Lots of dirt- MOUNDS of dirt! That is how much dirt you are going to need to fill those amazing Raised Beds that you have constructed. How much you ask? Well first you are going to need to dust off those rusty algebra equations that you told your teacher that you would never need, and get counting. Dirt (or "soil" if you wanna get all fancy-schmancy technical on me), is usually calculated in Cubic Feet- now all you have to do is figure out how much dirt that is.
Now the NICE part of building raised beds that are 12 inches tall is that you can just multiply by 1 and have a nice easy number. So for me, one of my beds is 5x4 so that is AxB and then multiply that by the height of the bed "C", so it is (AxB)C or 5 feet long X 4 feet wide (20 feet) x 1 foot high is 20 Cubic Feet of dirt. Now see how easy that is- if I had used a 8inch bed, it would have been a odd amount of dirt, and most dirt comes in 1 CF (cubic foot- feet?) bag sizes.
So you find out all the CF of dirt that you are going to need for each bed, add the number together, and try to not faint. Just for 4 of the beds that I want to build (and they are not all that big!) it will come out to over 70 Cubic feet of dirt! (yikes!)
Also- when calculating how much dirt you are going to need, always use the height of the boards as a guide. Yes, you may want to only have 10 inches high of dirt in the 12 inch bed, but the dirt will settle a bit, and what looks like 10 inches today, will be 8 inches in a week or less. So get a little bit more than you think you will use to be safe, and if you have left overs, build a new bed, or use the nice soil for top soil for some of your other plants.
You now have several options as to what you want to do to GET your dirt (ahem- Soil). You can get it from your own yard (not a option for me), you can go to the home store and buy LOTS, or you can contact your local Soil companies and see what they charge for some soil, and delivery fees. There are bonuses for each option, and also some downfalls.
When you harvest your OWN dirt (from your yard) it may be the easy and cheap option, but it has a few risks. Maybe it is full of weed seeds, maybe there is fungus from other plants that will distroy and rot your new babies, there will probably be rocks, old roots, and all manner of other items. Now, if you are going to the trouble of getting nice raised beds so that you do not have to deal with all that stuff- why would you just fill it with all the stuff that you want to avoid using in the first place? (just sayin' is all....) Cheap but full of pitfalls...
Option #2, you go to the local home center (or nursery) and buy your dirt in a bag. Easier, but certainly not cheaper. It can run you a few bucks a bag for the "ok to good" stuff (the "really good" stuff will really set you back), and when you see that you will need about 25+ bags of the stuff, it really adds up. "Dirt" is certainly not not "dirt cheap"!
Not to mention that I drive a Honda, and it is HARD to carry that many bags in the car (not to mention hard on the back too!), and unless you have a mondo sized car, you are going to need to take several trip to the home store which is hard on the gas mileage and the pollution factor. Also- you may ask about "what do you do with all those bags!?" I will address that at the bottom.
Option #3, You can call your local soil company and see what they charge for some soil. And you can get really picky about what kind of "soil" you want. Screened, enriched, loamy, sandy.... you name it. Also- most places will deliver a truckload (or however much you order) and will dump it on your drive way or lawn and you cart it from there to your new planter boxes. This will be a much cheaper option, but you will have to do some research on your own, and make sure you have a wheelbarrow, a shovel (and maybe a young man around willing to work for a sandwich and Oreo's for some hauling labor). You can also go pick up the Soil from most places, but you have to have a car that will haul that much weight around and that you do not mind getting dirty.To be honest, I have only built 2 boxes so far, and I used Option #2. It was a long, slow, and heavy option, and it worked for what I needed, but for all future gardening I think that I am going to be going with #3. But I won't judge no matter which option you pick- you gotta do what is best for you.
I am SO not a expert at soil, but you can find good info here or a TON of info here. There are ENDLESS books and websites about Soil- so do some reading on the kind of soil that YOU will want\need based on what option you chose above (and what you will want plant in it).
And if you are curious as to what I used for my planter already, I used Miracle Grow Organic Choice Garden Soil (check it out here). But they want you to mix it with "Local Soil" and not just use it alone, so I DID do some digging around in a weed free soft area of the yard, but it is about 80% MGOGS.
Ok- back to those bags I mentioned. If you should end up with a lot of bags, you can find many uses for them. They are pretty strong and can be used to carry around with you when you are weeding, or use them to cart compost from the composter to the beds. You can save them, and winter comes you can cut a few holes in the tops of them and place them over some plants that need wind protection, and some extra heat and stake them into the ground to hold them in place- or some places will recycle them for you. Worst comes to worst- just don't use trash bags in the house for awhile, and use the bags instead. (just be sure you wash them off first so that you do not track anything in the house!).
What ever option you use, you will also need to check on the PH levels of the soil from time to time, as well as check the nutrient levels to make sure the soil has enough to give the plants so that they don't starve. Since I have used a "bag" mix, all my PH's and food levels are A-ok when I checked them. You can always send your soil samples off for testing, but you can buy a inexpensive PH and nutrient tester and do it yourself. Any Problems that you find can be corrected, but it will take time. You can always find info at This website on how to fix your dirt, or there is usually some info in the PH tests. Any Garden center will have a PH tester kit. They range from a $7 kit to $200 Digital readout fancy stuff- but for the at home mini garden, I will stick with the $7 tester.
So I am sure that you are now wondering when we are going to get to the Plants..... That is next!
I will introduce you to all the new friends that I am planting out in the garden. Stay Tuned!