What is the best compost to buy for 2012?

[Geoff]

I have just about stopped assuming there is any food in bought in potting compost, it seems the simplest approach to me.
When I make my own compost from soil, leaf mould and sharp sand I am usually looking for something similar to John Innes No. 2. To add fertiliser to my mixture according to the JI formulation I would have to add 2.4 Kg Hoof and Horn, 2.4 Kg Superphosphate, 1.2 Kg Potash (i.e. 6 Kg JI Base) and 0.6 Kg Lime to a cubic metre of mix. I don't mix a cubic metre at a time and I don't use these individual ingredients. JI Base has an NPK content of approximately 5.2:7.7:10. Readily available Fish, Blood and Bone (FBB) is approximately 5:5:6.5 so it is not too different. Twenty 5" pots hold approximately 25 litres so require 150 gm JI Base and 15 gm of Lime so these are easier figures for adding fertiliser.
So what do I do in practice? Usually measure out ten 5" pots of compost and add 75 gm of FBB (I've drawn a line on a scoop). If I'm using it for Brassicas I add the Lime but otherwise don't bother. If I'm in a fussy mood, for Brassicas I might add extra Phosphate and for Tomatoes, Peppers or Aubergines I might add a bit extra Potash.
Going back to my first sentence, if I am using bought in compost I add the same amount of FBB etc. to be sure there is sufficient food to keep things going for a while. Could be more scientific but it seems to work.

[Ricard with an H]

Thank-goodness for this forum, even though the help was too late to stop me loosing quite a few plants to this new Horizon product at least I know it isn't all about me being a plonker.

I was suspicious of that woody material so my first seedlings went into 50% peat and the rest of the New Horizon. They did Ok, everything I planted into 100% New Horizon sulked or failed.

I'm now mixing it with soil just to get-rid, in the words of vernacular, "We've been done".

I still have lot's of plants in 100% New Horizon, it'll all have to go into the ground as soon as possible.

Two packets of french bean seeds have gone and withered into this stuff, if I'd been more experienced I would have been able to resurrect the situation.

No beans this year, what a shame, I'm gutted.

[alan refail]

Hi Richard

New Horizon - think Brave New World. It's just a marketing ploy to get you to buy other people's refuse. On a more positive note, sow French beans now in decent compost and you'll have a satisfying late crop.

[Ricard with an H]

On a more positive note, sow French beans now in decent compost and you'll have a satisfying late crop.

Oh ? It's not too-late for seed ?
I feel sorry for the local garden-centre who bought the stuff to sell, in-good-faith because the bags have a 'Which' recommendation. And people who bought it that must be wondering what is happening to all the work they put into creating plants.

[alan refail]

Oh ? It's not too-late for seed ?

No

[peter]

My first sowing were planted out last week, the second will go out next week, when the third will get sown.

[Ricard with an H]

Fantastic and thank-you, and there I am getting all-depressed about my failure.

Just sliding to one side slightly, I've just been down the lane to see how the barley is doing, it's oil-seed rape this year, not barley.

I'm concerned about my poor looking stony-soil but the farmers are growing stuff in soil that is marginally worse than mine. Presumably the whole success of each crop is down to carpet-glyphosate-ing, deep ploughing and heavy nutrient.

I'm not actually digressing, poor soil with the correct attention produces an annual crop. This New Horizon stuff doesn't even sustain life if you feed it nutrients.

Thanks to you-lot, I'm sorted. Just need to cope with the west-coast weather now.

[Tony Hague]

I'm not actually digressing, poor soil with the correct attention produces an annual crop. This New Horizon stuff doesn't even sustain life if you feed it nutrients.

I know I have commented that New Horizons is not what it used to be, and that it is variable bag to bag, but - I really don't believe it is so bad as some of you suggest. I have used it successfully for a good few years when the homemade mixes run out. Now, maybe I have lower standards because I have never used peat based multipurpose. Maybe, because I use my own leafmold based compost for the really delicate stuff, I avoid the worst of it. But I find that I usually get emergence in line with the seed standards - say 80%, for the seeds that are large enough to sow singly.

I strongly suspect that for people accustomed to peat, it is the difference in watering needs that causes a lot of the failure. Peat is like a sponge, relatively easy to keep moist, but these wood waste based composts are difficult to keep just moist - too much water and it runs off (taking the nutrients with it), but the loose and lumpy texture means that the hydraulic coupling is poor so the surface can dry out quickly despite the compost below being quite wet.

So, I reckon that you need to water little and often, keep shallow sown seed in a propagator, or cover the seed with fine vermiculite instead of the compost, and maybe use just a little of "the good stuff" for very fine seeds.

As for peat free composts being a way of selling you someone else's waste ... isn't this common and a good thing ? After all, we don't raise animals just to produce manure, hoof and horn, dried blood and bonemeal. They are all somebody else's waste. In fact, re-cycling waste is what composting is all about to me.

[alan refail]

As for peat free composts being a way of selling you someone else's waste ... isn't this common and a good thing ? After all, we don't raise animals just to produce manure, hoof and horn, dried blood and bonemeal. They are all somebody else's waste. In fact, re-cycling waste is what composting is all about to me.

Point taken and understood, Tony. The trouble is that you don't know whose waste, nor, more significantly, what the waste actually is. Therein, I think, lies the problem.

[Tony Hague]

I do share a bit of that concern. It is visually apparent that New horizons has shredded waste from fitted kitchens in it. I'm sure that treated timber must find its way into some the composts, because no matter what size notice there is on the wood waste skip at the tip saying "no treated timber" there's always some in there. Similarly wood with leaded paint. I wonder how well it is tested for heavy metals etc.

[vegpatchmum]

Hi Richard

Sorry to hear of your troubles. Definitely get more French Beans on the go and Runners as well if you like them. As for the rest of your plants, were I you, I'd repot them into fresh compost first to give them chance to recover and take as many nutrients as they can get before putting them into the soil, especially if you are concerned about the type of soil they're going into.

Earlier this year I had much the same sort of problem with my tomatoes, peppers, chillis etc, which I had potted on into a bag of compost I had left over from last year . The bag hadn't been opened but it had been outside all Winter. My seedlings were definitely sulking and so I sowed a fresh batch just incase, and OH popped to the garden centre and came back with a pick up bed loaded with bags of compost.

It took me a few hours but I potted each and every seedling into new compost, after first carefully removing as much of the old compost as possible without damaging the root ball, crossed my fingers and hoped for the best. 1 week later there was a noticeable improvement and now all the repotted seedlings are healthy plants either in the greenhouse, growbags or beds

Take heart - all is not lost.

VPM
x

[Colin Miles]

I strongly suspect that for people accustomed to peat, it is the difference in watering needs that causes a lot of the failure. Peat is like a sponge, relatively easy to keep moist,

Tony - this is, unfortunately, another reason why these composts currently aren't suitable for the amateur. And watering anything in pots/containers is not easy no matter compost you use or how experienced you are.

[Ricard with an H]

I really don't believe it is so bad as some of you suggest. I have used it successfully for a good few years when the homemade mixes run out. .

Thats interesting Tony, and just to remind you that my first batch of seeds and potting-on were in 50/50 NH and clover. They were all fine, I've used six bags of the New Horizon but only three bags were used mixed with peat.

I just went to the local garden-centre that sold me the NH, I wasn't making a complaint, just shared my experience. I'm the only customer who has voiced a problem and they've almost sold the whole order that they took in as stock. They did say that they were nervous about selling the NH and appreciated my feedback.

I think I've been over-watering the NH in some cases, I noticed that whilst the first half-inch of the top was dry the majority was still very moist.

Tony, I was determined to use the NH and happy to accept my novice-ness as the culprit but I'm not risking any more wasted labour on it.

Sorry to hear of your troubles. Definitely get more French Beans on the go and Runners as well if you like them.

Just bought myself a bag-full of bean seeds and they're going in today so thanks very much for the encouragement, the slugs have all but finished my courgette plants and a fair-few broccolli. I'm home-alone until Saturday so only you-lot to moan to.

Thanks for sharing, there is some positive though, although the carrots are bendy I have carrots and lots of fennel/dill, masses of lettuce and some Kohlrabi. Some sage and other stuff that I didn't lable and isn't big enough to identify.

Better get of this machine and get re-potting.

[alan refail]

Hi Richard

Sow some more courgettes. I shall put some more in at the end of next week. They always give a quick(ish) crop from a late sowing.

[John Walker]

I know I have commented that New Horizons is not what it used to be, and that it is variable bag to bag, but - I really don't believe it is so bad as some of you suggest. I have used it successfully for a good few years when the homemade mixes run out. Now, maybe I have lower standards because I have never used peat based multipurpose. Maybe, because I use my own leafmold based compost for the really delicate stuff, I avoid the worst of it. But I find that I usually get emergence in line with the seed standards - say 80%, for the seeds that are large enough to sow singly.

I strongly suspect that for people accustomed to peat, it is the difference in watering needs that causes a lot of the failure. Peat is like a sponge, relatively easy to keep moist, but these wood waste based composts are difficult to keep just moist - too much water and it runs off (taking the nutrients with it), but the loose and lumpy texture means that the hydraulic coupling is poor so the surface can dry out quickly despite the compost below being quite wet.

So, I reckon that you need to water little and often, keep shallow sown seed in a propagator, or cover the seed with fine vermiculite instead of the compost, and maybe use just a little of "the good stuff" for very fine seeds.

As for peat free composts being a way of selling you someone else's waste ... isn't this common and a good thing ? After all, we don't raise animals just to produce manure, hoof and horn, dried blood and bonemeal. They are all somebody else's waste. In fact, re-cycling waste is what composting is all about to me.

I couldn't have put it better myself. You do need to get used to and become familiar with the reliable and top-performing peat-free composts. Rejecting them because they don't perform exactly like a peat-based mix is rather like taking a new car back to the garage because all the knobs and buttons are not exactly in the same place, even though it runs fine (or even better than your previous car). That's, surely, what gardening's all about - learning and experimenting, over time, which brings experience. It's also about making the wisest use of precious natural resources.

This has been a very difficult and atypical spring/early summer for many of us, which doesn't help when we're trying out a new compost, but - trust me - none of the quality peat-frees are hard to use. Anyone suggesting they are no good for gardening either hasn't tried them, or is being deliberately misleading.

I feel I must put in a good word for New Horizon Peat Free Multipurpose (NH). The comments left earlier inspired me to go out and assemble a cast of plants, all of which I'm growing successfully in NH (see below). I don't think anyone is claiming there isn't a little variability between a few bags here and there, but it certainly doesn't warrant all the doom-mongering.

NH was one of the consistent top performers in my peat-free trials in 2011 (http://tinyurl.com/6m5rphe), and it's still a good doer this year (if you missed them, two articles based on my trials were published in the May 2012 issue of KG (a user's guide), pages 75-78, and June 2012 issue (a buyer's guide), pages 69-71). It's also an economical peat-free, often available on three-for-two offers, and is pretty widely available.

I agree that the chunkiness of NH can be frustrating, but there's always a sieve on hand, or you can use NH Seed and Cutting Compost, which is more finely graded. Personally, the damage to peatlands internationally, through peat mining, more than adequately cancels out any qualms I have about finding a few odd bits in any brand of peat-free compost. I have over 30 different brands in my trials this year and the 'bits' problem is almost non-existent.

For the eagle-eyed, the picture shows (clockwise from top left):

Pak choi Colour and Crunch (salad leaves)
Rocket (salad leaves)
Strawberry (overwintered in pots for early fruits)
Swiss chard Fantasy (salad leaves)
Petunia (grown from a plug plant)
Tomato Moneymaker (seedlings)
Pumpkin Mammoth
Tomato Maskotka (seedlings)
Pumpkin Jack O' Lantern
Courgette De Nice De Fruit Ronde
Pumpkin Jack O' Lantern
Courgette All Green Bush

These have all been grown in the NH as it came out of the bag and I haven't fed any of these plants. The courgettes/pumpkins are late sowings due to earlier failures due to poor germination. The tomatoes are being grown for use in my ongoing trials (which is where the petunia popped up from).