baking soda on orchids?

[Joseph Siddron]

Ray..good morning...I googled using baking soda and the search said it lowers the pH..
Joe

---------- Post added at 08:46 AM ---------- Previous post was at 08:38 AM ----------

Baking soda can be used on the leaves for powder mildew, but not good for roots.. hydrogen peroxide will help roots when repotting to kill fungi

[Ray]

Originally Posted by Joseph Siddron

Ray..good morning...I googled using baking soda and the search said it lowers the pH..

I'd be very curious to see that reference.

[Joseph Siddron]

Google baking soda for Orchids

[SouthPark]

Originally Posted by Joseph Siddron

Google baking soda for Orchids

Joseph..... baking soda is alkaline. So adding it to a neutral pH solution would make the pH number go upward.

[Roberta]

Along with raising the pH to a level higher than orchids want (whatever someone says on the 'net, the laws of chemistry haven't been repealed... salts with strong base + weak acid = alkaline) , baking soda also contains sodium - which is bad news for essentially all plants except for those that grow very near the ocean, not just orchids.

[Ldrhawke]

I use rain water collected off the roof to water my orchids. The problem I found out the hard way is in Florida that also means it is loaded with black mildew spores. That combines with the water acidity of both the rain water and drinking water being below 6 it wasn’t long before the growing media looked like it was covered with lamp black from the black mildew outbreak. Black mildew needs a low pH to grow. I mixed a table spoon of baking soda(sodium bicarbonate with a gallon of water, pH about 8, and flushed the media with it. Two days later I flushed again....the run off water was solid black. I did this for a week. It did a great job of removing the black mold. No ill effects to the orchids. I keep my water pH just under 7 now by adding small amounts of Baking Soda and potassium biocarbonate, or dolomite to keep black mold in check.

I know orchids love acidity but so does black mold. Kicking the pH up a little hasn’t appeared to bother the orchids, but it destroys the black mold.

[Roberta]

It looks to me like you solved a nasty problem! The small amount of sodium doesn't look like an issue (and potassium would be even better) The "pure" water is almost battery acid!

[Ray]

1) I’d add Physan to the water to kill microbes before I’d ever add baking soda. Even bleach, which also contributes sodium (at a much lower concentration) would be better.

2) I know it was hyperbole, but pure water is nothing like battery acid. Pure water has a pH of 7 - totally neutral. It does, however, absorb air and the carbon dioxide in the air reacts and forms carbonic acid. The equilibrium pH of that solution is 5.4, but carbonic acid is such a weak acid that it’s completely overwhelmed by the addition of almost anything to the water.

Your glass of orange juice is probably in then 3.5-4 range, and much more stable.

[Ldrhawke]

Ray thanks for the input, but I am Microfeeding my orchids and do not use any chemicals that will destroy the microbe population. My little backyard orchid tree, uses a new and unique method of Microfeeding Biofertilizer (a dense bacteria culture);and not using any man made chemicals, and may hopefully be a first step in demonstrating this hypothesis and it’s benefits. I have started another thread on the topic of Microfeeding.

[Ray]

Well...baking soda is known to be a bactericide...