How much soil or mulch to buy can be a mystery, and it never seems to go as far as we think it should. These are guide lines, not rules because soil settles. For example I built 2 vegetable beds that were 20′ X 4′ and 6″ deep. I calculated I wound need 40 cubic feet of soil for each bed. I wound up using 52 cubic feet in one and 48 in the other, after the soil settled naturally. I didn’t walk on it or tamp it down. That is 25% more than I initially figured, but those beds are level with the top on the 6″edging.
- Bulk soil is measured in yards.
- 1 yard equals 27 cubic feet.
- Think about it as a cube that is 3′ X 3′ X 3′.
- All machinery that can load bulk soil is, by law, labeled as to the volume of the scoop.
- Our machine is 1/2 yard per scoop.
To calculate the amount of bulk soil you need, you need to:
- Figure out how many square feet you want to cover. This is length X width and is refered to as square feet.
- Decide how deep you want the soil or mulch to be, in inches.
Then you can follow this example to figure out what to get.
- For example, you might have 220 square feet to cover and want to add 2 inches of mulch.
- The formula is (220 X 2) divided by 324 (you’re just going to have to trust us on this number)= 1.36 yards.
- Remember to add up to 25% more for settling.
- So by multiplying 1.36 X 1.25 (how to add 25% more) it comes up to 1.70 yards.
- You will probably be fine with 1.5 yards.
The formula is:
- (area in square feet X depth of soil in inches) divided by 324 = total yards (X 1.25 to allow for settling).
- If you need help, just call us at 281-440-5161.
Bulk soil is not for everyone. Yes, it is more expensive to buy bagged soil, but there are some advantages. Bags keep your car or truck cleaner, can be bought a few at a time (as needed), and you don’t need to shovel it out of a truck and then shovel into the flower bed. I don’t have a truck but my small SUV can easily carry 14 bags of soil, which is a yard…and I didn’t have to pay for delivery!
By using the formula for bulk soil (above) to figure out how much you will need, figuring out how many bags it equals, is a breeze. Bagged soil is usually measured in cubic feet, so convert the number of yards to cubic feet by, multiplying by 27 (the number of cubic feet in 1 yard). Let’s go back to our example from above.
We calculated that we would need about 1.5 yards.
- 1.5 X 27 = 40.50 cubic feet (lets round it up to 41).
- The mulch we want to use comes in 2 cubic foot bags.
- We then divide 41 by 2 (cu.ft. per bag) which equals 20.5 bags (lets round it up to 21).
The formula to convert yards to bags is:
- (number of yards X 27) divided by (the number of cubic feet in the bag, of soil or mulch you’re buying).
A few types of soil are measured by weight. Suppliers do this for one simple reason. When anything weighs over 40 pounds, it becomes very hard for the average person to pick up. Guessing how these soils are going to fit into your formula is tricky. We suggest that you compare them to the size of a bag that is labeled by volume. If a bag of top soil weighs 40 lbs, but is 1/3 the size of a 2 cubic foot bag of mulch, you’re going to need 3 bags of top soil to equal the same volume as 1 bag of mulch. If that doesn’t make sense…just call, because I couldn’t figure out how to word that differently.
|Basic guide lines for spreading soils|
|2 cubic foot bag||3 cubic foot bag|
|Depth of mulch||sq.ft.||sq.ft.||sq.ft.||Depth of mulch||sq. ft.||sq. ft.||sq. ft.|
|2″||8 bags||16 bags||80 bags||2″||6 bags||12 bags||60 bags|
|3″||12 bags||24 bags||120 bags||3″||9 bags||18 bags||90 bags|
|4″||15 bags||30 bags||150 bags||4″||11 bags||22 bags||110 bags|
Remember you can always call us or your local independent nursery for help.