Orchid fertilizer/supplements question

[sewagner86]

I am currently using FeedMe! MSU orchid fertilizer from repotme. I also mix in a tiny bit of iron and superthrive and make it a weak fertilizer mixing. I water with this for 2 waterings (typically once a week) and then off for one. I also give this to my little violets.....they seem much much happier!

I have seen a foliar spray called MegaThrive advertised. I was wondering if it might be worth trying. I was curious if anyone has tried it?

My other question is, is there anything else I can give my plants or modifications to what I am doing now??

Thanks!!

[Dimples]

I don't use any of the products you mentioned but have seen a lot of threads where people have had malformed flowers caused by regular use of superthrive or other hormones/growth stimulant products. I think most people suggest those should be used once a month at most to avoid any undesirable side effects.

[Roberta]

First, Superthrive... you may want to go easy on that one. I had an episode where I was using it regularly, and started getting some distorted flowers (segments not separating properly) especially on some Cattleyas. A little research indicated that Superthrive WAS suspected of causing mutations. I stopped using it and haven't had that problem since. There have been some discussions in other threads about foliar feeding. While it may have some application in some controlled commercial environments, I would consider it a waste of time and money, (If someone claims that it works, can they guarantee that it doesn't wash into the medium???) The primary channel for absorbing water and fertilizer is through the roots... remember too that orchids (with a few exceptions) are light feeders since they grow slowly. Think of fertilizer as "vitamins" not "food" - green plants make their own food by photosyntheses, they need the minerals from fertilizer to build new tissue. Since they don't do that very fast, they don't utilize much. Concentrate on the other cultural factors, fertilizer is the least important one. And one of the most important factors is patience - orchids don't do anything fast so any changes that you make likely won't show an effect for several months. You need to observe... you can learn a lot that way in terms of what to modify, if anything, (Bill Thoms, a superb grower of Bulbophyllums and also winner of many cultural awards, talks of Power Of Observation... POO - above all, use your POO )

[estación seca]

Depending on what water you use you might not be giving enough calcium and magnesium. It's not possible to mix much of these into other fertilizers because things precipitate out, so they generally are dosed from a different product than the fertilizer.

Check your tap water quality report. If your total dissolved solids or hardness are low, use a cal/mag supplement. If you have plenty of calcium in your tap water you could mix that with more pure water so some calcium remains available.

If you're using very pure water, like rain or reverse osmosis, you will definitely need to use a cal/mag supplement.

Epsom salts are a source of magnesium, but not calcium. You can add a teaspoon of epsom salts to a gallon of water to supplement magnesium.

[Roberta]

Does the MSU fertilizer have calcium and magnesium? The pure-water type typically has it. If you're using the well-water version than it likely doesn't. I use MSU Cal-Mag with RO water, have had no indication of deficiencies on any plants - some of which get RO routinely, the rest get city water that has plenty of calcium (the bit of extra that comes with the fertilizer solution that I use makes no difference on those)

At any rate, whatever you're using, read the label, then you'll know what you are supplying (or not)

[estación seca]

I wonder whether the calcium and magnesium amounts in MSU blends are enough for non-cloud-forest plants. I suspect they put as much as possible into the mixture without having precipitation issues.

[Roberta]

I give everybody the same... My RO area includes both cloud-forest plants and others that are in the same location for other reasons (light, good area to hang, watering frequency, etc.) and I haven't seen any problems. And have been doing it for 3 or 4 years so there would have been plenty of time for problems to show up if there were any. Maybe there's enough dust to supply minerals??? Certainly not a sterile environment.

[sewagner86]

I am attaching a photo of the label of what exactly the label says.

Can I get a water report from the city? I have city water

[Roberta]

The formula does include calcium and magnesium. You should also be able to get a water report from the city. It likely is on their website. I don't see anything that might cause deficiency. So a normal fertilizer regimen - the "once weekly, weakly" should do fine for you. 1/2 teaspoon per gallon should work fine for just about everything. I add a top-dressing of time-release fertilizer in the spring for Cymbidiums, and for Catasetinae once they start growing fast because both benefit from the extra boost. But for everything else, the regular weak fertilizer works fine.

[sewagner86]

A report I found for the water here says it's 86 ppm for Calcium