Wednesday, 27 March 2013

Recycling: Green waste, and Food waste

Recently I managed to get an invite to go on a tour of my local council's food and green waste recycling facilities.

It was very interesting!

Obviously, compost is one of my specialist subjects, so I was interested to see how it would be done commercially, and if there were any tricks of the trade to be learnt.

The tour was of two different facilities: the first was mostly garden waste, with some food waste,  being composted in the "normal" fashion for use as agricultural soil conditioner/fertiliser, and the second was food waste only, being processed through an anaerobic digester to produce methane (converted into electricity) and organic liquid fertiliser.

First on the agenda: in-vessel composting.

This is where the contents of the Brown Bins (in my part of Oxfordshire, green garden waste goes into brown bins, whereas cardboard/glass/plastic recycling goes into green bins. Illogical, huh?) go, along with some of the food waste that we put out in corn starch bags.

The process is surprisingly simple, and very similar to that of normal composting, but on a rather larger scale, and it happens correspondingly faster.

The trucks arrive from Oxford City Council and Cherwell District Council, go over the weighbridge, reverse into the receiving hall, and tip their load out. The trucks then leave, being weighed again as they leave, so the company (Agrivert) can calculate how many tons of waste they are processing.

The load is put through a giant shredder/mixer, that orange thing, then moved out of the receiving hall into a series of long roofed tunnels to get up to heat.

They use what I would call a loader - like a tractor, but with a big metal bucket on the front to scrape up, move, and tip out the material.  They have three or four of them, and they do all the moving of materials on the site.

As you can see, there is hardly any mess or leftover bits around - the whole site, I have to say, was remarkably clean and well-kept. And not because they had visitors - the site was operational the whole time we were there, and we all had to wear high-vis jackets, and were warned to keep alert for moving vehicles at all times.

The second stage is the tunnels: not rounded poly-tunnels, but long rectangular pens, with flat roofs that open up on struts to allow the loaders to get in and work unimpeded.

Here we are, at the row of tunnels, and you can get a general idea of the scale of them from the small size of Brian, site supervisor, opening one of the doors further down the row for us.

You can also see the strut arrangements above the tunnels, which allow the roof panels to be opened.

The freshly mixed and chomped waste is loaded into the tunnel, the roof is closed, the doors are closed, and they are left to get up to heat.

To help this, air is blown in from underneath, to oxygenate the heaps, and excess liquid is drained off.

We all  know that compost heaps generate heat, and these ones do it on a rather larger scale - when the door was folded back, a fog of steam wafted out! Several of the tour members held their noses in somewhat cissy fashion, but there was no unpleasant smell at all, even though these heaps had only been stewing for a few days.

 Here's an unhelpful photo of the inside of one of the tunnels: just a heaving, steaming mass!

As you can see, not much rotting has taken place yet, you can clearly see the shapes of twigs etc, and the white stuff is just fungus, as you would expect in something warm and dark.

Of course, they don't have the usual brandlings or Tiger Worms in these piles  - it is far too hot for livestock. The rotting process is purely heat-driven, and all the heat is generated by the rotting action. Clever, huh? All they have to add is the oxygenation: air is free, and the fans are surprisingly low-powered, just 5 kilowatts per tunnel, and they only run when the sensors indicate that they are needed.

The tunnels have to achieve a certain temperature (60 degrees) for two days, and the tunnels are closely monitored to ensure that this happens. The material then stays in the tunnel for a surprisingly short time - 7-10 days - before the tunnel is opened, and the heaps were moved out from the other end into the next phase, the second set of tunnels.

The second set of tunnels were identical to the first, but only half as many of them: of course, as with domestic composting, the material reduces rapidly in volume.

After another fortnight in the second set of tunnels, the material is scraped out again by the loaders, or "loading shovels" as they call them, and stacked in long rows (referred to as "windrows" ) in the open yard, to continue the rotting process.

When they are "done", the material then gets loaded through an industrial sized sieve - ah, said our group, at last the expected conveyor!  The loaders tip the stuff into a hopper, it runs up a conveyor then through a rotating drum with a coarse 1" mesh.  The "fine" stuff - relatively fine, not what you and I would call compost, but this is agricultural material, not potting compost! - drops through, the rough stuff goes to the end, where air is blown up through it to get out the contamination, ie the plastic bags and other rubbish.

Deborah, our tour guide, told us about the ridiculous rubbish that people leave in their garden waste bins - not just the *sigh* expected plastic bags, and the occasional plant pot, but even huge things such as barbecue sets. Why, while we were there, we saw a wheel from a barbecue, any amount of plastic bags, and the arm of an office swivel chair.

Why? Why? Are people really that stupid? Apparently, "yes", to go by what we saw. Garden waste recycling is not like the council-run rubbish dump, with a dozen blokes stood around watching, able to shout "Oy!!" and fish out items that have been put in the wrong container. This is a commercial operation, and they can't afford to have people picking over the incoming waste. Anyone reading this and thinking "huh, well they jolly well ought to pay someone to pick out the rubbish, it shouldn't be allowed to get onto our fields, grumble grumble"  should realise that to do so, the cost of rubbish collection - currently "free" in amongst our council tax - will rise significantly. And no-one wants to pay directly for rubbish collection, do they?

So please, spread the word that we, the general public, should be a bit more careful about what we put in our garden waste bins.  As it is, the plant has one member of staff watching as each truck unloads, to check for contamination, but we can all do our bit to help.

Getting back to the process, the sifted material is then heaped up, ready to be collected by local farmers and spread on the land.  We ran our hands through it (well, those of us like me that don't mind getting our hands dirty) and agreed that it was quite coarse, but still good stuff. It had a lovely texture, just dry enough to be pleasant and light, moist enough to hold an impression when squeezed.

Which, incidentally, is my definition of Perfect Compost.

The finished product goes mostly to agriculture locally. Deborah told us that it goes to farmers within a tiny radius, less than 10 miles, which is wonderfully eco. They are even prepared to give some of  it away free, to allotment groups or charitable gardening groups, a comment which promoted a lot of interest amongst the group!

So, lessons learned from the day?

Firstly,  already known, Don't Contaminate Your GreenWaste Bin!!  Think about all the things that you would hate to find in your bag of multi-purpose compost, bought from a garden centre: glass, bits of plant pot and plastic bags, plant labels, stones, etc. Then don't put them in your garden waste bins. Spread the word.

Secondly, Size Matters.  On a small domestic scale, you need brandlings and time - 6 months to a year, to make good compost.  When done on this sort of scale, it can happen in mere weeks. But don't expect to achieve this timescale at home.

Thirdly, Simple Is Best.  This recycling plant is wonderfully efficient, with minimal handling of materials, minimal staff, no mess, clean concrete yards, no steps or ledges for material to catch on: they even used the excess soil left over from levelling the site to make a nice earthen/grassy bank around the site, to avoid offending the eyes of the occasional passing motorist.

Next time: anaerobic digesting - which is what happens to the things we put in our kitchen waste caddies: and then, part 3, what happens to our recycling wheelie bin waste!


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Friday, 8 March 2013

When is a lawn not a lawn?

Earlier this week, we actually had some sunshine,  and lo! and behold, out came the crocuses.



Crocus, plural, anyway:

How lovely, to see them all fully open, holding their little faces up to the sun.

At this time of year, the lawn stops being a lawn, and becomes an extension of the flower beds! Of course, in a few weeks' time it will look like nothing on earth, with straggly dead foliage, and scruffy over-long grass, but my client and I agree that it is well worth it, to have this spectacle at this time of year.

And on this particular day (Tuesday of this week) there was a hard frost first thing, and I went out to work in thermal long-johns, thermal tee, thermal gloves, thermal socks, and a scarf... by half past ten I was getting seriously over-warm, and had to go into the client's garage to strip off my thermal long-johns before I passed out from overheating.

Fingers crossed that they don't have cctv in the garage....

Thursday, 7 March 2013

A Death in the Trouser Family

Oh dear, look what happened yesterday:

I was energetically throwing stuff onto the bonfire pile, and one of the buddleia branches snagged my trousers on the way past.


Well, they are very old trousers - I haven't had a horse for 15 years, so they must be at least 20 years old, or more, and they were getting a bit thin and tatty.


I get so attached to my old clothes..

And here is the huge bonfire pile to which I was adding the buddleia:

Impressive, huh? And all my own work.  This lot represents how much uncompostable material is produced by a three-acre garden over one winter: you might just be able to see that it is now higher than the roof of the old summerhouse.  The client has promised me that they will have a go at burning it off soon...

Monday, 4 March 2013

Down comes the Western Red Cedar

Back in December I wrote about the preparations for having a large conifer removed at one of my gardens - by which I mean one of my clients' gardens, of course - and finally, last week, the planning permission was received and the Tree Surgeon arrived to do his work.

Here's the tree, to remind you:

...a whopping Western Red Cedar, with a split trunk.  

One whole day of roaring chainsaws and loud thumps later, there it was, gone.

Here's the state of play at the end of the day, when all but the largest pieces had been removed:

Impressive, huh? You can clearly see the split in the trunk. The lads ran out of time on the day - it was a very, very big tree - and left this lot behind, to be collected a day later.

The dustbin, in case you are wondering, was part of our Protect-the-Hydrangea plan: a plan which somewhat failed, as the tree men just dug it up and moved it safely out of the way.  Good thing too, it would have been completely flattened!

So, the moral of this story is that tree removal does tend to flatten the garden all around - not to mention the daffodil casualties all across the lawn. But it had to be done, and it's going to make a big difference to the whole garden, not just this area underneath it: my client commented that she looked at the shade it was casting,  in a rare sunny moment earlier in the week, and the shadow of this tree spread the whole way across the garden.

Once these bits are gone, we can clear the ground, dig it over, see if anything survived, then we can think about replanting.


Friday, 1 March 2013

Roses: pruning to a framework.

Climbing roses, those which are trained up fences, walls, or other structures, need pruning just as much as bush or standard ("lollipop") roses.

The usual advice is to cut out a third of the oldest stems each year.

Well, that's fine in principle, but have you ever tried to do it? When all the stems are firmly intertwined, usually thorny, and form an inpenetrable matrix?

My preference is to cut climbing roses back hard each year, to a framework of old wood, allowing new flower-bearing shoots to grow each year.  Not dissimilar to what we do on bush roses, really, but on a "long and thin" scale rather than an "open goblet" scale. This has the effect of keeping the rose within bounds - and generally speaking, forces the rose to produce flowers at a height where we can actually see, smell and appreciate them.

The fact that my business insurance does not cover me to go up ladders has nothing to do with this pruning regime, honest...

But what happens if you don't have a framework of old wood? What happens if you have a tangled mass of thorny stuff? Sometimes the only answer is to cut it all right back down to ankle height and start again.

First things first, when pruning climbing roses: you have to understand that roses (like a lot of climbers) think that they are still jungle plants. They strike out directly upwards, towards what they think is the rainforest canopy: then when they reach maximum height, they flower.

Usually, the trigger to flowering is when the stem can't go upwards any further, ie when it reaches the top of the canopy and starts growing sideways.

If you take a rose shoot and bend it gently over, as near to the horizontal as you can, it fools the rose into thinking that it has reached the canopy, so it will then  produce flowers.

This is the basis of all climbing rose pruning: try to get the stems going sideways.  If they are tied to arches or obelisks, try to get them wound around in a spiral, instead of zooming straight up. If you can instill this sort of discipline to your roses, you will make life easier for yourself for years to come.

And, of course, be brave about pruning: if you always cut them at eye height, they will always grow at least four feet before flowering. So if you want the flowers at eye height.... yes, you have to cut them four foot lower down. I know, I know, cruel and harsh, but that's what rose pruning is all about: as has been said,

"Ask your worst enemy to prune your roses for you."

Just imagine what a slaughter your worst enemy would do - then do exactly that. I've been following this maxim all my life, and it certainly works!

So, to sum up, when pruning old climbing roses, you have to be very brave, and really cut them back hard.

Typically, I have lots of "after" photos, and not a single "before" photo. Memo to self: must take "before" photos...

Here are some climbing roses in my care:

Firstly here's an old one that I have been rejuvenating over the last couple of years: it's in a pot, in a corner courtyard with trellis on both angles: and had developed into a monster plant, about 10' in height, with all the flowers way up there out of reach.

Two years ago,  I removed half of the thick old stems, right down to the pot: gave it lots of fresh compost, lots of water, and the next year it repayed me nicely by sending out some good new shoots. I forced these to curve over, and tied in as many of the next year's new shoots as I wanted, pruning off the rest.

Now you can see that my new framework is taking shape, moving the growth across as close to horizontal as possible, to spread the flowers out over all the trellis panels, instead of just one.

Here's a good example of One I Prepared Earlier: this used to be a wild mess of spiny shoots,  and I have been patiently tying in the best new shoots, and cutting out those going in the wrong direction.

You can see that the strongest shoot was on the right, but there is no room for it to spread any further, and it was too rigid to bend it over to the left. So I kept it on the right, and tied in all strong shoots heading leftwards, pruning out any that dared to try going right.

By doing this, I have managed to get the rose to grow in the direction that we want it: last summer the wall was absolutely covered in flowers, and looked fantastic: and now, through the winter months, we have a neat, organised, formal shape to look at, instead of a mad mess of tangle and thorn.

It's not quite perfect yet - there are a couple of low shoots on the left that aren't quite in line, because I am waiting to see which is going to be the strongest shoot. I will then remove the others.

And as for this next poor thing (below): well, don't be too sorry for it, it's a monster thug of a rose, which used to gallop up the fence every year, trailing great thorny lashes in all directions, with all the flowers hanging over the top of the fence for the neighbours to enjoy.  The stems were as thick as my wrist, and completely bare to a height of about four feet, despite my efforts every year to force it to flower lower down.

Definitely a case of You Have To Be Cruel To Be Kind.

At last my client saw sense: "Cut it right back!" he said, "I can't stand it pushing the fence over any more!"

Restraining the urge to whoop and  holler, I leapt for my pruning saw and cut the old, woody stems out right down to ground level, keeping the five strongest new shoots and arranging them fan-wise.

I  know it looks like nothing at the  moment, but trust me, I've done this dozens of times and I haven't killed a rose yet. *she said, touching wood*.

This will form the basis of my future framework for this rose:  these shoots will thicken up and set in place, and each year from now on I will trim back all new growth to these shoots.

After a radical pruning like this, I always give the roses a feed - a fistful of balanced food such as Gromore will do it, along with a dollop of home-made compost if at all possible. And a good slosh of water, even in the middle of winter.  Most of the modern commercial fertilisers are slow-release, and many of them are temperature sensitive, so the nutrients won't be released and wasted now: they'll be ready in a few weeks' time, when it warms up a little. But it's better (in my opinion) to add the fertiliser now, while I remember, rather than relying on a client to do it later.

So there you are, rose pruning to a framework - and if you don't have a framework, how to start one. 



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