Salt the cheap stuff from a feed store will help suppress weeds also vinegar and that flame torch idea would pronely be a good one when fire conditions allow
If nothing else concentrate on the patio and mow or get someone to grade the driveway Also if you do get the driveway deweeded it helps to drive in a different spot so you run over all the weeds when you come home

Two options are horticultural vinegar and a weed torch. Horticultural vinegar is much stronger than store vinegar and is fairly dangerous to handle so it requires lots of care. (More so than Round-Up.) Horticultural vinegar is not approved for use as a weed killer in all states and very little is known about the environmental effect of its use in large quantities. I don't use it in because my land slopes into a stream and that stream does not need to be acidified.

A weed torch does have it's obvious dangers but overall is probably the safer route. It's hard to say which would be more environmentally friendly... a weed torch uses fossil fuels.

Long term for the patio, you could pull up the bricks and reset them using one of the new polymerized sand beds. After you set everything, you water it and it turns solid. Weeds could probably get through it eventually, but it'd be a long while. This is hardly a cheap option, though!

I've used boiling water in a very small application, with good results.Not practical for larger areas. I wonder if one of those steam-cleaning units advertised on TV would be effective? Can such units be rented?

Boiling water works really well. A weed torch is good but we accidentally set fire to our mulch last time we tried it. The dry lavender stalks adjacent to the garden path smelled wonderful burning, but we haven't tried that method since.

I have been putting down sections of corrugated tin roofing on areas that have gotten away from me. It kills the weeds and after a couple of weeks or so I can move it to another area. Black plastic mulch would do the same but you'd have to stake it so it didn't blow away.

I like the steam cleaner idea and I already have one. But the length of the extension cord could be a problem.

This is the perfect situation for a weed torch! They operate off a small propane tank and are very easy (and fun) to use.

where it hits soil directly, or the hardscape, it stays poison and ends up getting into the water and mutating tadpoles and stuff

Actually, when it hits the soil, either directly or washed off pavement, the microbes break it down quickly into glucose and CO2.

Salt would be far worse than glyphosate.

A weed torch would work, but it doesn't kill the roots like glyphosate. Maybe one round of glyphosate for a mass killing and then use the torch for control?

Y'know, when people post at an organic forum that they don't want to use round-up, suggesting round-up to them might not be the best advice. I'd agree boiling water or torch if she can use either safely w/o burning herself; then 10% or stronger vinegar to keep the weeds down.

Thanks everybody for the responses! I'm going to go for a torch. If anyone has recommendations for a relatively inexpensive, effective one, please let me know.

The torch, boiling water, and vinegar will work short term. all of those will kill the top growth but not the roots. Salt will kill the plant roots.
Long term "weed" control in the brick patio means pulling those pavers up, eliminating any "weeds" then found and relaying the patio with new sand in the joints. Gravel can be raked hard enough to disturb the plant roots so the "weeds" die. Somewhat difficult unless a landscape rake pulled behind a tractor is used. That can also help relevel that driveway.
Vinegar is much less of an environmental problem then any glyphosate product ever was. "Weeds" are developing immunities to the glyphosates because of gross over use.

I guess that whether or not the roots of a given weed will be killed by surface methods...depends on the size of the weed, how vigorous/deep the roots are, and how often a person repeats the surface treatment.

My boiling water 'treatment' of weeds growing between my pavers next to my short driveway, only took one application. Seedlings show up each spring, but that's to be expected.

I'm wondering if the steam treatment, if held over the larger weeds for a length of time, would 'cook' the roots and actually kill the entire plant? Or follow up treatment of any plants that didn't DIE, DIE, DIE, YOU WICKED WEED with the first steam treatment. I would be inclined to test this method out before resorting to salt or even the less invasive method of dragging the driveway.

Repeated treatments with the weed torch will kill a weed. Period. A plant cannot survive if the food and energy making organs (leaves) keep being fried.

Annual weeds are likely to be killed outright with the first zap. The perennial ones may take a couple or three treatments if they keep returning.

Thanks, all. I'm really going to try to talk her into buying a torch. If she goes for it, I'll let you know how it goes for us.

RK

Keep in mind that any type of thermal weeder uses a non renewable energy source to produce that heat. The initial investment in equipment can be expensive and the ongoing cost will be expensive.