Soaking before fertilizing?

[Ernesto]

At an orchid show in February a vendor told me to always soak my orchids before fertilizing lest I risk root tip burn. My weekly watering routine now consists of allowing my plants to soak in water for awhile while I get other tasks done (usually water changes for my fish tanks, since I’m already working with water) and then fertilizing, allowing the fertilizer water to run through the pot. They all get monthly flushes as well.

However, as I’ve had a lot of time home lately my collection has grown and I’m looking for ways to make watering more efficient. Now I’m wondering, can I save myself a step and just soak in fertilizer water, while still doing the monthly flushes?

 

[troy]

I would not water before fertilizing. Root velemin only absorbs so much..... dilute your fertilizer to 1/4 of recommended strength and rinse through pot for fertilizing... then if you want to prevent any fertilizer salts build up, rinse pot after fertilizing with pure water. Don't soak your pot unless you know your plant lives below a high water line for part of a year, that's what I do, also I always check geographical location habitat my plants live in, to try and keep it alive

 

[CarlG]

If you are really worried about root burn, fertilize normally, THEN flush the pot perhaps a half hour later. The velamen is adapted to an environment where the first burst of water, for example in a rain fall, is nutrient rich and so is rapidly absorbed, while subsequent flow is nutrient poor, and so is pretty much not absorbed. (There was an article in Lindleyana on this topic quite some years ago, but I don't have the reference handy).

I have heard, perhaps incorrectly, that John Leathers, a well-known Dracula grower, fertilizes, and then hoses his plants down afterwards to flush any non-absorbed fertilizer.

 

[Ray]

It think the “double dose” treatment, no matter what the order, is a waste of time.

I have found that somewhere between 75 and 125 ppm N, applied over the course of a week, Is good for my plants without fear of burning. My greenhouse in PA was watered and fed about every other day at 25 ppm N. The plants on my deck in NC get fed weekly at 100 ppm N. For MSU WW formula @ 19% N, a half teaspoon/gal is about 118 ppm N. For MSU RO or K-Lite, 2/3 teaspoon/gal is 100 ppm N.

I also think that flooding the pot with a good water breaker is superior to immersion soaking, as it flushes mineral deposits and small decomposition fragments out of the pot while saturating and aerating the medium.

 

[MaxC]

I can only echo the sentiments above for my Phragmipediums. Growing indoors, I am watering daily for almost all my phrags and add fertilizer aside from a monthly flush. My daily regimen is 25ppm K-Lite, 200ppm Green Jungle and bi-weekly application of KelpMax 1 tablespoon per gallon. Once a month I give a treatment of Inocucor. I am going into month 4 of this specific regimen and have had no leaf tip burn. This includes seedlings and mature plants. I recently repotted a large plant and it had over 20 active growing root tips and at least 6 new growths. Without a larger controlled experiment my evidence is anecdotal but I would say, "so far, so good."

There's a good book for cultural reference, "Orchid Species Culture: Pescatorea to Pleione" by the Bakers that costs about $20. It contains in situ information for Phragmipedium species (temperature, hours of light, blooming months, etc.) and can be helpful in guiding you with fine tuning your culture and thinking about conditions these plants would have come from.

 

[littlefrog]

One of the best growers I know fertilized phragmipediums at a rate that I thought would be impossible. Plants looked great and never had tip burn. I can't grow them cleanly at 1/4 the concentration he used. Once I learned that I've stopped worrying so much about exact numbers and schedules.

I aim for 75-100ppm nitrogen (MSU formulation, which is basically "K-not lite"), constant feed no matter what time of year. I water a bit less in the winter, but same fertilizer rate. I've never watered with clean water before or after fertilizing. Ever. And I've been doing this for 30+ years. Still learning, but I barely have time to water once. I do occasionally (on no particular schedule) skip fertilizing for a regular watering or two.

 

[troy]

Bill Thoms gave a speech and said feed your plants, don't starve them to death. For more info about you should feed your plants, contact bill thoms at bulbophyllums.com

 

[gego]

I was feeding at 50 ppm N every time I water the growth was okay. Then I saw really good healthy plants then I wonder why mine are not like that. So I experimented with 10 healthy plants. I started 100 ppm N, I saw an immediate growth, leaves were widening and thicker. After 8 applications, I can see roots are still healthy with long white tips. Then I increased to 200 ppm N but P and K stayed at 75 ppm. I saw some real growth. Not going back to 50 anymore.

 

[Tony]

I was feeding at 50 ppm N every time I water the growth was okay. Then I saw really good healthy plants then I wonder why mine are not like that. So I experimented with 10 healthy plants. I started 100 ppm N, I saw an immediate growth, leaves were widening and thicker. After 8 applications, I can see roots are still healthy with long white tips. Then I increased to 200 ppm N but P and K stayed at 75 ppm. I saw some real growth. Not going back to 50 anymore.

How often are you watering at that strength?

 

[Ray]

When I used 25 ppm N, I was watering - at least - every other day. I now use 100 ppm N and that is about one a week, occasionally more frequently.

 

[gego]

How often are you watering at that strength?

This is feeding weekly but I water twice a week. Watering is only to re wet the potting so salt will not solidify. I flush with low ppm water before feeding again. To minimize salt, I use 100 ppm urea to make it 200 ppm total.

 

[Brabantia]

It seems to me that over time some growers are moving away from the nitrogen concentrations that had been recommended on this forum by Rick Lockwood. Was it insufficient? what problems have you encountered while feeding weakly but often?

 

[gego]

The insufficiency, in my experience was actually causing discolored leaf tips, which I thought I was overfeeding. It was actually deficiency. But I would like to emphasize that when you feed, you should also have other conditions satisfied, like light , temp and air exchange. I also find that growth and appearance of leaves are way better under real light, sunlight.

 

[Russ1992]

It think the “double dose” treatment, no matter what the order, is a waste of time.

I have found that somewhere between 75 and 125 ppm N, applied over the course of a week, Is good for my plants without fear of burning. My greenhouse in PA was watered and fed about every other day at 25 ppm N. The plants on my deck in NC get fed weekly at 100 ppm N. For MSU WW formula @ 19% N, a half teaspoon/gal is about 118 ppm N. For MSU RO or K-Lite, 2/3 teaspoon/gal is 100 ppm N.

I also think that flooding the pot with a good water breaker is superior to immersion soaking, as it flushes mineral deposits and small decomposition fragments out of the pot while saturating and aerating the medium.

But what if ones water isn't as clean as yours? I need to use water from the tap that's 275+ ppm and then when you add msu forget about it.

 

[Ray]

But what if ones water isn't as clean as yours? I need to use water from the tap that's 275+ ppm and then when you add msu forget about it.

The concept still applies - maybe even more so. In my mind, there are two processes to deal with: saturation and ion capture, and both have limits.

Scenario 1 - one watering with pure water and fertilizer: the roots become saturated with the solution and as many nutrient ions as possible are captured.

Scenario 2 - initial, plain, pure water irrigation, followed up with fertilizer solution: the roots become saturated, reducing the absorption of the fertilizer solution, so fewer ions are captured.

Scenario 3 - one watering with “275+ ppm” water and fertilizer: the roots become saturated with the solution and as many dissolved mineral- and nutrient ions as possible are captured.

Scenario 4 - initial, “275+ ppm” water irrigation, followed up with fertilizer solution made with the same water: the roots become saturated and capture as many of the dissolved mineral ions as possible with the first watering, reducing both the absorption of the fertilizer solution at the second, which already allows fewer ions to be captured, but the sites available to capture more are already occupied, so even fewer nutrient ions can be captured.

 

[Russ1992]

The concept still applies - maybe even more so. In my mind, there are two processes to deal with: saturation and ion capture, and both have limits.

Scenario 1 - one watering with pure water and fertilizer: the roots become saturated with the solution and as many nutrient ions as possible are captured.

Scenario 2 - initial, plain, pure water irrigation, followed up with fertilizer solution: the roots become saturated, reducing the absorption of the fertilizer solution, so fewer ions are captured.

Scenario 3 - one watering with “275+ ppm” water and fertilizer: the roots become saturated with the solution and as many dissolved mineral- and nutrient ions as possible are captured.

Scenario 4 - initial, “275+ ppm” water irrigation, followed up with fertilizer solution made with the same water: the roots become saturated and capture as many of the dissolved mineral ions as possible with the first watering, reducing both the absorption of the fertilizer solution at the second, which already allows fewer ions to be captured, but the sites available to capture more are already occupied, so even fewer nutrient ions can be captured.

This makes total sense, and to be sure, you are THE man so I trust your judgment. I have a friend who used to be big in the paph world say around the 80's - 90's and his name is Kevin Porter. He told me to do the flushing first and then the fert but I agree with you ultimately Ray. BTW do you sell plants? It looks like you did in the past. I'm rather new to the hobby.

 

[Ray]

This makes total sense, and to be sure, you are THE man so I trust your judgment. I have a friend who used to be big in the paph world say around the 80's - 90's and his name is Kevin Porter. He told me to do the flushing first and then the fert but I agree with you ultimately Ray. BTW do you sell plants? It looks like you did in the past. I'm rather new to the hobby.

I certainly wouldn’t say I’m “THE man”, but I do like to analyze things with a scientific perspective…

I used to sell plants and over 300 different orchid-growing supplies, occupying about 5000 square feet of warehouse space, but prior to retirement, I sold off all but about a dozen plants I wanted to keep, the greenhouse and all of the related equipment, and stopped restocking supplies as they sold out. Moved here and reopened with 3 products (KelpMax, K-Lite, Quantum-Pro) occupying a 75 square foot room off my garage. I’ve since added a few pesticides and miscellaneous items, but it’s all still in that room.

The only time I have plants for sale is the occasional division of my own plants, or if I got a deal on something I wanted, so have multiples.

 

[NYEric]

I don't flush but rather regular to light water before applying fertilizer/feed. That is from culture tips from Terry Root (OZ).

 

[southernbelle]

It w

I was feeding at 50 ppm N every time I water the growth was okay. Then I saw really good healthy plants then I wonder why mine are not like that. So I experimented with 10 healthy plants. I started 100 ppm N, I saw an immediate growth, leaves were widening and thicker. After 8 applications, I can see roots are still healthy with long white tips. Then I increased to 200 ppm N but P and K stayed at 75 ppm. I saw some real growth. Not going back to 50 anymore.

It will be interesting to see how that affects bloom. Hadley Cash says to promote bloom in Paphs:
“Mid-Sept/mid-Oct shift to bloom booster type (low nitrogen). Or, ⅓ strength normal fertilizer for 2-2.5 months then use summer fertilizer at 1/2 teas/gal.”
The idea is if you are pushing growth with nitrogen you are less like to get bloom.

 

[Ray]

The idea is if you are pushing growth with nitrogen you are less like to get bloom.

Absolutely, but it is the MASS of nitrogen taken up, not the concentration, per se.

In the wild, the supply of nutrition is fairly steady, albeit very low in concentration. In a semi-hydro pot, the situation is similar, but in traditional culture, we tend to feed more heavily/less often.

I look at it as the healthy diet of several, smaller meals versus the gluttony of a few, large ones.