Sodium chlorate is a cheap and nasty weedkiller that CAN leave you ground impotent for years.
It's a residual weedkiller and I can't for the life of me understand why it hasn't been banned to be honest! It forms a gaseous layer in the soil killing any plantlife as it germinates.
Only to be used on gravel paths I would think as it has a tendency to 'creep'!

I don't like using any weedkillers myself, but if I was to use them I would use something that was glphosate based. Glphosate is a systemic weedkiller which once absorbed by the plant travels through it's system killing it. It supposedly becomes inert on contact with the soil and has no effect on future plant germination/growth.

For mares taill, the foliage is best scuffed before application to break the water repellant coating.

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My Majesty made for him a garden anew in order
to present to him vegetables and all beautiful flowers.- Offerings of Thutmose III to Amon-Ra (1500 BCE)