Topic: Last year's compost

[gray1720]

While clearing out my parsnip and carrot pipes today. and looking at the full wheelbarrow of spent compost, I got to thinking about what the hell to do with it - I've always just added it to the garden, but what do other people do? At the rate I get veg back from it, I could buy a tin and a half of supermarket carrots - mind you, the allotment ones are always fangier than a vampire conference, and full of carrot fly.

Add in to that the tomato pots... I spand a mint on the stuff!

[Harry]

While clearing out my parsnip and carrot pipes today. and looking at the full wheelbarrow of spent compost, I got to thinking about what the hell to do with it - I've always just added it to the garden, but what do other people do? At the rate I get veg back from it, I could buy a tin and a half of supermarket carrots - mind you, the allotment ones are always fangier than a vampire conference, and full of carrot fly.

Add in to that the tomato pots... I spend a mint on the stuff!

IMHO..... I've asked this about seed compost. Personally, I'd re-use it till it conspicuously fails. Demand high return on investment from bought compost, Unless it is holding infection, it would be pretty insane to chuck away a £4 bag of compost after growing 50p of carrots in it.

It's only spent when you say it's spent. At the very least, add it to your compost heap, where other added 5h1t will recharge it.
 
Does it have the structure and water holding ability you need? If so, add chemical nutrients such as growmore, or use it as is, to start seedlings which don't need nutrients?

If it's weed free, use it as a barrier over some weeds?

Or how about sowing it with a green manure crop and let nature recharge it with nutrients?

If all else fails. I'll take it :) You won't catch me chucking away compost.
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But then I'm new to this and I'm tight as a ducks bum.

[Paulh]

I wouldn't use it for seeds or the first potting on of seedlings, as much of the nutrients will have been washed out and there would be pests and diseases. Why give less than the best you can to what you are eagerly nurturing this season?

I sometimes use it to mix in with (older / newer!) compost for the large pots in my garden which have bedding plants in each summer. Or to top dress pots which hold permanently things like a bay, olive, fuchsias.

Otherwise I use it as a soil improver on the allotment plot. I spread it or fork it in. It has a limited lifespan as a mulch because (i) it will have some amount of seeds in it anyway and (ii) it is a good growing medium for whatever blows into it.

For my spent tomato grow bags, it has been particularly successful at improving the area where I grow salads, carrots, beetroot, chard, etc from seed. The soil is clay-based but a generous addition of this stuff has really made a difference.

I wouldn't put it on the compost heap: it's not got anything much in it to rot down, even if it is a rootball,

[Tee Gee]

Strange how a few of us are getting around to this way of thinking about" Spent Compost"

I passed a few comments in March last year; https://www.allotments4all.co.uk/smf/index.php/topic,83251.msg837368.html#msg837368

As I mentioned then;  "since giving up my allotments I have been growing a bit more stuff in containers which you will appreciate requires a lot of compost, hence my plan to make my own"

I got to thinking that I grew my stuff in the same soil for over 30 years, why can't I use the spent compost I end up with after harvesting?

On the allotment, all I did was aerate (dig) the soil add humus and fertiliser and my stuff grew quite well.

So why not do similar with spent compost?

Like Gray:I need loads for my Tomato pots, and like Harry says, "It's only spent when you say it's spent".
 
He mentioned; "Does it have the structure and water holding ability you need? If so, add chemical nutrients such as growmore"

I find it does! Particularly when I add sieved well rotted horse manure to my spent compost, then add the required amount of John Innes Base mix fertiliser.

In terms of "seed compost" I am thinking of going back to the drawing board on that issue!

Yes it doesn't need nutrients, but I thought "sterility" was important, so I nuked by spent compost in an old microwave oven that I have.

On using it this year, I am finding that my seedlings are not developing as good a root system as I did when I used diluted MP compost.

I don't know if the" nuking" took something out of the compost that is essential to promoting root growth? I am having a similar problem with taking cuttings, that is, the cuttings are taking much longer to root, and the root system is quite poor.

By way of an experiment I have transplanted some cuttings & re-pricked out some seedlings this week, but before planting them on, I rinsed the roots in water to remove any nuked compost that was sticking to the roots.

My experiments with getting the correct pH, and a good humus rich compost without using Peat is coming along nicely in my opinion.

Today I made up 120 litres of Ji3 compost for around a fiver which works out at less than 5p per litre which compares favourably well with many of the MP composts selling at around 10-12p per litre! (I looked online to see what Ji3 is selling for, and it was around 45p per litre, so a massive saving there)

BTW this is a link to a video I made on the subject last year, perhaps I might get round to making another to show the changes I have made.https://1drv.ms/v/s!AsAAxsMk9ROykaVw4PekTG1WuICiIw?e=uZNaeF


....and that folks is my opinion on the subject.

PS. Just a quick question; Do you think that peat based composts will finally disappear next year? Or will it be, like many things that come out of Westminster, it will be delayed again?

[Harry]

On the allotment, all I did was aerate (dig) the soil add humus and fertiliser and my stuff grew quite well.

So why not do similar with spent compost?
 
He mentioned; "Does it have the structure and water holding ability you need? If so, add chemical nutrients such as growmore"

I find it does! Particularly when I add sieved well rotted horse manure to my spent compost, then add the required amount of John Innes Base mix fertiliser.

In terms of "seed compost" I am thinking of going back to the drawing board on that issue!

Yes it doesn't need nutrients, but I thought "sterility" was important, so I nuked by spent compost in an old microwave oven that I have.

Speaking of compost. Heads up...

Morrisons have two packs of Dehydrated Coir compost 'bricks' for £14. ( or £9 per pack ) Each pack makes 90L of soft, fluffy, compost. Amazingly easy to carry home. It's totally free of nutrients, so effectively a hydroponic growing medium. If you're not familiar with it, check it out as a novel product.

I'm experimenting at starting my seeds in that. Last year, i grew a decent tub of spuds in only coir compost and added tomorite. So it does work.

Wilkinsons online, and poundstretcher sometimes have it.

[gray1720]

Somehow I've managed to lose my reply twice so I'm going to say "Bucket!" and try again another day.

[Harry]

Oh 'Bucket' :) I know what you mean.
Yes. some of my best crops were grown in buckets of a mix of coir compost and topsoil. Amsterdam forcing carrots and peas, especially. Far easier to control weeds and moisture than having them straight in the ground. Ultimate no-dig.

[gray1720]

Too busy fitting allotmenteering round the rain to drop by until now...

With the thoughts above in mind, I'm going to experiment with adding organic matter and fertilising as needed to try to get the stuff to go further - the carrot pipes and the tattie sacks take so bloomin' much!