Well, first of all try and confirm that it really is true that the iron content of spinach has decreased dramtically. Ask "Pepper Joe" for his source for this information. A lot of this belief lacks any confirmation (that I have seen) and is based upon rumor and speculation. I am not saying it isn't true, I am saying I would verify the source before accepting it as truth. OK, so you want to grow spinach and ensure it gets plenty of iron. First, iron is a micro nutrient meaning plants don't need much, but they do need some. Very few soils are iron deficient so no supplimentation is necessary in most cases and if you are adding organic matter to your soil you have no need to worry about it. Iron is bound to the soil in a form that plants cannot use if the ph is too alkaline. Do you know the ph of your soil? Most all veggies prefer soil that is slightly acidic to neutral and alkaline soils are trouble. Generally this problem manifests itself in iron chlorosis, but other forms of nutrient deficiencies also occur in alkaline soils too. Another issue is too much phosphorus. This is one problem with using manufactured fertilizers, but it is also a problem with fertilizers labelled according to their NPK values regardless of origin. I do not know what soil type you have, but clay soils and soils with good organic matter are almost never deficient in phosphorus. It is a basic ion thing. Negatively charged ions are attracted to positively charged ions. Most plant nutrients are positively charged ions. Organic matter and clay particles are negatively charged which is why clay soils are usually fertile (the nutrients "stick" and is also why soils rich in organic matter retain nutrients better than soils lacking organic matter. A big exception is nitrogen in nitrate form which is negatively charged which is why nitrogen leeches from soil and becomes a pollution problem. An excess of phosphorus prevents assimilation of iron and zinc. Unless a soil test reveals a lack of phosphorus, don't add any in the form of store bought fertilizers if maximum iron uptake is important to you. Anyway, these facts have led some to conclude that the use of too much fertilizer over the years has resulted in crops which no longer contain the same nutritive value as they used to when soils were more 'balanced'. Long story short is ask those who make the claims for their sources. If the plant looks healthy it is almost certainly getting enough iron.

Andrew, Absolutely go out and purchase some good quality soil to fill those beds, in addition to any organic matter you can scrounge up. As was previously stated, the mineral component is the skeleton of the soil. While organic matter is important for buffer capacity, water holding, nutrition, structure, etc., it is still just a part of the whole soil system. You've got to remember that the organic fraction is continually lost through mineralization. When the majority of your soil is organic matter, this results in significant loss of soil volume annually. Thus, you must add significant amounts of organic matter annually. Filling your beds with good, purchased soil will provide a near permanent skeleton for your soil, to which you can add organic matter till your heart's content. Another advantage to filling with purchased mineral soil is faster heating in the spring. Compared to organic matter, the mineral component has a higher heat conductivity that permits faster warming in the spring. Warmer soil earlier will allow earlier planting. You may also be able to find good silt loam depending upon your location in PA. If you're lucky enough to find it, silt loam provides the greatest plant available water holding capacity of nearly all soil textural classes (maybe all I forget off-hand.) Be extremely picky with what you buy and check it out for yourself. Whatever you buy, you'll be stuck gardening in it unless you dig it out and replace it. Further, check out what you're buying before the fact. My sister bought "screened" soil with clumps of clay in it. Use the 'feel method' for determining soil texture to see for yourself what the texture is like. It takes some practice to calibrate your fingers, but becomes a handy skill once you get the hang of it. Good luck, and update us on how you're doing. Here is a link that might be useful: Soil Texture by Feel

Starting indoors means they are also protected from insect or bird damage, disease, and that you have better control over moisture. Its still advantageous to start plants indoors even if it is "warm enough" outside. As long as we are talking about plants that tolerate transplant well.

Thank you all for your advice and comments, it’s exactly what I was needing to hear. We re-walked the land today, and we have a few other options for propriety placement, that would naturally take better advantage of the views. We do own the land that is blocking our original intended spot’s view, so some downgrading could be an option, if we end up going with that spot. We are on a very unique peninsula of the canyon rim, with no other lots or properties behind us, so, we are lucky to not have to worry about blocking others’ views. I like the idea of making more of our living spaces upstairs - I definitely won’t be giving that prime real estate to the kids’ playroom, as I was originally thinking. Thanks to your advice, we will start the process of hiring an architect soon, and will start the process with an architect vs a builder. Thanks again!