Been there, done that - the leveling part. You can either dig down on the high end until it is level with the low end and build a small retaining wall at the head of the bed. Then construct the bed in any fashion of the level portion. Use string for leveling as eyeball won't cut it. Or you can build up the low end of the bed. The problem with that approach is most cost - more wood or whatever materials you use to frame it in and MUCH more fill dirt. If the incline is not too severe you can run the bed parallel to the incline rather than perpendicular to it. Still has greater cost associated with it for material and soil to level it but it will give you better consistency for watering - less pooling and run off. A third alternative is to build terraced beds - stepped beds down the incline. At the top maybe only 12" wide, the next down 2' wide, 3' for the next etc. Makes access to them a bit more difficult but is attractive and needs less digging. Pics linked below. Dave Here is a link that might be useful: Terraced garden bed

My drip system parts are by raindrip inc. They have worked quite well. The timer is a Claber Video 2.

As to peas on a trellis, the peas will weave themselves through the terrace. So once you get a foot or so off the ground, both sides are being used, no matter where they're coming out of the ground. But sure. Plant on both sides if you want. Mulch has two benefits. One, it prevents soil splashing, but the other is that is reduces watering needs, which might splash that soil in the first place. And yes, I agree about not underplanting. That's not mulch, because it's using water and nutrients. I would stay away from large-chunk/chipped bark mulch, however. It doesn't degrade in a timely way, and by the end of the season, you probably won't be able to dig it in. Use mulch that is well shredded that will compose in situ in the course of the season.

I have seen stuff called "topsoil" that was spent foundry sand, sand with enough organic material added to make the light tan stuff black, stuff skimmed off a swamp, stuff that is not good soil. The definition of topsoil is, quite simply, the top 4 to 12 inches of soil, so yes the term is meaningless as the link I posted above will help those that have a hard time understanding what I write understand, if they read it. The term "garden soil" means about the same thing as "topsoil", nothing. Many people have posted here that what they got when they ordered is not what they expected and many people have made it clear they would not know good soil when they saw it. If someone giving advice here cannot define "topsoil" they should not be recommending to someone that that is what they need. I have asked you, tox, to define "topsoil" and so far you have not done so. kimmq is kimmsr