Vinegar for potted gardenia?

Has anyone ever heard to water a potted indoor gardenia with vinegar once a month to help keep the soil acid? I was told that by a little old lady who swore her mother did it years ago and always had the most beautiful gardenias in bloom. She said she thought she watered with undiluted vinegar once a month! Could this be correct?

Yes! Generations ago, vinegar was used to acidify the soil of acid-loving houseplants. Do not, however, use the vinegar undiluted! The proper rate is 1/2 teaspoon white vinegar to one quart of warm water.

I sometimes use this vinegar solution for my window-grown Meyer Lemon and orange plants, instead of the more modern Miracid.

Kevin
www.agardenforthehouse.com

Amazing! I will do this tomorrow. I'm overwintering a gardenia standard in my sunroom. It's got buds, but is gradually losing leaves although the conditions are good and other plants are thriving. I really think it just needs a more acid condition since I had repotted it with ordinary potting soil in September.

Thanks for your advice!

Would live vinegar have any added benefit? I'm just wondering. I wonder too much, lol.

Hoosier - another trick with the gardenia is to cover it with a plastic bag. For this is a plant that likes an enormous amount of humidity. In a dry room it will drop its leaves.

3jsmom31: What in the world is live vinegar? I'm guessing it's vinegar that forms when unpasteurized apple cider ferments?

wintergardener: Humidity doesn't seem to be a problem, even though I'm sure the higher the better. I keep a humidifier going all winter and mist everything every day. Thanks for the reminder though.

Well, live vinegar is vinegar before they pasteurize it to kill the yeasts and bacteria that produce the acetic acid. I wondered if the bacteria and yeast in live vinegar would add any benefit to the plant and soil. And yes, vinegar that forms from juice or sugar water that sits for a period of time is a form of live vinegar. There are many things that will ferment to produce vinegar beyond apple juice.

I would think that almost any yeast and bacteria would be beneficial to the soil, especially in something so elemental as vinegar. Great idea.

That's what I thought. It's sort of neat when you find real vinegar with the mother (a film that covers and protects the vinegar). It's another thing to grow, really.

The value of vinegar as it relates to indoor container culture is, or pretty much should be, limited to its use as an agent to neutralize your irrigation water's alkalinity, which is an issue separate from pH. White vinegar works perfectly fine. If you have access to pH paper or a reliable pH meter, add enough vinegar to a gallon of irrigation water to bring the pH down to 6.0., and note how much it took, so you can repeat as needed. Water with a pH of 6.0 will halt the normal upward creep of pH as your medium ages and help to eliminate pH induced micro-nutrient deficiencies. Fe and Mn are most commonly deficient because if pH issues.

Also, if you are using a soluble fertilizer (like MG), it almost surely contains Fe and Mn, so it's extremely unlikely you would have a deficiency of these nutrients because of an actual lack of the elements in the soil. Most of the micro-nutrients are forming insoluble compounds at pH levels much above 6.5, so if you even suspect an Fe or other micro-nutrient deficiency, often simply neutralizing the irrigation water's alkalinity and supplying it at a pH of 6.0 is enough to correct it.

If you feel your plant is suffering from a media with high pH, you can add 1-2 tablespoons of white vinegar to each gallon of irrigation water and apply it each time you water. That is usually enough to correct. If it does not correct, you have other (probably nutritional) issues.

Al

So there isn't any value in the beneficial bacteria in unpasteurized vinegar? I know that white vinegar works fine, just like a vitamin c tablet works fine, but an orange tastes better :).

I use only rainwater for watering my indoor plants. I rotate fertilizers and have used Miracid on the gardenia. Previously, I had this gardenia overwintered with no problem, good blooms and little loss of leaves. Possibly the problem started with repotting in normal potting soil, not an acid mix which the original medium most likely was. If I can get it through the winter, I'll repot in the spring. Thanks.

Sorry, didn't mean to distract from your original post. I am learning, too. I have only one small gardenia so am curious about giving it the best care.

I doubt there is any measurable or practical value to be derived from the use of vinegar in container culture, other than as an agent to reduce the pH of irrigation water or to help neutralize it's alkalinity. It's just something usually found in the home that happens to be a suitable substitute for other more commonly used acids used in commercial growing to reduce pH and neutralize alkalinity.

Keep in mind that while it helps to use media with pH in the favorable range, it's no where near as important as it is in mineral soils with much greater bulk density (garden soil) and a high buffering capacity. In container culture, it is the pH of the soil solution that is most important.

Al

Why couldn't you use coffee grounds to add acid to the soil? I thought Vinegar could kill plants. Iwould almost be afraid to use vinegar, but coffee I have used. Just plain cool coffee, so as not to burn the plant.

Used coffee grounds are not acidic, or if they are, they're just barely so. Vinegar, like any acid will kill plants at high concentrations, but like other commonly used acids (sulfuric, phosphoric, nitric .....) in various forms of plant culture, it can be effective at lowering pH and neutralizing alkalinity. The weed killer "Weed-B-Gone" is simply a high concentration of synthetic auxin, the same active ingredient in rooting aids - but also in the infamous agent orange, so you can see that 'concentration' levels are key.

The topic of adding dilute coffee/tea to plants as a "tonic" comes up frequently. I replied on one thread & got beat up pretty bad for offering the reply, but Arabica (coffee) and Camellia (tea) are known for their toxic alkaloid (caffeine) content and their allelopathic affect on plants as well as autotoxic ( poison to their own seedlings) effects on future generations. Caffeine interferes with root development by impairing protein metabolism. This affects activity of an important bio-compound (PPO) and lignification (the process of becoming woody), crucial steps for root formation.

We also know that the tannins in both coffee and tea are known allelopaths (growth inhibitors). There are ongoing experiments to develop herbicides using extracts from both coffee and tea that cause me to want to say they might serve better as a nonselective herbicide than as a tonic. I would not use either on my plants.

Al

I am not going to beat you up, too weak...☺ I'm a wimp. But I will not use any more coffee to water plants, I guess.
I learn a lot of things from DG folks and I appreciate it very much.
Just have to learn how to re-think in my old age. Just use in moderation, huh? Thanks
Charleen