This information is very recent: http://www.nytimes.com/2010/05/06/opinion/06kristof.html Here is a link that might be useful: New York Times May 5, 2010 article

The death of the turf grass and take over by oxalis is nature's way of telling you turf grass just isn't likely going to grow there anymore. You could try to find a shade tolerant grass seed and see how it goes. I don't know of any turf grasses that thrive in the shade though, just some that are more tolerant than others. I think you have to make a choice at this point. Work with nature or against nature. Either is fine, but working against nature will always involve more money, time and labor than working with it. You might get grass to grow and suppress the oxalis, but only with a shade tolerant variety and if the roots of the tree extend into the area then with increased water and fertilization as well. A personal recommendation would be replanting the area with shade tolerant wild flowers adaptable to your cold hardiness zone. Get a mix with a lot of varieties because some likely won't be adaptable to the area. You can pretty much forget about killing the oxalis as it will readily regrow from it's underground parts where it stores energy. Even synthetic herbicides may be of limited use with it. You likely have to outcompete it by choosing plants adaptable to the current conditions that can shade it out by virtue of being taller.

Salt kills slugs, for sure, but northspruce is right that it's not good for the soil (or plants). I don't know why I didn't think to mention this before (probably because I'm still at the ammonia spray stage of warfare), but Lee Valley Tools sells a copper roll for slug control. It doesn't kill slugs, but it keeps them off your plants. Copper gives slugs an electric shock when they touch it. If you get the copper around your plants before the slugs get into the nooks and crannies of the leaf axils (early spring), then the plants are safe. (If you put it on after the slugs are on the plant, you just encourage them to stay! The roll is 5 inches wide, but I imagine you could cut that down. It's fairly pricey, but you wouldn't have to replace the copper wire each year. Although it would be a hastle to put the stuff around the whole garden, it could be useful for special plants, or for plants that are the most susceptible to slug damage. I've also heard that you can get rolls of copper sheeting from metal suppliers, and cut strips yourself. The copper kitchen scrub pads can also be unraveled and the strands placed around the plant. Heck, you could even surround your very special plants with pennies! I might try the Copper Blocker next year (too late this season...the slugs are already on the plants. Besides, my ammonia spray is ready to go!!) Here is a link that might be useful: Lee Valley's Copper Blocker

I use to have the same problem and then I found this info and remembered my GF used sugar to get rid of stickers Just do an organic program, and that will take care of the weeds. I started putting sugar on my lawn 8 or 9 years ago, and the weeds started dying out right away. Sugar doesn't kill the grass or anything else. What it does, is it nourishes the beneficial microbes that work round the clock enriching the lawn. Fertilizers and other chemical products you buy for the lawn, kill all these microbes, and the beneficial nematoses and insects that feed on harmful insects. Earthworms, tunnel through the soil and keep it aerated, and their droppings ( castings) add nutrients. Toads, lizards and other harmless critters that cannot live in your yard iif you are using chemicals,will not be able to feed on insects. I used to spray once a month for insects, and it kind of kept them off my roses etc. Since I stopped using chemicals, I have no insect problems. I have no weeds in my lawn, because weeds like poor soil, and will not live long in rich soil. If I were you, I would broadcast 4 pounds sugar per 1000 sq,ft, and water it in well. Don't worry about the weeds. The microbes should start reproducing and all of the family of them will work on your lawn all winter. Apply sugar again in the spring, and next fall. Watr well each time. Watering to a depth of at least 6 inches encourages a deep root system, and deep roots help protect against heat, cold and drought damage. I am in North Texas, and have had the same kind of dry weather you are having up there. I watered only once a week, and my lawn ios still nice and green.When the top 3 or 4 inches of the soil are dry, there is still moisture down where the roots are. I just broadcast my sugar by hand, like feeding chickens. Some other things you can broadcast around the yard,that will just add more nutrients are lava sand and alfalfa meal. You will probably have to get the alfalfa meal at a feed store. The poundage will be different, but you want about the same amount of coverage all over with these as you get with that 4 pounds per 1000 sq.ft of sugar. You can even mix them all together. Don't go by weight, go by volume, and use the 4 pounds per 100 sq.ft of sugar to measure the lava sand and alfalfa meal. Like, one gallon bucket of each. You can use both of them or either of them. Or just the sugar by itself will do a lot and you will be surprised at the results you get in your yard next year. If you can find Corn gluten meal, you could apply that at the rate of 15 to 20 pounds per 1000 sq,ft. It wil act as a deterent to the weed seeds germinating over the fall, and you should not get as many, if any, next spring. The organics would be an easier, more productive, and much cheaper way for you to go. I go with the sugar and let the microbes enrich the soil, and the rich soil getting rid of the weeds.