I looked into the wood chip idea I just got a fresh truckload of them for Spring. A few things you can expect: The chips are rougher and coarser than store bought. If this bothers you, you can throw down a thick layer of the cheap stuff and then a thin coat of expensive ones on top. they come in various colors. After a while if you dig around in it you may see white/ off white threads running around in it, or worms crawling around down there, or even mushrooms on top of it. These are decomposers. They are busy changing it from wood chips into plant food. They won't bother you or your plants, they only like dead things. The chips start off a brightish white and fade slowly through grey and get soft and blackish as they meld into the soil. The only concern I have with wood chips is the runoff where the next grand canyon is forming -- it is a veritable river when it gets flowing A valid concern. Can you run a heap of rocks down the canyon for the water to flow through without moving them? Maybe have a series of lashed stick dams to let water through but hold the chips? Lay branches across it? I read that with chips you normally put down 4-6 inches of it on bare dirt. Would that be enough to prevent rushing water from carrying it away? I'm not sure. Or would I be better off building a temporary drainage system to route the water under the tree bed until the plants can grow outward and hold the soil together? Maybe lay a perforated pipe on top of the ground, bury it in chips? I guess I wrongfully assumed that I would need to plant the pachysandra all over the area, but your suggestion about letting it grow outward over several years sounds much more logical. There are various ways to handle this. The rings were meant to give you something decorative, something orderly to look at while it's developing. You could plant them in a loose even scatter across the whole bed. This won't look like much at first but might be faster. You could buy and install more plants whenever it's convenient (you just move the chips out of the way and plant) You could subdivide and move the existing plants every few years. You could plant once and let them do their thing. They'll all work. Looking at the the second picture I see I misjudged something. I had thought the trees were centered in the bed. They're not, they're along one edge. This means a ring around each tree won't be starting them in the middle, it'll be starting along one side. This is not a deal breaker. You could do rings around the trees and start some sprinkled along the left side of that second picture so it keeps up with the tree side. Patience will be key. The rule of thump with Pachysandra is: The first year it sleeps. The second year it creeps. The third year it leaps. Thank you again for your reply. You've definitely given me a silver lining on what I thought would be a daunting and expensive project! I love it when this Internet stuff works. 8-)

If I didn't have quackgrass, gardening would be a total joy. I've been battling it and learning about it for the last 6 years, losing nearly every battle. Like you, I have eliminated Quackgrass from the middle of one of my gardens. When it comes up somewhere, and it does, I dig up the area, other plants and all, and get as much of the root out of there as I can. Then I monitor it and keep getting it out. In this garden, it's definitely do-able because it's not totally infested everywhere. To keep it from entering my garden, I avoided planting any of my perennials within about 14" of the garden's edge...because most of the quackgrass enters from my quack-infested lawn. In that 14" strip between my garden and the lawn, I put down a thick cloth barrier and then covered it up with the same mulch that covers my garden, so it looks like part of my garden and creates a neat "edge", albeit a bit one. Now, I pretty much just have to "guard the border". I have found that the darn quackgrass comes up right through the cloth, so eventually, I will replace it with 6 mil black plastic. However, this border patrol area gives me TIME to catch the invader before it gets to my precious plants. Because to me, the biggest, ugliest job is when I have to lift up plants and totally strip them bare of soil to get rid of the quackgrass roots that are mingling. In another garden, I have so much quackgrass right now, I'm digging out everything that I want to keep and will be rounding up. THen, nothing will go back into the garden until its roots have been cleaned out. It's a huge job. When I'm finished, I think I am going to change this garden to an annual one, as the quackgrass seems to continually cause me big problems there. If I make it a garden for annuals, I can round up the garden each year in the spring if I have to. Then plant a few weeks later. I hate quackgrass. I hope perhaps some idea here is helpful. I am learning to accept this weed and I do get satisfaction when I dig it out!

While a natural vegetation is always best for steep slopes, have you considered a mulch mat? There is a nonwoven mat made from industrial hemp that is all natural, easy to install, and nice looking. Because it's a mat that is anchored down, it won't slide down the hill. It'll slowly biodegrade over time. Combining it with some plantings would be a cost effective solution; over time, as the mats degrade, the vegetation can take over. Like any mulch product, though, you have to like the looks of it. Here's the website: www.woven-earth.com. Outside of the mulch, I'd agree with morpheuspa that a wildflower mix would walk the lines between aesthetics, effectiveness, and labor.

Horehound is in the mint family. It grows much like the horrible Bindweed aka, Morning Glory. Very aggressive roots make their way across large areas in just one season. My neighbor accidentally introduced mint to the neighborhood decades ago. I fought it by digging and pulling and pulling and chopping for years, and though it cleaned up the beds appearance, disturbing those roots that way was the worst thing I could have done, it encouraged more mint. Your horehound grows the same way. I resorted to Roundup. Really soaking it and doing it every 14 days. Don't pull them after a few days. Let the weed get good and dead. I sympathise and wish you luck. Here is a link:http://www.gardeningknowhow.com/edible/herbs/mint/invasive-mint-how-to-kill-mint-plants.htm