Old Beds

I have two raised 4x8 beds.  This is the third year I've gardened in them--without Mel's Mix.  I originally filled them with Miracle Grow organic garden soil, adding a little new soil each year. How can I adjust the current soil to conform to Mel's Mix in preparation for next year's garden?

Years 1 and 2 were good.  This year the bugs arrived with a vengeance.  I recently purchased All New Square Foot Gardening and realize I have a lot to learn.

My 2 cents.
This is a tough one for many reasons.  The "hard line" answer would be throw it out and replace with MM if your're trying to get MM   
I looked up Miracle Grow organic garden soil to see if I could figure out what is in it, but all I could find is things like "this product contains at least one of the following: forest products, peat humus, OR compost...".  That's not very helpful.

"Compost, peat, and manure" seem to be popular general reference to ingredients, again not very helpful.  

My 2 cents says, count it as a peat and compost component of MM and with nothing really to go on I'd say 50-50.  Mel's Mix is supposed to be equal parts Compost (5 blend), Peat, and Vermiculite (coarse).  Assuming a 6" deep bed, I'd say mix 2" of what you have (counting it as 1" of peat and 1" compost), then add 1" of peat, 1" of compost, and 2" of vermiculite.  

That's going to leave you with the bulk of the material you have left over, 4" per bed based on my assumptions or roughly 10.5 cubic feet per bed.  You wouldn't happen to have a compost pile would you?  You could blend the left over into a compost heap and then cycle it back into the gardens as compost replacement/refurbishment in the future.

That's almost like starting from scratch and just making pure MM anyway.
Option #2 with the focus of trying to save money or what you've already "invested".  Vermiculite would be my guess for the material you're most lacking based on what I saw for Miracle Grow components.  The second thing I think that would be off (relatively speaking from the aspect of "be like Mel") is a blended compost.  I suspect your compost component is a manure and "forest product" (leaf, wood?) blend.  
So, again assuming 6" depth.  Use 3" of what you have, add 2" of vermiculite, and add an inch of new compost.  Try to find compost that does not have manure or wood base to help increase your "blend".  An inch of compost is only about 2.5 cubic feet over a 4x8 bed.  You can get compost bags of about 1.5 c.f. maybe even 1 c.f.  So, you may be able to get a mix of something in that 1".

ZMoore - I like your response and will use one of your suggestions for my pre-MM beds (2).

ZMoore, thank you so much for your prompt reply.  I'm very grateful for such clear and concise options.  I was so glad to hear that what we have may still be salvageable.  Will certainly give it a try!

Hi CT23Yankee! Welcome from Atlanta, GA!

I have to agree w/ ZMoore. Just keep in mind that you can amend slowly. That might be better on the bank account...

You might also look at Jimmy Cee's experiments in microbes. Jimmy - where did you post those?

Yankee,  Welcome to the Forum from California!  

What to add and how much depends.  How deep are your beds?  How deep is the remaining fill?  Do you have weed fabric underneath the fill?  If not, a bit of dirt may have been pulled up into the fill each time you pull spent plants.  Can you post a photo or two of the fill and boxes?

Here are my 2 cents:  There is plenty of peat already, so you don't have to worry about that.  If you have 3-6" of fill and plenty of head room, add a minimum of 1" of vermiculite ( if you did not put weed fabric down) and 2" of mixed composts, stuff that is free of any form of peat and wood.  Wood (forest products) are often used in making commercial compost but the wood should be broken down.  You can screen the bagged composts to remove remaining wood pieces using 1/4" hardware cloth.  "Search" screen or screening for more info.  If you Search compost, there are 300 threads available.  That's probably because Compost is the more important part of MM.  Manure compost, worm castings/vermi-compost, seaweed / kelp, crab / lobster compost, mushroom compost, veggie-based compost, leaf mold, etc.

Here's the microbes thread.  Great reading, especially for winter.  Gets one all excited for spring.  https://squarefoot.forumotion.com/t20218-microbes-you-gotta-see-this-one?highlight=microbes

Hey!  Welcome Yankee!  

I am not a math person, but I would be amending with vermiculite and compost.  Really good compost.  And lots.  And start a compost pile! LOL!  

Because your Miracle Gro beds are 2 years out, they are exhausted nutrient-wise.  My guess is (and having used this myself in many containers) this stuff is a one season situation.  After that, you have to help it out.  

So can you take some up close pics of the mix still in there?  Optional.  But might help the more scientific amongst us!  

Again, glad you found us!  Post often!  Check out the regional forums to see where you fit in weather wise!

  yankee  

from Kelejan in British Columbia

Good to know that you need to know more.  Many of us start with Miracle Grow due to lack of knowledge and the effects of advertising.

I am amazed at some of our gardeners who knew little about gardening to start with and now are producing lots of lovely food.