Is it okay to combine garden soil with Mel's Mix Compost?

Also what is the growth/yield difference between 100% Mel's Mix against garden soil and a mix of Soil and Mel's Mix? I am in the North of England (pretty cold except for two weeks a year). Thanks.

I don't do it.

The biggest attraction to SFG for me was low maintenace, weed free gardening.

Mixing garden mix in there may contaminate it.

Probably a dozen other reasons why not to ...but thats why I personnaly don't.

Hi, from California USA, do you have a compost bin? Mell suggest in his book , to replace the soil with that from your compost, so if you started off with just MM only in the beginning, I guess it would be ok to mix MM and well composted garden soil to start with. As for the yeild , only time will tell ! maybe some one else here has done that but my guess would be it would probably be the same for quantity but as for quality , I'm thinking straight MM has more nutrients. Hope this helps, happy gardening !

I don't know the yield differences. I mixed in some garden soil because I had to. Result, a few weeds. Don't know otherwise any impact as I have nothing to compare it to. If you can do pure MM, that's great, but if you can't, please don't let that stop you from gardening! (And welcome to the forum! )

Thanks, everybody, for the kind replies and the Welcome.

Where I am, there are more weeds than grass, and my thoughts
were that no matter what I'm growing in, I won't escape a few
weed-seeds so weeding is inevitable. So I wanted to do a cost/benefit
of the cost of Mel's Mix (or similar) and soil against expected yields.

Perhaps the best thing for me to do is three beds: one for Mel's Mix,
one for soil and the last for a mixture. I will be able to determine for
myself the difference in yields. I had hoped someone might have already
known this and so save me a year from finding out.

I'm also considering putting a bed under a removable cloche/mini-polytunnel
to see how that turns out.

Sounds like a good experiment, Kevin. I know that Tim did a side-by-side comparison of tomatoes in MM and regular soil and the results were dramatic. Can anyone link that in? I'm not sure where to find it.

I must say that my plants have grown quite well this year, and are continuing to do so. Who knew I'd still have summer plants going strong at the end of Sept!

my 2 cents worth.
I would not use JUST the existing soil. If you do not have enough to use strictly MM, YOu can mix it into the existing soil. Mel use to do it all the time and had wonderful results.
He just has a new way of doing it now days.

In my SFG, I have amended the soil because I could not afford to be a purist. We had just bought a tiny fixer-upper and there are so many things that need work. Budget constraints dictated that only the cold frame be pure MM and the garden be a mix. I look forward to the day when I can have all of it on MM but for now this is how it is.

In the cold frame I have very little in the way of weeds. Only a few that get blown in when the top is open and some grass that is very tenacious and finds it's way through the smallest cracks. The garden has a bit more but considering the weed patch that was here when we moved in, I find it surprising there really isn't very much. I do mulch with shredded leaves and grass clippings so I know that helps.

Don't despair if you can't do it all the way you would like. I love your experiment idea. At the risk of being sacrilegious, I think it is better to use a modified Mel's Mix than to not garden at all. (sorry Mel! )

GK

Yes, indeed - thank you all for your time and your thoughts - I do appreciate it very much.

I am already aware of the pro's and con's of using Peat-based compost mixes against just soil. I grow veg for 4 families with disabilities and being disabled myself my finances are such that I really need to make sure what I do is cost-effective, which is why I asked the question in the first place and am delighted by the answers.

Just now I have started a wormery and I have added a few extra things which I believe will give me a great start on my sfg efforts. I think I just might do a grow diary, so we can see how it goes along.

Thanks, again, guys. I appreciate your thoughts and your time to reply.

Kevin, that is an amazing story, and bless you for what you do!

Lol! Thank you!

It's not as amazing as it is desparate - really believe me.

Hello Kevin, and welcome.

I live in an almost opposite climate from you -- very hot and dry for months on end. I found MM dried out too quickly on me and was then too difficult to rehydrate, so I've started mixing in some sandy loam soil and pure compost (which I make myself) -- 1/4 soil to 3/4 compost into the MM I already have in the beds. I don't have any data yet on the difference in yield, but the one with some native soil is now holding water much better. And the weeds are easy to pull when small, so that really hasn't been a problem.

Like others on here, I wouldn't suggest using just soil -- at least a 1/2 and 1/2 mixture with compost, or optimally, if you can afford it, 1/3 soil to 2/3 MM or compost. Please keep us informed on your results.

You can be sure I will - I believe in putting in as much as I take out of fora.

Thank you all for your comments thus far.

Over the next fortnight I shall prepare my sfg beds and take some photos
to make a diary of my progress. I shall post these here.

Over this winter I shall also be making some vermi-compost and reading up
on other compost types. Then I shall assign a bed to each substrate-type,
drill some seeds and see how things grow while maintaining the diary here.
I imagine I shall update the diary once a month as I have other projects on
the go.

It's a fascinating hobby which occupies my mind nearly constantly. If I'm not
in the garden I am reading up about it. It just amazes me that the "numbers" aspect
is not more rigorously applied. Each to their own, I suppose, as I imagine
such detail might take the enjoyment out of gardening for some.

I also hope to offest the seeds costs a bit by selling off excess worms to anglers
and excess vermi-leachate to gardeners.

Applying numbers to something like this is difficult. Hypothetical example: Does my worm compost have the same nutrients, in the same proportions, as yours does? Doubtful.

What little I have seen about hydroponics IS all about the numbers, and mind-bogglingly so. And certainly there are GDD (growing degree days) and so forth.

For large scale food growing... something as profitable as that WILL, by definition, have a science behind it. Agricultural / horticultural science is big business... but for a typical homeowner like myself, that science is beyond me.... and possibly not applicable, either. Since I'm growing in a SFG, I can't exactly fine-tune the requirements of each square to the plant that happens to be growing there at that specific moment, the way you might amend a few acres to a specific crop.

I don't think there is anything wrong with this method, it's just different. Overall I've gotten a great harvest and I am very happy with it... and it's easy enough for anyone to try, which I feel is an extremely important aspect.

I do applaud your desire to approach the matter systematically, though, and please do share your results with us! There is no such thing as too much information.

I am far from an expert, having started SFG just this year. However, i grew up with a large backyard garden and have done a decent amount of gardening.

I live near a river and have very very clay like soil. However, I have put some local top soil in a couple of my boxes this year, mixed with MM. I have a couple of boxes that were a half blend of local top soil/mushroom compost, and the remaining half mel's mix. I have several boxes of pure MM. And a couple of boxes that started out as 1/2 and 1/2's but I dug out and added more MM.

So here is what I can tell about the differences between the boxes. The boxes that have half of the soil/mushroom bedding and half MM produced noticably smaller root veggies. Radishes, carrots, etc did not grow as well. I think this is for two reasons, 1- the soil is more dense due to the clay and resists the growth of the root veggies. Also, those boxes seemed to be more nitrogen rich, so greens grew very well. ON the other hand, plants that need some structure, or grow tall, seemed a little happier with some of the clay soil mixed in. I have a jalapeno that falls over when it rains (OK I finally staked it out with about 6 stakes)

anway... for a quick break down

1) Pure MM = best for root veggies, but yields great for just about everything. Tall plants will need additional support
2) Mostly MM, with a little soil added = best for tall plants/shallow root systems. Little noticable yield difference, although I did dress these with a little bone meal before doing the fall crop, and it definitely helped
3) Half MM/ Half compost and soil mixture. = good structure, but lower yields, and needed quite a bit of amendment with bone meal and some other organic fertalizers. I will probably dig these boxes partially out next year, and add more vermiculite and peat moss. No need to fully replace things.

So, in my case, and with the local soil condiditon, I did have good luck with mixtures. I wouldn't let more than 1/4 of the total be soil or it just gets too dense. Like I said I have very clay heavy soil, so perhaps you could go up to 1/3 soil if the local dirt is light or sandy.

Wow.

double wow.

Thank you very much - this is the kind of info I need and is super-valuable.

I shall be adding my findings as my sfg project goes along.

Many thanks, again.

Kevin

Ordinary garden soil has thousands and thousands of weed seeds ready and willing to sprout when the conditions are just right. Square Foot Gardeners do not like to weed, so do not use your native soil. Start with perfect soil from the beginning (1/3 peat moss, 1/3 coarse vermiculite, and 1/3 blended compost consisting of at least 5 ingredients and treated so the weed seeds have been killed). If you do this, you will save many hours bending over your SFG and weeding.

Keith, no worries...the book describes the ideal setup...but if the ideal setup isn't a possibility, then you need to make whatever adjustments work for you in your garden.

I couldn't buy 5 different kinds of compost...they just weren't available, so I bought the 3 that I could find.

Venetian blinds to make squares are blindingly expensive...so I used clothesline.

Electrical conduit like the US folks buy to build their trellises simply doesn't exist on this side of the pond...so I used spiral trellises for my tomatoes...and they're 2m tall and threatening to take over the entire garden.

But you know what? I have a healthy, productive garden that I'm having great fun nurturing....so close is good enough for me, and I'll bet it will be work for you, too.

Don't forget that Mel recommends straight compost when they teach the technique in less affluent areas that can't afford peat or vermiculite or it's simply not available. He starts them off with amended native soil, then encourages them to use compost as they start making their own.

It certainly is a bonus to start with weed free mix, but certainly not a necessity as long as you use compost that is from many different sources (not just different companies, different types - homemade usually considered best since it is generally a blend of kitchen waste, yard trimmings, manures, garden waste from many different types of plants, etc. If you're making the best compost you can or buying the best you can and mixing, you should be in good shape. For my homemade, I also supplement my compost with lavasand, greensand, blood meal, bone meal, dried molasses, organic fertilizer (at least 3 different brands) all mixed into 2 different types of manure and almost all my flower and veggie garden waste/trimmings and kitchen waste.

I don't mind if there is a little soil mixed in (from scooping up the bottom of my heap when I turn it or when I'm using the last bottom bits). The biggest weed problem I've had so far is when I was too lazy and didn't get my basils trimmed before it went to seed.

Remember, I learned to SFG when it was the old, original book and Mel recommended amending the soil as much as you could. Yes, you'll have a few more weeds sprout, but if you check frequently, they're easy to pull as sprouts.

Thank you all for your very kind and considered replies.

I cannot tell you how supportive it has all been.

Right now, it's raining buckets and the wind is quite strong,
so while I've got my wood ready to shape into sfg beds,
I'm going to wait until the weather is dry enough to work in!

My plans are:

1 bed for unadulterated garden soil that has been sifted and graded by me.
1 bed for the same but with the garden dug over underneath to approx 12".

2 beds for my vermi-compost and compost mix
(because I think it will do better and I want to have some veg to give away)
2 beds the same but with the garden dug over underneath again to approx 12"
(because I think the deeper rooted veg will do better in this.)

1 bed - high rise - my vermi and compost mix - half with garden dug over to 12"
1 bed - high rise - unadulterated garden soil - half with garden dug over to 12"

Then I shall see what works best for me and then "upgrade" the beds to allow me
to grow the quantities of veg I need.

If my circumstances allow, I shall use the front garden for "pretty" flowers.
I was amazed to see how much my wife liked to have flowers around,
so I need/want to have something for her so that she "buys" into sfg as well.

As soon as the weather is dry I shall crack on and post the photos here.

Thanks for your help, guys - you've been a super bunch!

Many thanks
Kevin

I do not know what your limitations are financially, but adding some peat moss and vermiculite goes a long way to making the soil fluffy. You might want to experiment in one of the boxes. You will LOVE the feel of the soil.

without going into too much detail, I am disabled and get no state benefits
so cash is hard come by which is why I need to be careful with what I get.

This is why I have a pragmatic approach and if I find out my own soil gives
me a harvest of, say, better than 60% of MM, then I'm happy.

However, I appreciate and accept the difference that compost can make,
so I built a vermi-composter for all of £6 and it's working a treat!
By the time February comes around, I should have enough vermi-compost
to fill the beds I plan on doing.

Knowing how good emulsified fish waste is for gardening, I offered a fisherman
free wriggler worms in return for fish heads and tails and he looked at me like
I came from Mars! Lol!

How funny, I think I know that look , it was the same way they looked at me when I bought red wigglers at the bait shop ( oh ! the travesty) and the guys asked what was I going to catch and I said nothing, I wanted them for my worm composter and he rolled his eyes and gave me that look ! ha. sounds like you have access to some good stuff for your garden !

Haha! Sounded like a great trade to me.

That is why I asked about money. I am in what I call a low point myself and have had to make compromises, too. You are fortunate to have the worm waste. That should serve you well. I have one bed that is almost entirely homemade compost and I am pretty happy - and surprised with the results. I did have to pull out a few volunteers, but no problems with disease (my biggest worry).

Lol!

I've been at that low point for some years now.

During my "campaigning" (I am quite political!) I met a few other
families with disabilities and became friendly with them.

I strongly believe that while it costs more to live as a disabled person,
we still have the same bills, etc, to pay and so this leaves us with less
"spending money" for enjoyment. So out goes the theatre, gigs, beer
and pubs, etc. Growing veg allows some relief to the weekly bill and
allows a little flex for other things like a small holiday or the occasional
party.

I did get offered 200kg of apples this year but I had to turn it down as
I couldn't afford the containers to let it ferment into cider to give away.
Ah well, maybe next year! lol!