The Pros and Cons of Using a Shredder for Your Prunings

Shredders are one piece of garden equipment that people either can’t see the point of or wouldn’t be without.  Now that many localities have ‘green waste’ recycling a lot of gardeners are happy to part with their assortment of  woody clippings from bushes and trees, leaving just the green stuff for the compost heap.  However, for those who want to generate high quality compost a shredder can be important.  But are they worth the effort?

In fact there is a kind of cult following amongst gardeners who make lots of compost.  For most people the compost heap is given little thought and stuck in the most inconspicuous place in the garden when weeds and vegetable peelings can be thrown onto it and forgotten about.  For others the art of composting is a challenge in itself: a means to the heightened state of achievement called ‘hot composting’ where the heap is lovingly mixed and turned so that it ‘cooks’ at temperatures up to 150 degrees F (65 degrees C). This process has three important advantages:

• The compost is produced much more quickly, often in under four months.
• The compost is well balanced and often of a higher quality, particularly as nutrients don’t have much time to leach out of the heap.
• Perhaps most importantly, the higher temperatures kill off weed seeds so that sterile compost is produced.

In order to get hot composting going three things are necessary (see the website Compost-Info-Guide for details):

• A large enough volume of material, all ready to be composted at the same time.  Generally a 3ft cubed (1m cubed) compost bin needs to be filled.
• The correct mix of green material (nitrogen-rich), brown material (carbon-rich) and water (just damp and if squeezed will stick together slightly).
• Plenty of air.

It is the second and third requirements that make shredders invaluable: they chop the brown woody stuff into tiny pieces, meaning that the air and bacteria required to get hot composting going are able to act on far more of the surface area of the material.  This gets things cooking at much higher temperatures than traditional  methods.

From all of the above it sounds as if I fall into the category of people who love their shredders and can’t bear to be without them.  I do have moments when I feel this but I also hate my shredder at times.  Why?  Because it promises so much but makes it so difficult to achieve.  Here are my top reasons to hate shredders:

• They are slow to use.  In order to make them ‘safe’ for household use they have to have a small inlet that hands can’t get into.  So small in fact that very few branches will fit either without much pushing, cutting with secateurs and  poking with a stick.  It’s particularly bad with bushes that send off little branches in every direction.  Getting these into the inlet is no small task!
• They jam up.  This may be partly because my shredder is not the latest-and-greatest model but I find that after a while the shredded pieces don’t clear from the exit chute and it grinds to a halt.  This mostly happens when I put too much green stuff through without balancing it with enough dry brown material.  Once jammed, it has to be disconnected, a spanner used to undo the retaining bolt, opened and cleaned out before starting the whole thing again.
• They are awkward.  Goggles and earmuffs are essential to protect yourself from the odd flying bit of material and the terrible racket they make  banishes anyone else from the area (less of a problem with the ‘quiet’ shredders I guess but I don’t imagine that they are really that silent).

Last weekend I trimmed two bushes in my garden.  One is a buddleia which needs a lot of cutting back and the other needed to be halved in size.  After just over half an hour I had the bushes trimmed and the material ready for the shredder.  It took a further three hours to reduce this to shredded material, mixing in various weeds and other old plants.  At the end of this process I had produced enough material for just one hot composting bin.  I’m quite proud of the result but the whole process felt like I was fighting the shredder to get the job done.  Was it worth it, spending three hours of the weekend that I could have had with my wife and kids?  Perhaps, when I spread the compost on new young plants next Spring  I will say it was.  But part of me wishes I had just sent it all to the green waste recycling.  There must be an easier way...!