Saw your post down close to the bottom of the page, so I thought I'd bump it up. I think your idea of curved beds is a good one. Use a water hose to make the shape, and then ride your lawnmower close by to make sure you can mow the curves (that they are not too sharp).

As far as edging, there are lot of options, depending on what you want to achieve. Bricks or stone laid so the lawnmower can mow the edge of the lawn without using a trimmer is a good choice. Or lots of stores have different edgings you can use, from steel edges to more decorative plastic ones. Each edging has its pros and cons, so you have to decide what the most important feature is for you.

As for your siding, I would be careful raising the beds because you don't want to encourage termites.

A width of about 3-4' sounds good to me. You can reach in there for weeding, but it's not too wide where you would need paths for weeding.

Good luck!

Curved lines tend to look more natural and are actually easier to mow, at least for me.

I would pull the bed away from the house and for the space between the bed and the house put down a heavy duty weed barrier cloth and cover it with decomposed granite or something similar. It looks like you don't have enough room to put a decent layer of mulch over the soil without the mulch coming into contact with the siding. Plus, most of the time, the eaves of the house will keep the rain from reaching anything planted against the house.

I'm not sure on the edging issue. I have yet to find something that keeps St. Augustine and Bermuda in place or allows the lawn mower to edge the grass. But, if you have a raised bed (I wouldn't make it very tall in front of the window), as long as it's a relatively hard surface that can tolerate the weed whacker, it's pretty easy to edge. Or, you can put a pathway next to the edge of the bed and periodically pull any stray grass.

Good luck and enjoy the new bed!

Thanks for the great ideas-I'm finally getting around tot his garden now that it has cooled off. I'll use a hose to lay it out.

I have some black edging I'll put it in to hold back the lawn (or attempt to). Can I also put in a trough with this edging? I like the idea of running a trough around the edge of the garden and mulching it or graveling it in. I'd like a nice distinct barrier without anything for my husband to gripe about mowing wise!