Kitchen Garden Forum

COMPOST TRIAL #1
COMPOST TRIAL #2
COMPOST TRIAL #3

I had intended, when all three trials were concluded, to post a poll to gauge opinion about the usefulness of these trials. But I cannot think of the most useful questions to ask.

Now that the first and third of the trials are concluded and the second one is well advanced, it would be interesting to read your reactions. Have the trials confirmed your experience/expectation; have they changed your views; have they given you any ideas about compost use etc, etc?

As no-one else has jumped in....
My interpretation of your experiments is that peat-free is not as good as peat-included, but not entirely impractical.
The questions we now need to answer are:
Are we prepared to accept slightly poorer results to conserve Peat Bogs?
Are the Peat Bogs really in danger?
If more people switch to peat-free, will manufacturers improve quality?
You may think I am someone who answers a question with a question.
Who knows ?

I think WestHamRon makes a good point. I don't think anyone said that the peat free composts were better, or as good as peat. I'm slightly surprised how poorly they did in some cases. The question is how much of a compromise are you willing to accept.

For myself, I reckon that I will not starve if my seeds emerge poorly. But I don't want to waste my time and seed. My compromise is really quite small amount of peat containing JI seed compost for sowing small or precious seeds, but Hew horizons for larger most robust seed, and NH or homemade for potting on. I'm experimenting with leafmould as a homemade alternative to peat, though I haven't done anything resembling a proper trial yet - maybe next spring ?

It would help if the formulation of peat free composts was more stable too - in our experience using a different bag of peat free compost can produce very different results. I would have also thought that they could somehow make the texture of the compost less fibrous.

I think maybe too many of us put up with rubbish - we have failures and just try again or think it's our fault instead of complaining. Maybe if we all write to the manufacturer when we have poor results they may make more effort to improve the quality and consistency of their product.

Some sensible replies, I use my own compost and seive to achieve fine compost for tiny seeds, it works for me. However I did write to defra and some suppliers regarding the poor quality of peat free. I do empathise with those struggling with the poor quality of peat free and who don't wish to destroy habitat, as Gallotments says

I think maybe too many of us put up with rubbish - we have failures and just try again or think it's our fault instead of complaining. Maybe if we all write to the manufacturer when we have poor results they may make more effort to improve the quality and consistency of their product.

.
very wise, if more people complain change can happen.

Although trial #2 is still ongoing, I have one decision made: I shall definitely not be risking my own compost again, given its lamentable performance.

You know, I find all this variability of germination a bit strange. I mean, seed want to grow. If you direct sow a lot of these things, just into garden soil, they usually emerge quite well. My garden soil has a lot of homemade compost in the top layer, and that doesn't seem too detrimental.

So why such poor germination in modules ? I wonder that it is not a lot to do with moisture and the management of it, which is tricker in containers, and the regimes needed for different composts might vary a great deal. Peat is kind of spongy and forgiving (unless you let it dry completely). Some of the peat free composts are quite woody and water drains through quite quickly - it is harder to maintain them as moist as opposed to wet or dry.

It also seems to me that most of these peat free blends have a lot of incompletely composted wood waste. I wonder that its continued decomposition does not deplete the nitrogen quite quickly, causing the check on the beans we se in some of the photos.

Finally, why do we not have specialist peat free seed composts ? The coarse multipurpose composts might be fine for potting on tomatoes etc, or (mistakenly) attempting to fill raised beds , where a lot of material is required, but the real good quality stuff for germinating fine seeds is only needed in relatively small quantities. That's my justification fo using the JI blend just for seeds.

My thoughts are that the manufacturers of most of the non-peat composts have got to go back to the drawing board so to speak.
Seeds will germinate as soon as initiated by moist conditions. What the seeds are sown in doesn't really come into the equation until the second stage, the production of adventitious roots that are to be the life blood of the plant and it is at this stage that how a plant will eventually behave.
It is patently clear that these plants sown in non-peat compost are failing at this second stage and that will effect the plant for the rest of its life. Whether the compost is too coarse and a lack of suitable fine soil or a lack of suitable nutrition is something we are not really equipped to research.
Like NB for my own seeds I have my own compost of pulverized straw and comfrey and I usually have been in the habit of adding a very small amount of peat because sometimes at times my own compost is on the moist side especially when starting a new batch generally because I have overdone the comfrey and not got quite the right mix. It takes some time for comfrey liquid to soak into straw and then compost.
As GLA says it seems that there is a great difference between bags of the supposed same non-peat compost.
I think that when peat goes the term Multipurpose Compost will be be a redundant term because all the producers appear to be using different ingredients so there can no general similarity between brands. There is at this present time because as I see them they are all rubbish!
If I do anything on a commercial stage I will continue to use Peat until commercial outlets will come under the effects of the ban.
(I probably will not be around then but I suppose that's one way of getting around the ban!)
JB.

By sowing in roottrainers in identical conditions I think that the problem I experienced comes down to 2 of the things that JB identified - lack of suitable conditions for root formation and/or lack of nutrient. I am now feeding the plants on the non-peat side to see if that makes a difference. I think it already has but really too early to say.

I am now going to separate out the non-peat Sprouting Broccoli and Kale into the same seed tray, keep feeding them and see how they develop. Will also take photos of the root development of peat and non-peat.

NB, Tony - everyone. Homemade compost is not the answer. Joe Public can't make their own. They need a reliable compost, peat or not. And in order to persuade producers to improve the non-peat the more facts we have the better. So please choose a couple of composts, sow in roottrainers and tell us the results. It really is very simple - if you can keep the slugs at bay!

Alan & Colin, this might be naive, bit did either of you measure the ph of.these composts at the point of sowing?

Peter - I didn't. Why should I? They were both ready-made multipurpose composts and treated as such.

Nor me. I was using composts "as found". In any case, I never measure the pH of anything.

Hi Alan,
The PH could actually play quite a considerable part in this but if the PH of Peat can be adjusted to make it usable, Multi Purpose, then surely it should be part and parcel of Multipurpose Peat-free of it being Multipurpose and having the correct PH. I read Multipurpose as not only covering several applications but also being fit for the job of multitasking
which is what Peat Multipurpose compost does.
From what I read in a previous thread the nutrition was coming from Sugar Cane Waste amongst other things imported (I wonder how much carbon is being expended to scource these?) which are new to these shores and are they available in a condition that new seedlings can take up?
JB.

Trying to identity why the poor results.

Improperly composted and sealed moist woody waste could continue to decompose which will: depleted all the nitrogen, lock up the iron and go acidic. Hence poor germination and onward growth.

Germination not poor. Think continued decomposition unlikely. More likely long term nutrients rather than short-term as JB suggested - but again it points to the need for standards.