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Reusing Growing Media · Hydroponics Daily

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  Hi, welcome back to Hydroponics Daily. I'm Dr. Russell Sharp and today we're
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  talking about reusing growing media.
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  So a lot of growing media can be very expensive and so it's very tempting to
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  reuse it and it's often a good thing for the environment to reuse it and it
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  can be a good thing for your plants but it depends on the situation.
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  So the first problem is that you often
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  pump your plants full of a lot of fertilizer and
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  then you might start again the next year with
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  the same grow media and it's still got a lot of salts in
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  there and these salts can build up so the first thing
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  I would do is run some water through the grow media and check the EC the electrical
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  conductivity of the water that comes out the liquid that comes out the solution
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  because if that's too high then you're going to really struggle to germinate
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  a seedling or get a seedling to grow in that grow media.
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  So you might want to do a flush of that grow media first to get the EC level down.
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  And then the other thing, obviously, when it comes to grow media is that when
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  you're reusing it, you're reusing it from a situation where the plant will often become root bound.
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  And so there'll be a lot of roots in that grow media. So you can get the root
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  ball and smash it to separate out the roots.
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  Some companies do sell enzymes to break down.
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  The roots that contain things like cellulases, lignases, and often they're based
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  on the enzymes from washing powder.
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  So often they don't work very well. But some companies out there might be saying,
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  hey, we sell fabulous products that are designed to break down plant roots.
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  The way I would do it is I would just compost the
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  grow media in its own dedicated compost bin
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  or just a normal bin with holes
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  thrown in it and that's what i do in my greenhouse i put
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  all the grow media into this big bin and then
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  i add some worms some tiger worms that are
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  designed to break down grow media and then
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  i'll put some food waste on top and i won't
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  incorporate it in i just put it on top and the worms will come up and get it and then
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  they will take the nutrients from that food and
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  they'll incorporate that they'll produce worm
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  castings which are really good for plant growth and
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  more importantly they'll break down the plant roots that are in that that grow
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  media so when i come to grow again in the spring or whenever after a few months
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  then the the roots will have broken down so that it's just like fresh grow media
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  really but you can see the worm castings in there and you could you could do
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  a 50 50 with some cocoa ads i often add some cocoa.
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  Coir fiber into there to bulk it bulk
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  it out because obviously organic based grow media peat
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  or cocoa will break down it will
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  decompose so you might want to add a bit of fresh every year
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  when you're regrowing it and then the big problem with reusing grow media can
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  be in certainly in the crops that can't be named the crop that can't be named
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  people who use growth regulators so never advisable to use growth regulators
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  these are highly toxic chemicals that.
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  Are that have deleterious effect
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  on human development especially and they
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  are extremely persistent and so if you've got
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  them in growing media it's very difficult to break them down i once looked
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  at developing a product that was contained a couple of
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  active ingredients that would break down growth regulators so people could
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  reuse their their grow media for certain crops
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  but there was no real market there was
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  a market for it but there was no uptake from distributors and
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  people like that so if you're interested in developing a
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  product that breaks down gross regulators so you can reuse gross media in
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  crops that use gross regulators then you
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  know speak to me they've got a couple of ideas that can
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  be done it's a question of is it economical to
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  sell a product to reuse grow media and then the
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  other thing was the grow shops were making a
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  lot of money from selling grow media to people saying you can't reuse your
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  grow media so you know it might have been a
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  shop killer as they call it a product that's a shop killer often gold leaf
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  or liquid gold is described as a shop killer because it contains
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  every essential plant nutrient and it dechlorinates and it
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  ph ups and ph downs but sometimes there's.
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  A call on the market and the and the end user wants wants
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  a product so much that they're prepared to to stock it
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  and maybe a growth regulator destroyer for grow
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  media so people could reuse their grow media would be a good thing certainly good for
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  the environment and i'd rather people didn't use growth regulators at
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  all but if they are going to use them they could reuse their grow media if
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  they did that that's just a certain one and then
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  when it comes to rockwool obviously i'm talking about cocoa and organic stuff
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  there but if you look at like rockwool or
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  mineral wool that's very difficult to reuse
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  because the roots are in there and and break down and you
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  can't compost rockwool because it's it's not going anywhere and you
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  can't dispose of it easily unlike organic grow
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  medias if it's cocoa based hydroponic systems
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  then you can just put it on the garden you can give it
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  to a farmer you could give it to a solvent allotments you could
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  do all sorts of things with it but rockwool it's
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  really just landfill so another disadvantage of rockwool based systems there
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  if you know of an end use for rockwool let me know because i'd be interested
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  to know but i think it just goes to just disposed of in landfill so if you can
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  be recycled that'd be interesting can you reuse it,
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  i i'm not aware of it but if you do let me know that's been hydroponics daily
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  for today reusing old grown media.