ljrd3, For the first year treat these as potted plants untill the roots grow into the surrounding soil. The water must go directly into the potting soil that came with the plant. Use 12th of a gallon per day if the temperature is in the 70"s. Use 1/6th of a gallon per day if the temperature is in the 80's. Use 1/4 of a gallon per day if the temperature is in the 90's. Delay one day for each 1/4 inch of natural rain. The second year use the same total amounts, however, you can begin to water less frequently using proportionally more each time and also watering a greater area around the plants.

Welcome to New England! The Maine gardening forum is often kind of slow, so if you don't get answers you are looking for you might try the New England forum which is fairly active. How large an area is this and how steep is the hill? Do you know the zone? Maine covers a lot of zones; you can use the map linked below to find your zone if you don't know. What is the pattern traffic like? Do you walk anywhere across a broad slope, or are you more likely to walk in a narrower band? How much sun is part shady? Is there enough sun to grow grass? Would you consider adding some shrubs to focus where folks walk and then adding some rustic steps or water bars to help divert the water? Is it possible to divert some of the water before it gets to the slope with a swale to reduce the flow down the slope? Here's a website from the Maine DEP that has a bunch of different suggestions for erosion control and plants for use with lakefront properties such as infiltration steps and water bars. http://www.maine.gov/dep/land/watershed/materials.html A photo or two that includes the area in question as well as what is above and on either side of the slope may help answer some of my questions. IME there aren't many ground covers that will take heavy foot traffic that will also tolerate part shade and high water flow, and if you walk here regularly, it may be difficult to get something established. There are shade grasses that might work, especially if you could keep folks from walking on one part of the area you are working to establish for a full growing season, so that one year you do one part, and the next year you do another part. We have a sedge that grows wild in areas of mostly shade to mostly sun, Carex pensylvanica. It will take occasional foot traffic when established, but not heavy foot traffic, so you would also need stepping stones. You would want to get flats of plants if you decide to go this route. I don't know if the place below sells to the public if buying in quantity, but I imagine that there are native plant nurseries that sell in quantity. http://www.northcreeknurseries.com/plantName/Carex-pensylvanica- Partridge berry AKA Mitchella repens is another native groundcover, but like the sedge wouldn't want regular traffic and would need stepping stones. Here is a link that might be useful: Maine plant hardiness map

If you live in the greater Seattle area or anywhere close to Puget Sound, you are zone 8. Zone 7 is not until you are up in the Cascade foothills. Woody groundcovers are the best for erosion control and these are never available by seed. A 75 degree slope is extremely steep and I would suggest using geotextiles to secure the slope before planting. Plants that could work for you are kinnikinnick (Arctostaphylos uva-ursi), bearberry (Cotoneaster dammeri), creeping raspberry (Rubus calycinoides), salal (Gaultheria shallon) and low Oregon grape (Mahonia repens). All will tolerate partial shade, all are evergreen and the kinnikinnick, salal and Oregon grape are native plants so minimal maintenance required once established. Another excellent plant for slope stabilization that is not a groundcover is our native western sword fern, Polystichum munitum.

I would advise you not to run downspouts underground. All you're doing is taking a concentrated flow of water and discharging it elsewhere. Not only do you risk trouble later (clogged underground pipe), the "elsewhere" would be near the bottom of a hill which in your case might be very close to a neighbor's yard. A universal regulation in communities is that you cannot discharge a concentrated flow of water into the neighbor's yard. If it ends up causing them problems, you would be responsible for rectifying the situation. If you get plants to cover the ground, instead of bare washed earth, then you will solve the problem. And the expense and work of burying a pipe underground does not alleviate the need to establish plants anyway. "Maybe I'll make one more attempt with the shade grass this fall." That is like suggesting that even though socialism has brought misery to people wherever on earth it has been tried, that we could rename it and try it again. Look again at how well the grass that used to be there is doing. I think all the pros here are telling you that grass is not going to work. Nor would it be pleasant to mow on the slope even if it did work. " I cannot use invasive groundcover." There are some people who would call nearly any groundcover invasive because it spreads laterally, which is the nature of the plants -- having the ability to cover the ground. This is usually a asset when getting groundcover established as it limits cost. But it usually means that where groundcover meets certain objects, it might need to be trimmed, or "barricaded," so as not to overrun them. A lawn must be trimmed and edged more or less weekly so as not to become a problem. A groundcover's height is automatically limited by genetics and usually only needs its edges trimmed. And usually, much less frequently than a grass lawn. Take a good look at the neighbor's yard. I would suggest that they are also in need of a groundcover. If you both had the same groundcover there would be no need to worry about it at the property line. I suggest you pick the right one and lead the way. Surely there are other shady, sloped areas in your town where people have ALREADY solved this problem. Take a look around and see what groundcover they used as it is probably the groundcover that will work best for you, too.