I plant hunks, am not that careful about such things. Plunk and run. If stems are crooked when planted they should reach for the sun, i.e. skyward, as they grow. Depth? I guess I press in the edges of the hunk to settle, the center is just watered in. Seems to work OK for me. The only separate flowers I plant are things like zinnias or nasties. I try to seat them about at the level they were in the jug, maybe a fraction deeper. Karen

peat pots aren't a great idea... they work ok for small seedlings, but i've found them 1) expensive 2) they tend to wick the moisture away from the plant. you'd be better off with shallow pots, buckets... i use window boxes to house my seedlings. the long, narrow, and shallow nature of the boxes is perfect, tho you need to be sure to water frequently and, every once and a while, drench the soil heavily to remove salts. use a really loose mix--half perlite, half potting soil or the like. lettuce thrives in those conditions if fertilized regularly and in small amounts. you can transplant it out into the garden, tho you might find (like me) that a couple window boxes with cut and come again lettuce produces enough salad to keep everyone happy. try these lettuces (from seeds) when things cool down: red sails, jericho, appollo arugula. all of them are very heat tolerant and prolific.

For the corn- it is probably not warm enough for them- in your house or outdoors just yet.They also like hot feet and sunny bodies- so probably not bright enough either- both of those factors can stress a plant/seedling- and compounding it with damp- on an already stressed system seems to bring discouraging results. I have made these observations with many of the seedlings I have started indoors- it does seem if I can get them warm enough- the other two factors don't matter as much- the same goes with if I can get them bright enough. I usually start sweet corn in the garden bed when the soil is warmer- but I do start ornamentals such as the variegated japanese and the indian corn indoors to have them ready to sell to others to grow on- Maybe if you put them out on bright sunny days and brought them in in the evening- or protected them some how in the evenings they might improve-

From my experience, the typical plywood sheeting panels rot in 3 months unless treated. I just don't see it as a good idea. What I would if in your case is to use a sheet of treated wood, then place a heavy duty tarp over to protect it from the soil, this will eliminate your concern with toxin leaching (unless you're concerned with using plastic as well). You want to have some concrete block in the middle to support the weight of all the soil unless you're gonna fill the bottom with sand or something. If you are going to fill the bottom, make sure there are no gaps or somehow promotes ants nesting, which will be a big problem. I know the tarp idea works because I made a concrete block raised bed on top of stone pavements, I had one layer of heavy duty tarp in between. After one year I had to relocate the raised bed (using a dolley made it easy to transport the blocks, but only one block at a time otherwise it's too heavy). The tarp underneath was like new. Tree roots can puncture the tarp, but not annual vegetables roots growing for just one season. If you have back trouble however, you really should reconsider using concrete blocks and sand which are both very heavy. Unless you want to do it one time and is sure it will be a permanent structure. Consider building a stepping raised bed on a slope, if that will suffice. Another option is "corrugated steel panels raised bed" since they tends to be tall, I suggest looking at some of the designs. It seems a bit more expensive, but will last a long time. You may have to build a wood frame so it's comfortable to sit one and work with, but it's easy. Although will likely need a circular saw to help with the job. Just being picky, cinderblocks are applied more for blocks that may have fly ash and very toxic, you probably mean "concrete blocks". Even with concrete blocks I think if they are made from these factory can have some small amount of toxin just from the manufacturing, though I'm not concerned. The other consideration with concrete blocks is it's made of lime so some people have a concern with alkalinity. My veggies grows well in it though, but I didn't have much luck with tomatoes, though I'm sure there are people who have. If you have a twin size metal bed frame that have wire grid, perhaps putting wooden raised bed on top?