New User from Chicago area - question about compost

Hi there everyone, so excited to be here.

After the last three years of my garden being horrible, I found SFG.  Bought the book and here I go.

Please help a 71 year old newbie with advice.  5 years ago, I built two 4 x 8, 12" deep raised garden beds.  By raised, I mean there are 4 legs (each about 3' tall) on each of the 8' side to support the weight of the dirt  so that I can garden and weed standing and not get on my knees.

The book says I need 32 CF each to fill those babies.  That's a lot of dollars.  I have good dirt in the beds from a landscape company.  Can I just remove 6" of dirt and add  6" of Mel's Mix to the top to bring up to my 12" depth of the beds?   Bottom 6" dirt, top 6" MM.  Would that work?   It would save me a lot of money.

Also, compost.  I have read that I need a variety.   I know that Black cow is good, but what other kind should I look for?  Or not buy?

I already have 12 CF of coarse vermiculite and 9 CF of 'compressed' peat.   I am told that the peat will 'fluff' out to the 12 CF I need.

I am in Zone 5 and it is in the 30's for the next few months so I cannot do anything now but get my things ready

Thank you so much in advance.

Dani from near Chicago

danieggert wrote:The book says I need 32 CF each to fill those babies.  That's a lot of dollars.  I have good dirt in the beds from a landscape company.  Can I just remove 6" of dirt and add  6" of Mel's Mix to the top to bring up to my 12" depth of the beds?   Bottom 6" dirt, top 6" MM.  Would that work?   It would save me a lot of money.

Yes, you can remove the top 6" of soil and replace it with 6" of MM. All of my beds are 18" high, and I have the first 12" filled with various things, including top soil, and topped with 6" of MM. They are all thriving.

danieggert wrote:Also, compost.  I have read that I need a variety.   I know that Black cow is good, but what other kind should I look for?  Or not buy?

I already have 12 CF of coarse vermiculite and 9 CF of 'compressed' peat.   I am told that the peat will 'fluff' out to the 12 CF I need.

The one thing you must watch in bagged compost is how much of the content is peat or wood chips. You want as little of those things as possible, but if the compost has a lot of peat in it that amount must be subtracted from the other peat that you add. Some composts, such as mushroom compost, is largely made up of straw, sawdust, etc.

Composted manure is good, but limit the amount of it that is used, and if you use worm castings limit those to 10% of the total.  Get as many different types of compost as you can reasonably afford from local sources.