Linda, I am not good with estimating mulch myself. I have learned though when I created new beds I needed more mulch and years after I needed less to cover an area.

it is lots of work and that is why I have decided to add as little as possible. I try to add when plants are bigger and sprinkle it sparingly...and I plan to have more flowers so less mulch ground showing in between.

I may not add any next year :)

Have fun!
Karen

There are some questions which need to be asked, in order to give an intelligent answer.

What kind of mulch are you using? Different mulches last for different lengths of time. If you are using the standard shredded pine bark mulch, it will last for more than a year, but it will compact as well as decompose. After a year, it will need to be fluffed up with a rake, and will not be as deep as originally. If you are using woodchips, it will last much longer. Pine straw is probably the longest lasting common organic mulch, and will outlast all of the others, but needs to be much deeper to be effective.

I'm having trouble figuring out the total size of your bed. Is it 78' x 30' with an L which is 30' x 30'? If I have it right, you have 3,240 square feet of bed. Using standard calculations for mulch, that would require just over 20 yards of mulch to cover it all to 2" deep. The common calculation is that 1 cubic yard will cover 160 sf to 2" deep.

I have a lot of beds to cover and I don't worry about the math. I don't spend more than about $15.00 for mulch a year....bales of wheat straw. The rest of the mulch is free...grass clippings dried and spread out as I get! I use Leaf mulch/straw in late fall for winter mulch. All decompose and feed the soil and worms much faster. It does the job and I've been doing this for 8 years! I suppose living in wheat country and getting my bales delivered is an advantage though :)

Oh, I forgot to mention I fluff my much each year when I spread (at last I try to)
I also use the hardwood mulches it seems to last longer but the color fades so I mostly am adding more to make it pretty.
Karen

You know those bales of hay that people buy to decorate for the fall? Could they be used as mulch over the winter?

You have to be careful with bales of hay or straw. Some of them will contain tons of seed which will pollute your gardens for a loooonnnngggg time!

I am with Vera here.
It's been 20 years since I spent on mulch.
I would watch Freecycles, people's bagged leaves (leaves that people have run a lawn mower is best. I put shreded leaves down first, then aged mulch or manure. You should see robins in my garden. The mulch would be scattered all over. :-D

I used to whine for source of mulch & manure on the Soil,
Compost, Mulch forum. lol

Finally, a fellow gardener contacted me and took me to her community recycling center & horse stable. There's a huge sign free fertilizer-anytime in front of the stable. Jackpot!
I have been making a few hauls every year for mulch, compost, and manure. Initially I brought home compost, but stopped it.

Since it's a 50 miles round-trip,I stuff my van with manure and mulch. There are several grades of mulch. I like the most aged one. :-)

Recently I found a source of horse manure only 8 miles from home. But it's next to the woods. The manure is full of weed seeds.

Chicago Park District always offers to mulch people's Christmas trees around the first weekend in January.
I go get the woodchips too. I don't like it much though-too fresh.
Why don't you look around in your community. You'll be surprised what you can find.

Do things little by little so you don't get overwhelmed with the task.
Have fun.

re mulch: Check with your local utility company. A friend told me that the people who trims trees for them will grind them on the spot and deliver the mulch to your house. I haven't been able to connect with them yet, so I don't know, but it would vary with location any way. It's worth a phone call!

My good fortune: A neighbor gave me his huge pile of yucky straw bales. It's 1-1/2 miles away! Some of it's pretty gooey, but with gloves it's ok.