Square meter gardening Soil Mix

Question

The Square meter garden soil mix is a third each of compost, peat moss and vermiculite.

I have assumed that in the UK since most of our composts are around 50% peat moss I could just do: 2/3 compost and 1/3 Vermiculite.

It was recently pointed out to me that American English vs British English (AE/BE) might be using the terms compost and soil differently. I would just like to ask if my assumption on using 2/3 compost (50% peat moss) and 1/3 Vermiculite is ok?

NB: extra points for peat alternatives that work well in the square meter garden structure.

Answer 1

In the American English version of the book, it is clear that the recommended mix is 1/3 of mixed, composted materials. That includes things like mushroom compost, composted cow manure, composted poultry manure, and composted kitchen scraps. If this is similar to what you would find in a bag of compost in the UK, and if those bags are indeed 1/2 peat, I would say your plan of mixing 2/3rds compost with 1/3 vermiculite would get you a decent approximation of Mel's mix.

That said, I wouldn't worry too much about getting the mix exactly right. I think Mel has done a great job marketing his SFG method, but there are a lot of other gardeners out there who have experimented with intensive gardening, and it can definitely be done without that exact mix. The mix just ensures that every gardener following the system is starting with basically the same soil, so they are likely to get similar results.

A great (and much cheaper) alternative would be this:

1. Get a soil test done of the soil that is currently in your raised beds. If you are building new beds, remove the grass for the beds and test the soil underneath.
2. Amend the soil as recommended according to your test results.
3. Start adding organic matter to your soil. You can do this by digging in any (or all) of the composts listed above.
4. Plant according to the SMG recommendations. Add compost to a square each time you remove a plant.

You really don't need the vermiculite or peat in most gardens, in my experience. I live in an area with very heavy clay soil. I used Mel's mix in one of my beds just to try it out. My other beds were all built up as I described above. The Mel's mix box did not perform better than my other garden beds.

Answer 2

I agree with michelle...are you adding ANY soil to your mix? It sounds as if it is all compost or organic matter! Plants HAVE TO HAVE SOIL! And I gotta say NO WAY DO YOU USE GARDEN SOIL in pots/bags. Garden soil is a very large ecosystem. It is not perfectly mixed but in the larger picture it is better able to provide balance. There is NO WAY to shovel up a little chunk of this ecosystem and ensure balance for potted/bagged plants. ALWAYS use sterilized soil as a basis for pots and bags.

Making raised beds in your garden would be the best thing, Morgan! You can add compost as you double dig but after that you should never have to double dig again unless it is late fall or early early spring. Sounds like you are doing TOO MUCH OF A GOOD THING and a heck of a lot more work than is necessary or prudent.

I HATE vermiculite. Perhaps it is just the little white spots but organic matter makes ANY SOIL better and wonderful. In fact DECOMPOSED ORGANIC matter is the ONLY way to improve ANY SOIL. Somewhere on this site I have gone at lengths to explain. The only time I will ever use peat moss is to add acidifying organic material to soil. I love the texture and ease of peat moss but it also SHEDS water if it isn't mixed in well and certainly your amounts are way too much.

Have to add that there is this...'hippie' type guy I kinda knew in Seattle, WA. He made his own mix and was selling it to clients/followers/non-gardeners for $100+ per yard. Lots of pea gravel 's involved...for drainage I guess. What a waste of money!! He got rich 'making the best ever soil' as well as using his clients money to 'design' landscapes... but this is not correct management of soil! Out of all the soils I've had to manage, heavy clay did as well as yummy silt loam. I hate this sandy, porous pumice I am struggling to grow stuff in!! But all three; I use raised beds, I mix DECOMPOSED organic matter (compost) when I first double dig and fluff and create my raised beds with trenches along the bottom of these beds to direct excess water. I cover and keep covered with compost all year. Organisms eat this stuff and go back into the profile to POOP IT OUT. The decomposed compost feeds the organisms in the soil and their activity and poop support plants as well as making ANY type soil wonderful soil. DECOMPOSED is the important word here! Kitchen scraps, bark, rock...all are considered mulch. Compost anything that is organic. Compost should mean DECOMPOSED organic matter!!

Gotta stay with what you have for soil and learn the proper management for your type of soil. The ONLY proper way to improve garden soil is adding DECOMPOSED organic matter on top of your beds if they are already established. I've said this before but made a big impression for me as a gardener...if you've got clay and add gravel, gypsum, lime, water and agitate...what is produced? CONCRETE.

Get a soil test, take a mason jar and put a few inches of your soil in the jar and fill with water. Shake, shake shake and allow to settle. This will show you percentages of the different soils that make up your natural soil. Heavier sands will be on the bottom, silt/loam in the middle and clay on the very top. Organic matter will be floating in the water. I don't remember the percentages for labeling your soil but that is out there on the internet. Add to this a laboratory soil test...and you'll be able to make decisions about your soil/plants/garden/management practices that make sense for your soil...and much more chance of success!! You are definitely a gardener, Morgan! This information will FEED you!! Grins...