Compost Crisis?

There's been some concern in the media over the past couple of days about the risks of contracting Legionnaire's disease from growing media (aka compost) bought from garden centres. This isn't new (I saw it first reported in 2008) or proven, but it's re-emerged recently owing to a report published last week in Eurosurveillance. It summarises three cases reported in Scotland in 2008/9 where inhaling the Legionella bacterium via water droplets from wet compost is thought to have been the cause.

Three cases in a couple of years suggests the risk for any of us catching the disease from our compost is extremely low. The most common way people catch it is via the air conditioning or water system in a major building such as an office or hospital. Note it's not contagious as it's transmitted via the inhalation of contaminated water droplets. However, if anyone's still concerned, you might like to have a look here on the NHS website.

What concerns me more is the presence of glass in my compost. I bought 5 bags last year to supplement my home made stuff and two of them contained glass. The picture shows the piece I found last October whilst planting up my winter pots: the coin alongside is a 5 pence piece. The one I found earlier in the year was about 3x larger. I garden without gloves as much as possible as I hate not being able to feel the soil, so luckily I saw this piece before it found me.

I believe the move towards reducing peat in our compost is the root cause of this problem. Don't get me wrong, I'm not an advocate of peat. Despite the drawbacks of using peat-free compost I've found and commented about (as Veep) recently, I still use it wherever I can because I think it's the right thing to do. I'm sure the use of composted green waste in most peat-free or reduced peat formulas is to blame. It seems not everyone is exacting about what goes where in their waste bins and it looks like the screening process of composted green waste isn't yet able to achieve a 100% glass (or indeed plastic) free material.

What's your experience - have you found glass or other non-compostable materials in your bags? Is there anything else which worries you about going peat-free, or have you found the perfect product to tell us about?

Comments

  1. Sylvia (England)5 March 2010 at 09:31

    I am also concerned about the quality of multi-purpose composts. Though I haven't found glass, plenty of other bits. Last year I decided to buy seed compost to start seeds in and found it contained weed seeds - I was not happy. Also ashamed that I never got around to complaining to the company. Not sure what to use for seeds this year! Back to multi-purpose or find a different brand of seed compost. I read B&Q's is the best but that means a special journey.

    Best wishes Sylvia

    ReplyDelete
  2. Dave5 March 2010 at 09:35

    I had the very same problem last year when I bought a quantity of farmyard manure from a large DIY chain. The bags had a lovely picture of a cow on the front and claimed to be manure but when I opened and started using them I realised that the majority of the contents were actually shredded timber (not bark) with very very little manure. As I worked through the bags spreading them around my recently planted hedge I started to notice all sorts of contaminants, glass, plastic and most annoying to me laminate from old chipboard. It was only after it rained for the first time that I realised quite how many small chips of white laminate were now spread all around the garden. I wrote to the supplier complaining and they replied stating that as it was a localy sourced product they could not control the content. I don't agree with this as it is a mass produced product shipped to many of the stores. Sorry for hijacking, but this annoyed me at the time and you just brought it all back ;o)

    ReplyDelete
  3. Nick5 March 2010 at 09:55

    Difficult to imagine the legionnaire risk being very significant - you'd presumably have to be in close contact with pretty wet compost in a very warm environment before significant quantities of water vapour could get near your nose!?

    As far as contamination of compost with foreign objects is concerned, there have certainly been issues in the past - we've heard of plastic plant labels, lolly sticks, and bits of polythene being found in brand leader multipurpose composts - all originating from municipal recyclings presumably.
    Our local green waste collections are routinely spread on farmers fields rather than being routed back to consumers for this very reason I understand.

    ReplyDelete
  4. Susan Tomlinson5 March 2010 at 12:26

    Gee, I hadn't heard about the Legionnaire's/compost connection. Maybe we're simply too dry here in the SW US. Anyway, as to finding glass, etc. I don't usually buy commercial compost, so I couldn't say. I did buy a couple of bags of composted chicken manure last year to boost the veggie garden, but it came from a local source that is pretty trustworthy. And oh my, it was pretty stuff...

    I do worry about mice in my compost bin and droppings they might leave behind...

    ReplyDelete
  5. Anonymous5 March 2010 at 12:52

    Yes, we have found glass around the garden, and can guess it may have come from the bags of stuff we buy. We have been spending more to get the better quality bags lately, and that has helped. I kept wondering if someone wasn't throwing broken glass over the fence! As for the Legionnaire's, we stayed in the hotel in Philadelphia right after that was discovered in the a/c unit and the whole thing quarantined and cleaned, back in 1977. It was a very fancy old hotel, that had been hosting an American Legion convention when people began falling ill, hence the name of the disease. We stayed there for a pittance, and went to the Philadelphia Flower Show with the family. They, the family, were all allergic to the flowers and we had to leave immediately, but that is another story. I would say the glass is a greater concern. Wear gloves. :-)
    Frances

    ReplyDelete
  6. Juliet5 March 2010 at 14:25

    I use fertile fibre, which is peat-free, organic, and multi-purpose - but unfortunately also incredibly expensive. I've tried to find something cheaper in garden centres, but it's always been such awful stuff (not noticed anything like glass, just the fact that it was heavy clumpy wet stuff and most of the things I planted in it died) that I've gone back to the fertile fibre. I managed to get a reasonable peat-free veg compost for my tomatoes last year though .... but can I remember which one it was? No, I can't (doh).

    I should have thought, gardening without gloves, you'd be rather more at risk of tetanus than legionnaire's disease - and much more at risk of sticking your hand in some cat poo :/

    ReplyDelete
  7. Carrie5 March 2010 at 14:38

    Oh golly, the worst we gotten (from the council compost) is a few bits of plastic and a whole chicken egg (with dead foetus inside, we later discovered). I haven't found anything in the bags we have bought - yet, but now I shall be eagle eyed.
    Living in Ireland we have grown up with peat just being used without thought but we do now actively buy peat-free composts etc. I think adding good old cow poo or seaweed makes up for it.

    ReplyDelete
  8. Joan5 March 2010 at 16:06

    Thankfully, I've never found any foreign debris in our 'city waste turned compost', it's always good crumbly stuff which I buy when what I make isn't enough. Our region has one really good company that is organic and very clean. I very much dislike peat products because they dry out too much, too quickly, so going peat free won't be too hard for me. I've been testing coir products this year which I see more and more on the market. It seems to be a viable alternative.

    ReplyDelete
  9. Mr. McGregor's Daughter5 March 2010 at 17:47

    I've heard of the Legionnaire's connection, but it seems like a bit of a panic, as it must be difficult to inhale droplets of water from potting soil. (I know some people love the smell of soil, but really.) Junk in bags of compost is a big concern. I don't buy much compost, but last year I did to build up a raised bed & found bits of plastic. Yuck.

    ReplyDelete
  10. Damo6 March 2010 at 20:43

    Found all sorts of bits and pieces in the compost I've bought in although no glass thankfully. Only way to do it is make your own, or if your near an agricultural college they may have some for sale that has been made by their horticultural students.

    ReplyDelete
  11. VP7 March 2010 at 10:20

    Sylvia - I'm really annoyed by the amount of twigs and bits of plank of wood I have to weedle out before I can use the stuff. It's not a like for like replacement at all!

    Dave - it sounds like they were conning you. I'm sure there are standards for the bagged stuff. There certainly is for green composted waste: if it's sold for domestic use it should be 100% contaminant free.

    Nick - welcome and quite right: the risk of Legionnaire's disease from compost is tiny. You're also right re your observations on contaminants in compost. If it's not 100% contaminant free then DEFRA say it's for agricultural use only.

    Susan - I think you're OK with your mice droppings as long as you let your compost 'cook' for a while...

    Frances - you can always be relied upon to come up with a good story to add to the conversation :) As for wearing gloves, I really hate the feel of them on my hands, but I suspect I might have too if this contamination continues

    Juliet - thanks for the recommendation. I wonder if the cheaper stuff works out just as expensive when you factor in how much of the product can't be used straight away? I can feel the need for a little bit of research coming on...

    Carrie - I'd love to have access to some seaweed, but sadly we're too far away here.

    Joan - one of our local nureseries use coir but it's not so available in the shops here. I went to a talk about growing media last year - coir's very good at retaining water apparently.

    MMD - yes it's a bit of a panic and appears to be one resurfacing here from a panic a couple of years ago. It seems this debris in compost's a universal issue, not just here in the UK judging by yours and others' comments :(

    Damo - welcome! I have 10 compost bins of various sizes and still don't have enough! Besides the home made stuff is no good for seed sowing because there's the risk of damping off

    ReplyDelete
  12. Geoff7 March 2010 at 16:10

    VP
    Well done on raising the issue about Legionnaire's Disease and compost. From what I've read, there is no direct evidence that it was the compost that was to blame. Most instances of LD come from shower heads and a/c units in offices. So did these people have a shower or go to work that day?!?
    The compost in question contained green waste and, like you, I have concerns over using green waste from the Council in my garden - one reason being the chance of finding glass and other 'nasties' in it. The other being the introduction of pernicious weeds. I know that the green waste used in bags of commercial compost doesn't come from the same sources as the stuff we can buy. Personally, I love peat composts and probably always will.
    Geoff

    ReplyDelete
  13. Karen - An Artist's Garden7 March 2010 at 18:02

    I was overjoyed when our local council introduced the green bins for garden waste, and I looked forward to the day when I could buy "green manure" back from the council. However I wouldn't get any now if they paid me. One of my concerns is about pernicious weeds that may be in the compost. I have seen folk put Giant hogweed flowers/seedheads, bindweed and Japanese knotweed in their bins, even though the council has requested that these are not put in the weely bins.

    I have also found a load of dog poo in my own bin when it was parked quite near the road but still in our drive.

    And please don't get me started on what I am finding in bought in compost. Even the seed and cuttings compost seems to have large chunks of contaminates in it. How? Why?

    It makes me very sad.

    Great post VP, thank you

    ReplyDelete
  14. Anonymous7 March 2010 at 18:27

    I agree, the quality of compost has fallen dramitically. The peat free ones are full of flies and weed seeds and the reduced peat ones have god knows what in them. I too find glass and plastics. I wonder what else is in there? I think that legionaires may be the least of our problems.
    I completely agree with the move away from peat, we must preserve what is left of this specialist habitat, but when is someone going to come up a vialble alternative?

    ReplyDelete
  15. SS7 March 2010 at 18:48

    I don't know where the fault lies but have on numerous occasions seen, at my local municipal "dump", non-compostable material being tipped into the "green" skip. Ok, screening should filter out most of this but some plastic, glass, builders rubble will inevitably be missed and end up in the "compost" we buy. So perhaps if we were all a little more thoughtful the problem would be lessened.

    ReplyDelete
  16. Janet/Plantaliscious10 March 2010 at 13:19

    Not found much rubbish in my compost so far, but have run foul of cheap peat-free composts. Now use New Horizon organic peat free grow bags - I sieve it and mix in some sand for seed sowing (actually, I didn't even do that last year and it worked fine). Also great for potting on and containers, which is just as well as I managed to create a shade garden before discovering I wanted to grow veg, so have to use pots on the patio for edibles...

    ReplyDelete
  17. VP22 March 2010 at 09:32

    Thanks everyone for adding further comments.

    Geoff - I see you've added your say about peat over at yours. We'll have to agree to disagree on that one.

    Karen - you've reminded me I meant to ask whether anyone had seen a change in John Innes composts. I'm sure the bag I purchased last year was nothing like the correct formulation.

    Janet - welcome to Veg Plotting!

    ReplyDelete

New comments are not allowed.

Your essential reads

That blue flower: A spring spotter's guide

Image
Spring is a prime time for blue flowers and my daily walks currently have several from the same plant family* lining the local footpaths. As I walked past the Donkey Field the other day, I overheard some children ask their parents** what the pictured blue flower was. It reminded me it's often mistaken for those other familial blues and this time was no different, as they said it was forget-me-not, instead of the green alkanet it actually is. As well as similar flowers, most of these plants are hairy in their nature, flower around the same time, and favour damp, shady places. Many of them are great for pollinators too, especially bees and this week's warm weather has certainly drawn them to these flowers. This makes it even more likely for these plants to be mistaken for each other and it's a great opportunity for me to put together a spotter's guide in case you find the same flowers on your outings. Staying with green alkanet, the key features which set it ...
Read more

Jack Go To Bed At Noon

Image
Last year this rather exotic looking flower appeared on mine and several other allotments for the first time. Having been stumped (again) by Mr Allotment Warden as to its identity, I rushed home to find out what it was. It's salsify, aka the marvellous Jack Go To Bed At Noon - named as such because its flowers always close by midday. Here you can see both open and closed flowers - making it seem even more exotic and alien than in the first picture. I think this must be the cultivated version because the flower in my Francis Rose Wild Flower Key looks exactly the same in form, but is bright yellow in colour and called meadow salsify . Its other common name is Goatsbeard, which must be a nod to the fantastic dandelion-like clock which forms the seed head. With 'parachutes' like those shown above, who knows how far our plotted plants came from. I rather like the photographic dissection of the seedhead found in this link . Salsify is edible: its lateral shoots and fl...
Read more

Red Nose Day - Gardening Jokes Anyone?

Image
The nation goes ever so slightly bonkers on Red Nose Day - hurrah! Previously, it's been very easy to join in - usually via a dress down day at work plus lots of people up to mad things at the station and in the office. Everyone smiling for once - it's a real feel good day and all in a good cause. This year's different - every day's a dress down day for me now - my friend L suggested yesterday that perhaps I could have a dress up day instead and whilst that's a good idea, I confess that ballgowns and tiaras don't really feature in my wardrobe: scruffy student's always been my favourite look. So my Red Nose Day contribution for this year is to compile a list of gardening related jokes. For each one (clean ones only please) you leave in the comments below, I'll make a donation of 50p to the cause. Here's a few for starters just to get you warmed up: Q Why do potatoes make good detectives? A Because they keep their eyes peeled. Q What did the grape...
Read more

Salad Days: Mastering Lettuce

Image
I've decided one of my salad challenges for this year is to grow as many lettuce varieties as I can, ready for the publication of my planned Factsheet* later on. The idea is to grow as many of the Tried and Trusted lettuce varieties last year's Salad Challengers helped compile, then provide a visual guide and as many lettuce facts as I can muster. So far I've found around half of those listed**. Then naturally whilst I was out searching - because such is the way with seeds - a number of other varieties found their way home too ;) A couple of weeks ago I sowed 22 varieties***. Just the simple act of sowing them has me intrigued. Why are some lettuce seeds black and others white****? They split into about half white to half black in my sample and as far as I can tell it's nothing to do with whether they're a type of cos, iceberg, or whatever. I sowed them indoors and popped them into a propagator on the windowsill. The soil's too cold outside for sowing ...
Read more

VPs VIPs: Derry Watkins of Special Plants

Image
Last week I had the pleasure of visiting Derry Watkins at her home, garden and nursery - the acclaimed Special Plants - just a few miles along the road from me. I first met Derry at one of her open garden days last year and was keen to find out more about her wonderful garden and running an independent nursery. She specialises in tender perennials and regularly goes on plant hunting trips to find new treasures, particularly in South Africa. As well as running Special Plants and opening her garden under the NGS scheme , Derry holds day courses at her nursery, hosts Special Tuesdays from April until September, lectures and has written a couple of books. How did you find your way from Connecticut to the UK? I'd started a biodynamic vegetable garden in Connecticut and we used to have people come along at weekends to help out. A particular young man turned up: he returned many times and at the end of the summer I married him. So it was all down to love? Isn't that the...
Read more

#mygardenrightnow: heading into summer with the Chelsea Fringe

Image
Ahhhhhh, that's better! I love walking through dewy grass in bare feet, not that there's much in the way of grass on my back lawn this weekend. My wild and woolly lawn has morphed into meadow of sorts this month, which even NAH admits looks attractive*. It's also proved a great source for my Flowers for mum project so far, yielding self-sown perennial cornflowers, lamb's ears, and lemon balm in addition to the blooms you can see. These originated from elsewhere in the garden, the ox-eye daisies must have blown in from the A350 nearby. * = he got very stroppy about the weeds aka self-sown foxgloves in the lawn one year, so he's come along a bit since then. Skimble's demanding to say hello to you too. He does enjoy the patio when it warms up. If the embedded video doesn't work try this link instead. The Nectaroscordum are a revelation. I planted the bulbs around 2 years ago, but it's only this year they've bloomed properly. The bee...
Read more

Make Use of Mildew

Image
On my garden patrol this morning I spotted some powdery mildew on a couple of my new Verbena bonariensis plants. I suppose it was almost inevitable as I prefer to grow my plants hard - this means no water for them unless they look absolutely desperate. This approach means plants root themselves more deeply and have a better chance of survival during spells of dry weather like we've had lately. However, it also means I run the risk of problems like today's, especially with any garden newbies planted late in the season. We've had a good drop of rain overnight, so this should help my plants survive. I'll mulch them later today to help lock in the moisture as it's water stress which encourages the mildew to take hold. I've also removed the infected leaves and sprayed the rest with a milky drink.* I'm also pleased to find there's a use for my infected leaves. Oliver Ellingham at Reading University has started a PhD - sponsored by the RHS - researchi...
Read more

The Resilient Garden

Image
  Part of Tom Massey's Resilient Garden at RHS Hampton Court I've been pondering VP Gardens a lot lately. Last year's drought conditions set me off initially, then our harsher than usual winter combined with this summer's flip and flop weather means the thinking continues. It's a huge topic which I freely admit I'm struggling to get my head around. Tom Massey's Resilient Garden  at Hampton Court recently  tackled this topic brilliantly and was a timely interlude which gave me much food for thought. There he encapsulated the detailed research he'd found which informed both his show garden and book of the same name. I think it's one of the most important show gardens I've ever seen. It's clear the way I garden needs to change so that I have my own resilient garden. I haven't worked out the exact details yet, but Tom's book plus a couple of others (see below), alongside the rainwater management handout from the show garden's  sponso...
Read more

Chelsea Fringe 2014: Shows of Hands - Episode I

Image
The gloves NAH used to build the raised bed . The effects are L to R, top to bottom:  Original photo, Warhol, HDR, Green tint, B&W, Posterize, Boost, Cross process and Sepia Welcome to Shows of Hands - my Chelsea Fringe project for 2014! As you can see I've been having a bit of a play around in Pic Monkey for my first contribution. You're welcome to join in between now and 8th June 2014. The idea behind this year's project is to highlight the tool most precious to a gardener: their hands. How do I take part? It's simple. All you need to do is take a photo of hand(s) in a gardening context and then share it via your blog or other social media (such as Twitter or Facebook), then make sure I know you've done so. I've set up Mr Linky below for your blog contributions. The Chelsea Fringe photo on the right sidebar links to this post, so you can easily find it again when you're ready to add your contribution. If you share your photo on Twitter, ...
Read more

Testing Times: Tomatoes

Image
  I've run a couple of tomato trials this year. The first is a revisit of the biochar trial with Oxford University I attempted some years ago (with a different organisation this time), and the second is a trial of a water gadget called Plantsurge which I was given to try at Malvern Spring Show earlier this year. Most of you have probably heard of biochar already and the claim that this inert, carbon-rich material can help soil fertility and plant health. The RHS information in the above link says results can be mixed, with reduced effects found in alkaline soils. This may help to explain the lack of difference I found in my previous trial as VP Gardens is on a lime-rich soil. Plantsurge is a different beast altogether. It's a strong magnet which is attached to a hosepipe as shown in the photo above. It's claimed that it softens water, with the result more like watering with rainwater. The higher nitrogen found in rainwater is thought to be beneficial to plants. Gardener...
Read more