4' x 8' x .25' = 8 cubic feet per bed. I believe a 40# bag of soil is 1 cubic foot.

Ack! Of course, so easy. 3"=.25 feet

In converting to a common measure I converted to inches. Came up with the same answer but so many conversions from sq.feet to inches to yards I doubted my calculation.

I am buying by the Bobcat scoop which they tell me is about .5 cu yd. Seems about right. I was planning on 1 cu yd. I also have a few small holes to fill here and there in my garden beds. With my compost and OM it should end up OK.

Thanks, mfisch.

Karen

"Came up with the same answer but so many conversions from sq.feet to inches to yards I doubted my calculation. "

The easiest way to do conversions is to use Google Calculator. The key is in how you word it. To convert from cubic inches to cubic feet, you'd enter

X cubic inches in cubic feet (you can also use abbreviations like cu in ft).

You can also use it to convert to other measurements like gallons (if you wanted to know how many 5 gallon buckets you'd need, for example).

Google calculator will also do things like convert kg to lbs, fl oz to ml, sq ft to sq yd, mph to kg per hour, etc. It can even handle some lesser known units, like furlongs per fortnight.

Don't you need almost two cubic yards? 9 cubic feet = 1 cubic yard, and you need 8 x 2 = 16 cubic feet.

1 cubic yard is 27 cubic feet.
1 cu. yd. = (3 cu. ft.) X (3 cu. ft.) X (3 cu. ft.) = 27 cubic feet.

Rather than go through the calculations, you can just downwload this little tool I made for Excel, which comes with a bunch of handy wingdings that will help you out. In this particular case, you would use the mulch/amendment calculator to figure out the volume you need.
Garden Calculators

Thanks, all.

Our friend picked up the soil for us today. He wanted us to have plenty and he wants some leftovers, so he got 3 scoops. That is, I guess, about 1.5 cu yd. Plenty for everyone. Here in suburbia, everybody always needs extra "dirt".

Gargwarb: Funny name, kind of catchy. Are you new to the forum? I think I'd remember that name. That garden calculator does look neat. I'm going to play with it.

Sorry I didn't get back to the thread sooner. Had to take my 84 y/o mother to the doctor, grocery, and do some other things for her. At that age, things don't move fast. I've been gone most of the day.

Karen

kqcrna ....its really a very easy question to answer and you can use this formula anytime you think you have the same excuse to use soil.

Measure the area's width and length in feet...multiple the two. That gives you square footage.
Then, multiply that figure times the depth IN INCHES of soil you plan on using.
The figure you multiply times 3, divide by a thousand.
(multiply by .003)
The resulting figure gives you exactly the required CUBIC YARDS of soil required.

Let's go with 3"

4 X 8 = 32 square feet.....times 3" = 96
Divide by 1000...= .096 X 3 = 2.76 cubic yards.
Now that's the way to do in future.

Now about the cardboard. What's that supposed to be doing. Its September...and if you remember the September song...November aint so far away.
If you are planning to kill grass or whatever under that cardboard...well, OK, it might do the job by next September. It surely will not, cannot, kill anything between now and spring. The method you are using, usually called "lasagna", needs heat build-up and deprivation of sun and water to kill what's underneath.
Unless you live in Florida....and even there, it wont do the job in time, it doesn't stand a chance in you know where to do anything before you will want the patch.

Soil --3" or more, put over the ground, will surely smother weeds/lawn/and anything else, including tree roots, simply by asphyxiation...denying oxygen.

The time to plan a lasagna garden cure is in spring so that the coming summer heat can do its thing.

Jeannie, by any chance you work for the department of finance? Your "formula" is soooo out of whack! (and it's wrong to boot). :)

Length X Width X Depth. (all in the same units of measurement)

4 X 8 X (3/12) = 8 cubic feet

Lloyd

...per bed.

Lloyd

LOL!! It's been awhile since she's contributed to this forum but I think most of the regular posters know to take jeannie7's advice with a very large grain of salt :-) She seems to operate on an entirely different plain than most of the rest of us.

Of course Lloyd's calculation is correct :-) And there are indeed 27 cubic feet in a cubic yard. A half yard should be about right to fill the bed.......perhaps just a touch more.

And FWIW, a lasagna bed can be created at any time. Decomposition of organic matter takes place through the winter just as it does at any other time of year, athough a bit more slowly. In fact, preparing a lasagna bed in fall for spring planting is highly recommended - there is typically sufficient time for everything to 'cook' and meld into a decent planting medium. btw, jeannie, the heat generally comes from the decompostion process itself, not from ambient temperatures.

Jeannie, thank you for being so kind in responding. However, Lloyd and mfisch are right- in any calculation, all values have to be in the SAME unit of measure, whether it's inches, feet, yards, or whatever. And I have no idea where you came up with those numbers of yours.

And I have made several lasagna or interbay mulch beds with terrific results. Fall is my favorite time to undertake this, so by the time I start spring planting around April the OM will be mostly broken down.

And I have killed grass in winter, I think it was February, simply by smothering it with cardboard and weighing it down with rock and bricks. I did this to start a lasagna bed but, in winter, lacked enough materials. By the time I started building layers in spring, the grass was about dead, only from smothering/blocking light with cardboard.

This forum is not only informative. It's always entertaining!

Thanks again,
Karen