Composted horse manure may be great for growing mushrooms but it's not "soil" and it won't grow decent vegetables.

Take care of the "lawn remnants" (and weeds) first and then dig a trench 12 inches deep where each raised bed is to go. Mix some of the compost with the soil at the bottom of the trench to provide a transition layer. Then place each raised beds in place over each trench and mix about 1 part compost with 1 part native soil to fill the trenches and raised beds.

The key will be to take care of the "lawn remnants" and weeds first. Otherwise, you WILL be fighting them while trying to grow veggies.

Joe

Joe,

Thanks for your reply. I was hoping for the worms and microbes to take care of the sod instead of my puny muscles.

I have looked at the Serrano website, it sounds like a good product, I have been thinking of buying some for my parent's garden in Laguna Beach. Let us know how it works out.
I have done a workshop with one of the premiere organic farmers on the Central Coast, and she uses composted manure on her tomatoes, pumpkins and squash generously and I followed her guidelines with success in my little garden.
However, root vegies, such as carrots and beets, do not like such rich soil. You will learn as you go, different vegies need very different conditions to flourish,( what a celery loves tomatoes hate ( constant water ))
How thoroughly composted is what you will be getting?? If it is composted all the way to black humous-y small particles like soil, you should be able to fill your boxes up with that and have at it.If it is still recognizably horsey, then a bit more caution is needed!I would think about adding some good bagged mix on top.
I garden in Los Angeles, at a community garden where we have a great source of composted horse manure made with wood chips which is still fluffy and stinky , and also a more finished compost which is garden cuttings,and manure composted for longer until it is very black.
Even in our garden there is NO consensus on how to use the manure and compost, almost everyone has their own theory. And the garden is full of happy vegies! Everyone doing it their own way. You will need to find what works best for you.
In my plot, I did the whole double dig, mix in the compost and the manure routine, it is HARD WORK.I used a lot of manure, and the plants seemed to love it. I planted the tomatoes into holes filled with the manure, it was a jungle of tomatoes.Then in some areas I also added a top layer of good bagged planting mix.This is where I planted the root vegies. I like Happy Frog or Whitney Farms. Yes, it is expensive, but I have a small garden, and I wanted the best chance of happy vegies.
It is a lot of work to turn the soil like that,and if you are doing raised beds/boxes , I don't see the point.
In your case, if your lawn was free of major weeds such as nut sedge or burmuda grass, just cover it with cardboard or newspaper, and go ahead with filling up the beds. Poke through the sod with a heavy garden fork, this will open up for drainage. I would make the edge of the walls higher than 8" though, at least 12" if not higher if you can afford the lumber.
If you can afford to fill the boxes with all new, purchased materials, that would be the best. Adding any of the soil from your garden is just adding problems, possible dormant weed seeds, nematodes, and soil borne disease.
With out seeing the Serrano compost, I can't say for sure, but if it is like what we use, still a bit rough and rich, you can fill the beds with that, grow only the plants that love rich compost this year, which would be tomatoes, squash,peppers and flowers such as zinnias,marigolds,dahlias, sunflowers,
let the worms and such do their work, and I think you will be pretty happy with it. Add bagged soil as you want or can afford, next spring plant the root vegies etc.
Happy gardening

I bought 20 cubic yards of compost from Serrano Creek and its the best compost I ever bought bulk. I planted my Zucchini in a six inch layer of the stuff and I am getting fantastic yields off the healthiest looking plants I ever grew. I put some in each of my tomato planting holes and a layer around each of them and my tomato patch looks like a jungle the plants are so big and healthy looking. I also put an layer of the horse manure compost around each of my fruit trees and also rototilled some of it into my clay soil.
The trouble is the word is out on Serrano Creek and the law of supply and demand has kicked in. When I bought my two truckloads, one last year and one a few months ago the price was $8 a cubic yard plus $35 to get it delivered to me (about 20 miles one way). Now they want $12 a cubic yard and $80 to deliver a truckload. That's why I never mentioned the name on this message board because I knew the price would go up when the word got out, and apparently it has.

I get my horse manure free from my next door neighbor who has 5 horses. He brings it over and piles it up in my side yard(I have 5 acres) for me to use as I need it. I try to use the oldest first. For most of my vegetables, I lay down a 6" layer and plant right in it. The tomatoes,peppers, squash,green beans and berry bushes love it. I just love it. It is nice and fluffy, with no moisture in it. I will occasionally find a "horse apple" in it, I just put those into my compost pile. The worms really love it.

I would be concerned that a layer of newspaper 8 inches below the surface will create a root barrier and/or hold water, creating unhealthy conditions in your beds. I would look for another way to get rid of the lawn. I hate to promote chemicals, but Roundup would kill most of the lawn plants (maybe not all the weeds first time) and wouldn't create a barrier. Definitely avoid 'home remedy' ways to kill the grass such as vinegar, salt (!!), and similar things that are actually a lot longer lasting than Roundup. One non-chemical way to do it it to water thoroughly, then lay black plastic over the place where the beds will go for a few weeks in summer. The grass will be dead, then you can pick up the plastic and build your beds.

Follow up here-

I got 10 yards of beautiful compost delivered two weeks ago. Now instead of a front lawn I have beds with 6" to 15" of compost on top of the Roundup-treated lawn. In areas where I planted I made a planting mix of 1/2 compost, 1/4 perlite, and 1/4 garden soil.

After putting as much compost as reasonable on my existing beds, lawns, and the new beds I still have about 3 yards that I'm going to store under a tarp for future use.

I started a new garden blog:

Here is a link that might be useful: Jim's Garden Blog

Hi Jim,
I checked out your blog, and the yard looks just beautiful. I especially love the bench.

I love your neighborhood. When I was in grad school I lived in Long Beach and I really enjoyed it.

Renee