoon per gallon should be perfect. Personally I do about 1/4 strength every time I water.

Thank you Louis. That makes perfect sense.

---------- Post added at 06:01 PM ---------- Previous post was at 05:56 PM ----------

Originally Posted by Ray

The information you provided is insufficient to give a logical response.

Define "MSU type" in more detail. Is it the powder? If so, what is the formula. Is it the liquid from RepotMe? (If so, you paid way too much for water.)

If it's a 19%N powder, use 1/3 tsp/gal weekly.

If it's the 13%N powder, use 1/2 tsp/gal.

If it's the RepotMe liquid, they have dissolved the 13% granular in water and recommend 1 tbsp/gal. Since they don't specify the concentration of the solution (as required by law), there is no way to know how good their recommendation is...

Thank you Ray. It is 13%N powder, so I'll use 1/2 tsp/gal.

[Ray]

Originally Posted by 2009zohsix

Thank you Ray. It is 13%N powder, so I'll use 1/2 tsp/gal.

Basically, a lot of folks have found that applying a solution bearing 75-125 ppm N weekly seems to be a good level.

If you divide 8 by the %N in the formula, the result is the teaspoons/gallon for the middle of that range, allowing for rounding to make measuring easier.

The MSU RO formula is 13.2% N, so 8/13.2=0.6, making 1/2 or 3/4 perfectly acceptable - but do not think for a moment that “more” will equate to better growth or flowering.