Not that peat-based compost is perfect for longer term small-pot plants. It tends to compact. I make a 50% vermiculite blend. Or did. For plants needing better drainage I mix equal parts JINo3/peat-free compost/small grit or perlite. The latter seems to work for DIY bonzai. Of course it would be much better just to buy it ready-made.
I pretty much use 70/30 JI3 and fine mulch for everything unless it needs extra grit.
Whilst its not strictly relevant to @bede's initial musings I thought this might be of interest, received this morning from one of our main commercial nursery clients -
"We are currently peat free on many of our herbaceous lines
and reduced peat on the rest of the stock. There is not a product out there
good enough for a lot of the shrub production currently. We are doing trials
every year but are yet to find a satisfactory peat free solution.
Hopefully there will be more improvements over the next
couple of years, however there is a sustainability issue with peat free
products; materials have to be sourced from all over the world to make peat
free and due to the nature of the compost, water usage and fertiliser usage go
up significantly. Not bad for growing pansies in Monty Dons garden but another
thing growing millions of containers!
As we stand, if a customer requests peat free stock there is
likely to be a 30-40% increase in price minimum with peat free compost to cover
the price of the compost (much more expensive) and production costs (losses,
slower growth rate, water usage, increased fertiliser)".
It seems their findings on growth rates are contrary to ours, however we work with larger container units so its not a direct equivalence.
My understanding is that the 2024 ban doesn't actually affect those in the commercial side of things.
I might go into business selling little P9 plants in 20lt pots of peated compost
In light of the compost industry’s failure to come up with an affordable peat replacement. I have decided that there are two solutions:
1. Make your own compost
2. Re-use old compost
or perhaps 3. a combination of both.
I already make an average garden compost. I also collect autumn leaves in large plastic bags and leave for ca 2 years to make leafmould.
I take actions 1 & 2 for the bottom part of outdoor pot plants. Suitably reinforcing with JI fertiliser or blood, fish and bone fertiliser. Topping the pots off with fresh commercial general purpose compost or John Innes.
The main problem with both solutions 1 & 2 is weeds and soil-born pests and diseases. I am now thinking of ways to sterilise the composts on a domestic scale.
What I have done in the past, is to add the compost to a container with about 1 inch of boiling water, putting on a lid and waiting. This has worked. The texture of the compost seems to be improved as a bonus. One only needs to reach 60ºC and hold for a few minutes. It works fr both gp-type and JI-type home-premixed composts.
Microwaving might also be a solution. I haven’t tried this yet.
Desparate times need desperate actions.
Any other ideas?
location: Surrey Hills, England, ex-woodland acidic sand. "Have nothing in your garden that you don't know to be useful, or believe to be beautiful."
Create a nursery bed for seeds, grow fewer annuals and focus on perennials, reduce the number of pots you have and grow plants in the ground instead. Change what you grow and how you grow it rather than/as well as trying to replicate what you do now with a different growing medium.
Sterilisation is not too much of an issue for most 'normal' plants - you may have to weed your pots and containers but that's not the end of the world. Avoiding bacteria isn't an issue for most garden plants except very young seedlings so keep your best compost/leaf mould for the most precious ones.
Gardening on the edge of Exmoor, in Devon
“It's still magic even if you know how it's done.”
Wouldn't heat sterilisation (microwave or any other way) kill off beneficial organisms? Or is that not a problem for compost/soil to be used in containers?
I've been mixing sieved homemade compost with the bought stuff this year and there are more weeds appearing - mostly forget-me-not seedlings which I would expect, and grass which I wouldn't given that my "lawn" grass doesn't get long enough to produce much in the way of seed heads, and silver birch seedlings that come in direct from the big tree across the road not from the compost. It's easy enough to pick them all out when they're small.
Doncaster, South Yorkshire. Soil type: sandy, well-drained
I wouldn't worry about 'killing off' anything good. It doesn't take much for microbial activity to return. Most composts are heat treated anyway, in fact home 'heaps' are better 'binned' for a more consistent and sterile end product.
My compost heap doesn't heat up enough. It is where it has to be for access and aesthetic reasons, it doesn't get sun, it gets ingredients added in the order they arrive, it never gets stirred, it's too remote to water.
But I am a bit sceptical about natural compost heating. If the bacteria or fungi or whatever can heat up the compost enough to kill weed seeds, pests and diseases, would not that kill off everything living? Bacterial suicide?
location: Surrey Hills, England, ex-woodland acidic sand. "Have nothing in your garden that you don't know to be useful, or believe to be beautiful."
My compost heap doesn't heat up enough. It is where it has to be for access and aesthetic reasons, it doesn't get sun, it gets ingredients added in the order they arrive, it never gets stirred, it's too remote to water.
But I am a bit sceptical about natural compost heating. If the bacteria or fungi or whatever can heat up the compost enough to kill weed seeds, pests and diseases, would not that kill off everything living? Bacterial suicide?
No doubt many pests, fungi and bacteria are killed but nutrient compounds will not be. Think of it like a clean petri dish of agar - its actually the perfect environment for the beneficial bacteria and micro fauna to quickly recolonise once the fermentation/heating process is over.
Appreciate its not a solution that works for everyone, hopefully you find a suitable solution.
Posts
"We are currently peat free on many of our herbaceous lines and reduced peat on the rest of the stock. There is not a product out there good enough for a lot of the shrub production currently. We are doing trials every year but are yet to find a satisfactory peat free solution.
Hopefully there will be more improvements over the next couple of years, however there is a sustainability issue with peat free products; materials have to be sourced from all over the world to make peat free and due to the nature of the compost, water usage and fertiliser usage go up significantly. Not bad for growing pansies in Monty Dons garden but another thing growing millions of containers!
As we stand, if a customer requests peat free stock there is likely to be a 30-40% increase in price minimum with peat free compost to cover the price of the compost (much more expensive) and production costs (losses, slower growth rate, water usage, increased fertiliser)".
It seems their findings on growth rates are contrary to ours, however we work with larger container units so its not a direct equivalence.
My understanding is that the 2024 ban doesn't actually affect those in the commercial side of things.
I might go into business selling little P9 plants in 20lt pots of peated compost
Very relevant.
"Have nothing in your garden that you don't know to be useful, or believe to be beautiful."
In light of the compost industry’s failure to come up with an affordable peat replacement. I have decided that there are two solutions:
1. Make your own compost
2. Re-use old compost
or perhaps 3. a combination of both.
I already make an average garden compost. I also collect autumn leaves in large plastic bags and leave for ca 2 years to make leafmould.
I take actions 1 & 2 for the bottom part of outdoor pot plants. Suitably reinforcing with JI fertiliser or blood, fish and bone fertiliser. Topping the pots off with fresh commercial general purpose compost or John Innes.
The main problem with both solutions 1 & 2 is weeds and soil-born pests and diseases. I am now thinking of ways to sterilise the composts on a domestic scale.
What I have done in the past, is to add the compost to a container with about 1 inch of boiling water, putting on a lid and waiting. This has worked. The texture of the compost seems to be improved as a bonus. One only needs to reach 60ºC and hold for a few minutes. It works fr both gp-type and JI-type home-premixed composts.
Microwaving might also be a solution. I haven’t tried this yet.
Desparate times need desperate actions.
Any other ideas?
"Have nothing in your garden that you don't know to be useful, or believe to be beautiful."
Sterilisation is not too much of an issue for most 'normal' plants - you may have to weed your pots and containers but that's not the end of the world. Avoiding bacteria isn't an issue for most garden plants except very young seedlings so keep your best compost/leaf mould for the most precious ones.
“It's still magic even if you know how it's done.”
These guys are mad for it - https://www.reddit.com/r/composting/
I wouldn't worry about 'killing off' anything good. It doesn't take much for microbial activity to return. Most composts are heat treated anyway, in fact home 'heaps' are better 'binned' for a more consistent and sterile end product.
But I am a bit sceptical about natural compost heating. If the bacteria or fungi or whatever can heat up the compost enough to kill weed seeds, pests and diseases, would not that kill off everything living? Bacterial suicide?
"Have nothing in your garden that you don't know to be useful, or believe to be beautiful."
Appreciate its not a solution that works for everyone, hopefully you find a suitable solution.