Switching back to a balanced fertilizer.....

[tucker85]

In 2010 I started using a MSU type, low phosphorus, fertilizer on the recommendation in a book I had read. In the fall of that year my plants were doing very well but I noticed that I wasn't getting as many flowers as normal. So in the begining of 2011 I switched back to a balanced 20-20-20 fertilizer. Now the fall is here an I'm getting significantly more flowers than last year. In fact my Cattleya Jenmanii had two flowers per stem last year has 5 flowers per stem this year. My other orchids are showing the same kind of improvement. I know that the fertilizer that works best for me may not work for someone with a different water quality or culture techniques. I also understand that there are many variables that can affect the way a plant flowers other than the fertilizer it's getting. But for now I'm going to stick with a balance fertilizer.

[Cym Ladye]

Tucker,

I am really glad to see someone else observing this characteristic with the MSU fertilizer. At the first show this winter, I noted several Cymbidiums grown by one of our club's best growers were heavy in dark foliage and sparse on spikes in proportion to the size of the plants. I took another one of his plants down to Santa Barbara for a possible AOS or CSA award and placed it in my display. The leaves were very weak, the color dark green and again, only two spikes of lower flower count than genetically one could expect for the cross for the 8 bulbs or so in the pot.

His plants are grown in a very large commercial type greenhouse with good light, but the benches look like a jungle! I felt instinctively when I viewed his growing area, that he was over fertilizing with therefore too much nitrogen, which he admitted he probably was doing. However, I have seen similar results from another Cymbidium grower using the same formula.

I switched over to the 18-4-22 formula this spring on my Cymbidiums on a trial basis. I did not check my ppm until August and then discovered I was over-dosing due to the calibration of my water system. Fertilizing every two weeks probably evened things out to some degree.

However, what I noted in early September were HUGE growths, larger than I had seen in a long time, maturing to easily bloom with a heavy spike this season and additional small growths emerging from other bulbs in the pot. Added to that, the leaves seemed weaker than I would want. At his time, I backed off to 125ppm nitrogen every two weeks, and the weather has started to cool off. Both of these steps should start to slow as well as harden off the growths.

I considered, as you are doing, going back to a balanced fertilizer or even a low nitrogen formula, but I think I am more tempted to cut the ppm even more, or eliminate fertilizing my blooming sized plants altogether until early spring or the occasional warm, sunny days we get here in the winter. I will keep my small seedlings on the 125ppm nitrogen until cold wet weather sets in and I stop needing to water because of rain and low temps.

I know Ray has far more experience with the MSU formulations and I would welcome his input on this subject.

CL

[ronaldhanko]

Thanks very much for this post! I'm not as scientific as some but had considered switching to the MSU fertilizer and now will just stick with what I am using. Excellent and informative post.

[silken]

Interesting info. I use MSU most of the time and had just recently read that there is no need to switch to a bloom booster formula prior to getting spikes. I do occasionally throw in a feed of Schultz bloom booster with high phosphorous cause I sure don't want to miss some flowers if the potential is there. After reading this I think I will just stick to what I'm doing.

[Ray]

I have been using the Greencare Orchid Special for RO (the original "MSU" fertilizer) exclusively for about 8 years now, give or take, and I have consistently gotten great growth and blooming.

Knowing full well that there are a zillion variables in orchid growing, it's hard for me to 1) understand why that formula would not be good for maintaining healthy plants, and 2) have any idea what the issue might be.

Tucker, I have heard that folks in some parts of Florida and (I think) Arizona or nearby, have had success with a modification to the original formula. Let me see if I can find out more about it.

[tucker85]

Thanks Ray. Some growers have good results with Peter's Excell cal mag which is a MSU type formula but 20-20-20 seems to be working very well for me.

[Cym Ladye]

Ray,

I hope my post did not infer that my Cymbidiums were not growing well! Quite the opposite! They are growing better than they ever did before with other fertilizers. My concern is the weakness of the leaves (accompanied by the dark color), and the push of growth at the possible expense of flower spikes and flower count that I have noted with other growers and the beginning of the same with mine.

The 18-4-22 formula I am using is not the original MSU packaging but is formulated using their criteria by a local commercial fertilizer company, much as I suspect yours is too. Perhaps I am looking for perfection in production but I am seeing signs I have not seen before.

Bottom line is I think the application rate is the problem in all cases. That is why I gave my ppm nitrogen amounts. I have decided to continue to use MSU until I drop off during the winter, but I plan to decrease the total nitrogen ppm by fertilizing at only 1/2 the amounts I am using now.

CL

[Ray]

CL - the stuff I use and resell is the original formula, made by Greencare and sold to me by the Blackmore Co., who employs Bill Argo, one of the people who did the formulation work with folks at MSU. There are lots of knock-off out there, and they likely are just as good.

Concerning the "tweak" to the formula I mentioned earlier, he mentioned that it was added magnesium. Apparently, while most water supplies have adequate calcium and magnesium in them, south Florida is on a coral aquifer, so there is plenty of calcium, but no magnesium to speak of. Adding a teaspoon of Epsom Salts per gallon of fertilizer should remedy that.

Concerning Tucker's comment about not getting blooms, Bill said that while not absolute, more often than not, when folks start seeing nutritional issues, it is pH related. Tucker - which MSU formula were you using, and with what water supply?

[Cym Ladye]

Ray,

What are the numbers on the original MSU formula? I add oyster shell to my potting mix and epsom salts at a rate of 1 tsp/gal mixed with the fertilizer concentrate once a month (ie every other fertilizing).

I am beginning to believe that the "jungle syndrome" is simply due to over-fertilizing. i have seen excess nitrogen causing that in other fertilizing programs. Why not with the MSU formula? Just too much of a good thing?

CL

[tucker85]

Originally Posted by Ray

Apparently, while most water supplies have adequate calcium and magnesium in them, south Florida is on a coral aquifer, so there is plenty of calcium, but no magnesium to speak of. Adding a teaspoon of Epsom Salts per gallon of fertilizer should remedy that.

Concerning Tucker's comment about not getting blooms, Bill said that while not absolute, more often than not, when folks start seeing nutritional issues, it is pH related. Tucker - which MSU formula were you using, and with what water supply?

Ray, thank you for this very interesting information. I use the Ft. Lauderdale municipal water supply which has plenty of calcium and has a high pH (around pH 8). It's interesting that you mention the pH in relation to blooming because just about the time I switched from MSU to a balanced fertilizer I started adding a little vinegar to lower the pH. It might be the lower pH that contributed to the better blooming rather than the balanced fertilizer. I used several MSU type fertilizers but the one I used most was by Southern Ag. It sounds as though the MSU formula with added magnesium and a low pH might be the right combination.