The reason(s) amending of soils in small areas is counterproductive do not vary with the type of soil. Sandy, silty or clay-like, it makes no difference. You do not want to install plants in pockets, strips or zones of one soil texture surrounded by soil of a different texture, as this sets them up for likely problems with how water moves into and out of the soil around their roots. In the case of plants to be left in place for many years (or indefinitely) without lifting and re-planting there is no point in incorporating organic soil texture modification materials (bark, compost, peat...) even if the bed is large enough to minimize or eliminate water movement problems for most of the plants - once the amendments decompose the effects they produce will be lost. Inorganic amendments like perlite and sand do not decompose but enormous amounts of these have to be added to change a heavy soil into a light one. And if too much is added then a droughty and infertile (leaching) situation may be produced, that may be more limiting than a heavy clay-like soil. The most straightforward approach is to choose plants adapted to the existing soil type and plant these in wide, shallow holes dug out of that, loosening it over a wide area beforehand and mulching well afterward. The most satisfactory mulch for woody plants appears to be clean wood chips. If arborist wood chips available nearby tend to have bramble stem sections or other undesirable material mixed in then play chips from a local dealer may be the best bet. Ones we obtain here as cedar play chips are very nice but have become quite pricey, as far as it goes.

I have done this many times: Mow the grass area with a mulching deck. Wait for a couple days until the clippings turn yellow. Dig the bed, single or double digging. Either bury the grass roots, or expose the roots to the sun and do not let the roots get water. This way, you try to kill all the perennial grass. Do not worry about grass seeds. There are many many seeds in the soil anyway. Use mulch to manage the seeds in the soil. Wait a week or two, continue to kill the perennial grass/weeds. Amend the soil if you can. The garden should be ready when most of the perennial weeds are killed.

Don't rototill. Yes, every magazine and all the books tell you to rototill, but don't. I used to work with in the grading business and we just sort of laughed at the recommendations to rototill. The problem is unless you have a rototiller on a tractor, a human being cannot hold a tiller perfectly level for even 1 foot of travel. You end up with an uneven subsurface. When the level surface settles (it takes 3 years), you are left with the profile of the original uneven subsurface. Don't rototill. If we can assume your soil is intact and did not wash away with the storm, then at most you would need minor leveling...if that. Preparing the surface can be done with anything you can drag across the surface to loosen the very top of the crust. You need only slightly loosen the surface. You will be rolling the seed down into that loosened surface after you scatter it. A piece of chain link fence with some weight on it makes an excellent drag. Drag it in all directions. In the previous efforts to establish seed, was the area watered briefly, several times per day, every day, for 2 weeks? It sounds like it was not. Seed needs continual moisture to germinate so you have to keep it moist. If it gets that, it is hard to prevent it from sprouting.

How to Grow the Tomato and 115 Ways to Prepare it for the Table | Vegetable Resources - Vegetable Resources Aggie Horticulture Network > Vegetable Resources > Additional Resources > How to Grow the Tomato and 115 Ways to Prepare it for the Table Seems to work. I'll check again tomorrow. OP was 2007. 2007 seems to pop up a lot. It must have been a good year for Gardenweb. Does that mean there was bad weather or gardeners?