So, I am starting a backyard raised garden ... it's 4'x12'x12in high ... I am a complete beginner, living in north Texas

So far I have the box constructed, with 1/2 in hardware cloth to keep rodents from burrowing underneath and will be putting cardboard on the bottom, on top of the HW cloth (i'm told this attracts worms, which I apparently want). This garden should get about 7 hours of full sunlight per day.

I know I'm late getting started and I will probably only get one crop this year. I plan on raising primarily vegetables.

I plan to fill it to about 10in depth with quality organic soil. At my level of experience(I need simple!), I think it's probably best to go with something pre mixed, and (maybe?) mix in some varied compost with it.

So I've found some packaged soils I'm likely to settle on, which are:
--Miracle-Gro Raised Bed Soil (labeled 100% organic)
--Ecoscraps organic garden soil (orange bag)
--Natures care Organic raised bed soil
--(maybe) mix in some Just Natural organic mushroom compost and/or Happy-Gro 100% organic compost.

Thoughts? Am I on the right track here? If I do mix in some compost, what ratio should I consider? 10%? Photo attached.

Mushroom compost is awesome.  It is hard to tell you ratios without knowing if those garden soils have anything added in already or not.  If not, I would say 5:1 or 4:1 ratio of soil to compost/amendments for starting is good.

The main concern I may have with your plan is putting the cardboard on top of the cloth.  I really do not know if that will slow decomposition of the cardboard or not.  It seems like it may.  Someone else with specific experience may be able to chirp in on this.  The idea is for the cardboard to decompose in one season.   The cardboard does not attract earthworms, but does help in smothering the grass, and then kind of opening up a border for the earthworms to move up into the bed.  I am not sure if the openings in that cloth are too small for earthworms to want to crawl up in between the holes or not.  

Matthew Rupert wrote:Mushroom compost is awesome.  It is hard to tell you ratios without knowing if those garden soils have anything added in already or not.  If not, I would say 5:1 or 4:1 ratio of soil to compost/amendments for starting is good.

The main concern I may have with your plan is putting the cardboard on top of the cloth.  I really do not know if that will slow decomposition of the cardboard or not.  It seems like it may.  Someone else with specific experience may be able to chirp in on this.  The idea is for the cardboard to decompose in one season.   The cardboard does not attract earthworms, but does help in smothering the grass, and then kind of opening up a border for the earthworms to move up into the bed.  I am not sure if the openings in that cloth are too small for earthworms to want to crawl up in between the holes or not.  

Thanks! Actually I have abandoned the idea of the cardboard, as I am worried about the chemicals that might be in it. I can always add earthworms, or (I've read) sprinkle cornmeal at the bottom, add soil, and then sprinkle more on top.

Can you comment on using prepackaged organic soils? I've considered using a mixture of the brands I've listed, diversifying my soil portfolio, as it were

Hi Kerry, welcome to permies. You're definitely on the right track. I garden in raised beds, and I found a local nursery that sells a soil blend that they mix on site at their facility, and it's a blend of topsoil, wood chips, sand, compost, and earthworm castings. I purchased that by the yard and they loaded it into the back of my pickup and I just backed my truck up to my beds and pushed it out with a steel rake. May I suggest looking into whether a local nursery in your area offers something similar, as it will be a fraction of the cost of buying bags of soil. It looks like you'll need about a yard and a half to fill your raised bed, and keep in mind it will settle like 30% in volume. If you fill the bed 10 inches deep, I guarantee you it will be considerably less in 6 months. If you fill the bed with quality soil, the earthworms will come. They will find it. If you want to add some extra quality compost, it certainly won't hurt. You mentioned you're a beginner and I would like to make two more suggestions. One is, while you at it in the beginning, consider adding minerals to remineralize this soil. Products you can find include, but are not limited to, glacial rock dust, sea-90, azomite... Adding more minerals to the soil will grow better, more nutritious crops. The second recommendation is once you plant whatever it is you choose to grow, mulch your raised bed. Mulch will keep the soil from drying out and baking in the sun, and it will keep the soil from developing a crust, which inhibits water flow and the soils ability to breathe. You can use wood chips if you want, I currently use straw. Straw is cheap and one bale will cover that bed. Keep in mind not all straws are created equal. I'll bet dollars to donuts a bale from a big box store like Home Cheapo is from genetically modified wheat, and that straw is laden with chemicals that will cause problems in your new raised bed. Perhaps see if there is a local farmer who grows wheat without chemicals. It doesn't have to be labeled organic, as I was able to find a local guy who wasn't certified organic but didn't spray chemicals and that straw has worked out well for me. And again, it doesn't have to be straw. If you find a nursery that has that soil blend, they'll have traditional wood chip mulch by the yard too, and I bet they'll sell you a half yard, and you'll have some leftover, which if you have a spot somewhere off in the yard, dump it in a pile and it will slowly decompose turning into good stuff that you can add to your raised bed come next spring.

One more thing: this fall when the garden is done, don't pull dead plants like a tomato plant. Grab some shears, and cut off the plant at or just beneath the soil level and leave all it's roots undisturbed in the soil to decompose, depositing vitamins and minerals in the roots back into the soil for next years crops and also providing food for microbes and fungi living in the soil. I'm crazy about gardening and growing my own food, and I want you to be successful. Putting time, effort and money into a new garden just to have problems and not get good results can be very demoralizing and defeating. By doing simple things like mulching, it will provide habitat for all sorts of bugs and worms that will make a home in the soil and aide in creating a healthy soil food web. And that will bring you success and a smile on your face when you go pick delicious healthy food out of that raised bed, and you'll likely get hooked on gardening too

I would go to the local landscaper, often they deliver it is far cheaper and no packaging involved. No mushroom compost!!! It contains salt and I have very bad experiences with that. You can make some more beds, really the expensive structure is not needed and I find working around it awkward.