A good soil mix would be 45 percent sand, 25 percent silt, 25 percent clay, and around 5 percent organic matter, although I prefer 6 to 8 percent OM. If you can't find that soil mix just about any soil with that 6 to 8 percent level of organic matter would work.

I think that it's a shame that some people have become afraid of their native soil. In most instances, THAT is the best soil most of us should be using! I have very dense, red clay and have found it to be an extraordinary medium for all kinds of plants. From trees to turf, plants thrive in my soil with little to no amending.

Adding a disproportionate amount of organic matter is never a good idea. Replacing a large amount of soil in a given area is very rarely necessary.

Kimmsr 's suggestion is taken directly from old soil science textbooks of what is described as 'the ideal soil '. The ideal native soil. That ideal fictitious soil is cited in textbook after textbook as a guideline only. It's not a commercial mix. I did order a load of top soil when we were reconfiguring our front yard and we were sent the most beautiful sandy loam. Scrumptious! It would have satisfied the textbook example.

In my vicinity, Stella D'oro lilies are ubiquitous. That crayola orange color is not an easy one to work with. There are other options for a long blooming or repeat blooming daylily. "Happy Returns " is a lemony color with similar blooming capacity as Stella...just as one example.

The daylily suggestion is offered as opinion only. You may really like the color of Stella D'oro and if so.....go for it! Your yard should make you happy everytime you look at it.

I've never understood why anyone would replace great amounts of soil in their gardens unless the soil is badly contaminated which doesn't seem to be your situation. IMO it's much easier and better to just amend what's there. What I'd do is just dig in that "practically-composted-horse-manure and straw" and plant. If plants show signs of lack of nitrogen you can address that at the time with an application of alfalfa pellets or tea or just use it when you plant as it helps avoid transplant shock and is a gentle fertilizer/soil amendment. I wouldn't use Miracle Grow as IMO there are many much better options.

If you know you have a tendency to over-water you might try digging down a bit to see how dry the soil is a few inches down before watering. Also once your bed is planted you can use a natural mulch to conserve moisture so frequent watering may not be necessary.

A perennial bed with only Asiatic and Stella D'Oro Lilies will not be as interesting as one with a greater variety of perennials, annuals, and/or shrubs.

BTW Stella D'oro lilies are yellow, not crayola orange. That's why they are called D'oro which means golden. There are many perennials that will look great with them. You might post a pic of your garden area on one of the gardening forums depending on your climate or chosen gardening style and ask for suggestions. "The Cottage Garden forum" is a great place if you like that style.

What luckygal said ... just dig in some of the composted horse manure. Whack any unusual dirt clumps with the back of a shovel to bust them up and toss them back in.

Around any house you will find "domestic debris" - nails, toys, bits of pottery. it's not going to hurt the plants.

Daylilies - Stella D'Oro and others, are famous for being totally not fussy about the dirt they grow in.

More important is the amount of moisture - I'm not familiar with Asiatic lilies, but some lily varieties can be very fussy about soggy soil. Make sure you plant things with similar watering requirements or you will drown some while others die of thirst.

Down the road from me is a landscape supply company that makes that ideal soil that you can buy for $22.00 per cubic yard plus a delivery fee (depending on distance) in minimum 5 cubic yard loads.
However, as I noted above any soil with 6 to 8 percent organic matter will also do the job.

btw, unless you are growing the dwarf Asiatic lilies, the Stella D'Oro daylilies will be significantly shorter :-) They are a very compact daylily, only growing about 12-15" tall. Most Asiatics get at least 30-36", often taller.