I have many questions pertaining to using vinegar as a herbicide.
... What strength gives good results against my weeds?
... Is it effective on a cloudy day, or does full sun give best results?
... What happens if it rains an hour, two hours, or 3 hours after it is sprayed?
... How heavily must it be sprayed?
... Will it noticeably change the soil?
... How close to a good plant can it be sprayed?
... If the rain washes the vinegar into the soil, will it damage the good plants?
... Do I need to add liquid soap as a sticker?
There's a few things that I was already aware of. 30% vinegar is strong enough to burn sensitive parts of my body. So care must be taken to avoid splashing it into eyes, mouth, etc. In the past I've worked with pickling vinegar (10%) and it burned the skin around my finger nails, so with this stronger stuff I plan to wear gloves. My tender spots apparently don't like vinegar.
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| Moss covered concrete walkway. |
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| After photo. |
It's been raining daily, so I waited for a day where there was a low chance of rain. I finally got one, yahoo!!!! Using a spritzing hand sprayer, I sprayed a few test areas. I sprayed to just wet the plants, but didn't over wet to the point that the vinegar ran into the soil.
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| Assorted weeds and grasses |
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| After photo. |
Within hours the sensitive plants started to either bleach out or wilt. Even the honohono grass wilted! By the next day I could easily see where I had sprayed and where I hadn't. By the third day, most of the weeds looked dead or dying, including the grasses.
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| Stone steps. Weeds growing in the crevasses. |
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| After photo. |
I'm impressed. So I answered my first question......30% gives good results. I also answer the "how heavily to spray" question....just wet the leaves. I sprayed weeds right up to good plants, protecting the good plant from the direct spray with a piece of cardboard. So far, I haven't seen any herbicide damage signs in the good plants.
On the third day it rained. So now I'll watch to see what happens when the rain washes the vinegar into the soil. We shall see if the soil pH changes or if the good plants start showing damage.
I didn't use soap. At 30% strength it doesn't seem to need it. But I'm going to try watering the vinegar down to 15% and see what happens. I may use soap in that solution.
I plan to try using it on a cloudy day to see if that makes a difference. And if it happens to rain on the day I spray, I'll keep records and see what effect that rain had.
Interesting. I remember trying store vinegar (5% I believe) a number of years ago and while it killed leaves, it didn't appear to kill the entire plant. Obviously, I was using the wrong strength! I'm curious about how the stronger vinegar will effect soil pH too.
ReplyDeleteDish soap. I always see it in recipes but other than acting as an emulsifier (which it doesn't seem you'd need for vinegar/H2O), do you know what its function is supposed to be? I'm not clear on that. It's basic, so it would offset the pH somewhat - maybe not enough to matter.
I'll let you know how this experiment progresses. I plan to check the soil pH after a couple light rains.
ReplyDeleteThe soap also acts as a spreader/sticker. Not as good as the commercial greenhouse stuff, but far cheaper and less polluting. Since one only uses a little bit in a gallon, I don't think that it would affect the pH much.
The only problem I see with this is that if you keep spraying long term you will destroy the beneficial organisms in the soil, and that imbalance will spread to areas you aren't spraying. If enough is used over time, It will reach your water table which is high where you live.
ReplyDeleteNot certain if you know this but white vinegar even Heinz is basically derived from chemicals. White vinegar comes from the residue of the distillation of drinking alcohol.
I myself, won't use it. There is the temptation.....even though I live in the desert, we have quack grass and it is very invasive and destructive. The only way I can control it, and you can only control it, not kill it, is to put 18" of straw in those areas. I can't imagine the situation you have.....living in a tropical area.
Eventually the problems with the quack grass were more than I wanted to deal with and I switched to growing almost everything hydroponically or in air prune pots. I found Mr. Kratky who hails from your Lovely island.....and I adopted his way of growing hydroponically. I've made modifications but it works for a lot of things I grow seasonally or in the greenhouses.
If you only spray the leaves, the runoff is less, but you aren't killing the roots, so it will just grow back. I think this is why black plastic mulch is so popular - LOL. Let me put my thinking cap on.
Good points! I don't intend to excessively spray, but it's a very good warning to other gardeners.
ReplyDeleteRegardless of how the vinegar is produced, it's still acetic acid. If I could figure out how to produce my own, I would.
Yes, vinegar doesn't kill the roots of tenacious plants. That's an important note. So far I've learned that certain plants die from just one spraying, while others do not. And the younger the weed is, the better the control. Grasses are the most difficult weed to kill with vinegar. I haven't tried spraying any bushes, just ground growing weeds.
Hydroponics.....I have certain things growing via non-circulating hydroponics. I need to post some information about that. It's a great way for me to produce certain veggies while protecting them from slugs.