We have ground ivy (creeping charlie) that is trying to take over our back yard. We are against using pesticides, as we have a young son. Are there natural/organic ways of beating it (other than just painstakingly pulling it all out)?
You need to keep your grass healthy to help combat ground ivy. Water deeply and infrequently and fertilize properly. Have a soil test done at your local cooperative extension to see if there are any issues you need to correct and how much fertilizer you need to add. Ground ivy thrives in damp and insufficiently fertilized soils.
There have been university studies done on using Borax to kill ground ivy with some positive results but some tests didn't show any improvement.
On my blog, I show how the best way I found to remove ground ivy is with a thatch rake. In the fall I use a manual thatch rake to dethatch my lawn. If necessary I follow up by overseeding with a good grass seed and spreading about 1/3" layer of compost on top then water as directed for the seed. The way ground ivy grows and roots makes this very effective. It pulls up some other weeds too but not your grass as long as it's healthy. First time I tried it I was in shock how well it worked.
I've effectively killed it with a 20% horticultural vinegar using a pump sprayer. The grass around it will look like it died but actually goes dormant like it does in a drought. If you water it the day after you spray the vinegar, it will turn green. With the ground ivy, you have to be vigilant because if you leave one runner...the problem comes back. A week after a spray, I'll look for more and do it again. Also, look to see from where it's coming. If your neighbors have it and don't do anything about it, the problem will be endless. I recommend attacking the problem together if possible. Raising the pH with lime, spraying with a bacterial based compost tea and adding calcium and magnesium will help. Sweetening your soil will also help keep out dandelions.
You could just hire someone else to painstakingly pull it all out, like maybe a neighborhood kid in need of odd jobs. That might be cheaper and less effort than finding the perfect way to kill it. Plus, being social and offering jobs can be a good thing.
Remember, a tool to help pull weeds goes a long way, even if it is just a regular knife. With a tool, the plant doesn't break off at the roots, generally. Just stick it in the ground by the roots and pull back to loosen them; then pull it up. Granted, I haven't tried using a tool with creeping charlie (we don't have that around here, although we have something that looks exactly like it), but it worked great for our weeds this summer (I think we mostly had bind weed or something similar). Anyway, tools make weed pulling more enjoyable for me. Too bad I didn't know about that trick as a child. We had monster weeds, then, and grasshoppers to match.
I agree with the above comment about the structure of your lawn - I live in New Hampshire and typically have acidic soil - creeping Charlie likes damp acidic soil - typically in mulched areas, and it spreads to the lawn area. I've been putting down heavy amounts of lime to raise the alkaline level, but will try thatching this fall and borax in the spring!! (it takes a bit if time for the lime to break down into the soil).