Good weed killer?
Probably an old question but we have some very large areas that are covered with either rock, mulch or bricks and the weeds simply can't be kept up with, we've tried round up pro, ortho and a few others from the stores but they didn't work very well. Has anyone found anything that really worked?
Boiling water? Horticultural strength (20%) vinegar? Or...truly wicked...boiling vinegar! 
I've used boiling water on dandelions, kikuyu grass, mallow, Yellow Star Thistle growing in cracks on my sidewalk and in the street gutter (where the curb meets the street--that 90-degree spot).
It did a great job: killed the plants. I applied the water and maybe a day or two afterwards, I just used my weed stick (aka asparagus knife) and removed them.
Cynthia H.
Sunset Zone 17, USDA Zone 9
I've used boiling water on dandelions, kikuyu grass, mallow, Yellow Star Thistle growing in cracks on my sidewalk and in the street gutter (where the curb meets the street--that 90-degree spot).
It did a great job: killed the plants. I applied the water and maybe a day or two afterwards, I just used my weed stick (aka asparagus knife) and removed them.
Cynthia H.
Sunset Zone 17, USDA Zone 9
Poor poor little weeds 
NO PITY to them... I'll give it a shot, thanks!
-
Gary350
- Super Green Thumb
- Posts: 7419
- Joined: Mon Mar 23, 2009 1:59 pm
- Location: TN. 50 years of gardening experience.
Sodium Chlorate will do the job. This is something the old times use to use. The chemical companies wants everyone to forget this stuff exists so you will buy the new more expensive stuff that is dangerious and causes cancer. You can buy it for $2.00 a pound at any chemical company listed in the phone book yellow pages. It comes in 50 lb drums and 55 gallon drums. Mix about 1 lb in 20 gallons of water. It will kill anything and everything. It is not selective.
https://www.amazon.co.uk/Doff-Sodium-Chlorate-Weedkiller-500G/dp/B000TAN7FG
https://www.amazon.co.uk/Doff-Sodium-Chlorate-Weedkiller-500G/dp/B000TAN7FG
-
rainbowgardener
- Super Green Thumb
- Posts: 25279
- Joined: Sun Feb 15, 2009 6:04 pm
- Location: TN/GA 7b
Sodium chlorate NaClO3 is an oxygenated form of common salt, sodium chloride NaCl. Like common salt it is a soil sterilant, will sterilize the soil so that nothing will grow there, for a long time, as it is persistent in the soil. If sterilizing the soil is what you want to do, common salt works too.
Otherwise perhaps you could just lay weed barrier cloth under your rocks/ mulch? You can also temporarily kill all the weeds and weed seeds in the soil, by covering the area with clear plastic. Bury the edges so the plastic is tight against the soil and leave it for a few hot sunny weeks. Called solarizing, it will heat up the soil enough to kill everything, but doesn't sterilize the soil for the future.
Alternatively you could consider planting some of the areas in some kind of easy care groundcover.
Otherwise perhaps you could just lay weed barrier cloth under your rocks/ mulch? You can also temporarily kill all the weeds and weed seeds in the soil, by covering the area with clear plastic. Bury the edges so the plastic is tight against the soil and leave it for a few hot sunny weeks. Called solarizing, it will heat up the soil enough to kill everything, but doesn't sterilize the soil for the future.
Alternatively you could consider planting some of the areas in some kind of easy care groundcover.
I have some crab grass that is covering a large part of my ditch and I want it gone so will the boiling water and vinegar mix kill the junk grass but also not kill the soil for replanting? I would think that the vinegar would be very acidic to the soil, maybe add some lime after we dig up the junk grass?
I'd try boiling water alone at first. Remember to wait a day or so after application so it can do its work on the roots.
Then dig out the crab grass. If there are stubborn patches, more boiling water.
If there are *still* stubborn patches, vinegar time! Mine was used in a spot-application manner, not a widespread area. Due to possible consequences of boiling water, etc., to subsurface life forms (worms, beneficial soil fungi, etc.), maybe solarizing would be better for such a large area?
Worth a shot!
Cynthia
Then dig out the crab grass. If there are stubborn patches, more boiling water.
If there are *still* stubborn patches, vinegar time! Mine was used in a spot-application manner, not a widespread area. Due to possible consequences of boiling water, etc., to subsurface life forms (worms, beneficial soil fungi, etc.), maybe solarizing would be better for such a large area?
Worth a shot!
Cynthia
I pulled crabgrass until I had blisters on my fingers last night and I will try boiling some water tonight. I will also pick up some plastic this week and try sun light cooking. This will take about a 12pack of beer, I will let you guys know how things turn out. I will also try to post some pictures.