I've tried the heavy black plastic for weeds, and it takes about a year. The plastic broke in one or two spots, and weeds poking right through. Those plants of which you speak will probably survive that treatment. They say the black plastic is not good for the soil. I'm using Roundup on a couple of ditch lilies, and I'm guessing it will take more than one application they are that tough, may lurk for years and pop back up. In the meantime, I'm deadheading so they don't produce seed as I was finding seedlings all over and yanked those. Roundup should be safe enough if applied according to directions. Once it hits the ground, it apparently doesn't leave a residue or leach into the soil. It travels through the leaves down to the roots. Those things are so persistent, I think they will pop back up at some point no matter what I do. Digging those tough things is not an option although my neighbors got rid of a few clumps doing that, left a couple other ones to grow.

Thanks for the reply, kato! Your questions are so helpful in making me think more about this. We do have a mower but the lawn is so small it takes more time to haul it out of the basement and plug it in than to mow, so we'd like eliminate the need to mow completely. Our neighbors use the mowing method and their lawn looks tidy for, oh, about a week before it needs to be mowed again. My ideal is something that needs tending in the spring and the fall and can be simply enjoyed the rest of the year. I'm an innocent when it comes to herbicides; I had assumed they were off the table for the lawn-killing project because 5 other yards touch ours and (I assume) you can't control runoff and I don't want to piss off the neighbors. Also, we have lots of snakes living in the yard, neighborhood cats hanging out, and little kids playing back there. All this made me think a non-chemical method was best, even if it was more labor-intensive. But I don't know... As for replacing the spearmint, I need something that can be swept or raked--the two neighbors kitty-corner on either side have huge oaks that fill our yard with leaves. I am, however, planning a pea gravel "pit" on one side of the yard to replace our sandbox. I was also worried about kids going splat on hard stone (my kids are currently 2.5 and 5.5), but stone just seems like a better choice in the long run. I'm pretty sure I could get salvage broken concrete slabs instead of flagstone to keep costs down, if need be. On the other hand, if we go the groundcover route my initial thoughts were creeping thyme or chamomile. But I'm worried I can't keep my kids out of the yard long enough for the groundcover to establish itself. I should also say that all the borders of the yard are going to be devoted to fruit cultivation--we already have a serviceberry, blueberry, quince, gooseberry, rhubarb patch, and huge raspberry patch, and are planning on adding blackberries and a fig tree, so the actual area of "lawn-like" area is smaller than 20 x 30.

Thanks for all of the suggestions about removing the mold, and particularly the messages about finding and fixing the source. Here is an update... When I went to remove the mold wearing all sorts of protective gear and armed with lots of supplies (toxic and non), I realized that the wetness emanated from behind the studs which covered the corner AND that there was a lot of dampness hidden in the corner. You can predict the rest of the story... The studs came out when the contractor arrived and so much more mold and rotten wood was exposed. Clearly, there was a baaaad leak on the exterior wall that had been leaking for a long time and had rotted out the wood in the sill and plate. Forget wiping off the mold, it was time to fix the leak and remove all of the soggy rotten moldy wood. The tar paper between the layers of stucco and wood framing had disintegrated in the wet areas. After two weeks, lots of stucco crack sealing, some new flashing, rain and hose spraying, there are no more leaks in this area. The wet wood is gone. We will wait to close up the area until we are sure that there are no more leaks. Thanks again for the suggestions and moral support!

I'm in north Alabama (where healthy crabgrass will take over pets, small children, and low flying planes). At the moment, I'm waiting on the soil temperature to come up closer to 50 degrees, so as to apply Scotts® Halts Crabgrass & Grassy Weed Preventer at the opportune time. I completely agree with your statement about growing a healthy lawn, which is why I'm taking steps to prevent the crabgrass and eliminate existing weeds. Since I'm on step 1 (application of crabgrass preventer), I don't have the soil pH info, nor the organic matter content (yet). Drainage is fine. That being the case, what would be the best approach to eliminating existing chickweed? I really haven't had much luck with big box herbicides. I haven't tried the Bayer brand, though the ones I've tried seem to hurt the weed's feelings for a few days and that's about it.