Page 26 - Simply Vegetables Autumn 2023

Peat Free Growing Media
I made a brief comment in the July Simply Vegetables about the problems I had with growing media this year
and have commented about peat free composts in the past. The government’s target is for amateur growers to be peat free by 2024 (I believe Scotland may
be different) so time is running out. Commercial growers have a bit longer, but pressure is on them to also go peat free. We have little choice but to comply unless you have your own peat bog! Which Irish members might! Growers
in Eire will no doubt be aware of if and when they have to go peat free.
I fully understand and accept that damaging peat bogs to extract peat for growing media is not sustainable as they are a major carbon dioxide store as well as providing a habitat for a range of animals, insects and plants. What winds me up (and it does not take much these days!) is the government has not put any money into funding research to find a decent substitute and have left us with a problem, typical politicians! This is one of the reasons commercial growers have not gone peat free in big numbers as many are having
to carry out trials to find a consistent and reliable growing media.
I have tried three different peat free composts and all three were bloody terrible, in other words rubbish and in one sense they were literally composted garden waste. Germination was poor with stunted pale-yellow seedlings which made little growth over a two month period. Most peat free composts are unreliable, inconsistent resulting in poor or no growth and are now expensive. In the local garden centre 60 litre bags were £12 to £15 a bag which for what is in them is extortionate.
Having had my rant the main purpose of this article is to look at the alternatives and what are the options. But before I do that why am I so keen on peat, put simply it is very consistent, reliable reasonably priced, partially sterile and was a perfect substrate for growing plants whether from seed or cuttings and plants up to a large size like tomatoes in containers or growbags.
So what do we require from a growing media, also called compost but is not the same as the compost from the compost heap, at least it should not be! A good growing media should be:
• Partially sterile (contain no weeds or seeds or pests and diseases)
• Hold some water but not be waterlogged. • Hold nutrients.
• Have a good physical structure to ensure
the right balance between water and air. • Provide anchorage for the plant
• Have a good air-filled porosity (has
spaces to hold air so oxygen is available
for the plants roots)
• Not contaminated. So no poisonous or
toxic substances
• Is reliable and consistent (every bag is
the same)
• Have a good CEC (Cation exchange
capacity, the ability for the plant to take
up nutrients)
• Has a suitable pH
• Possibly contain beneficial organisms, an
advantage of soil
• Ingredients are easily available and not
too expensive
Basically it needs to provide food, water and oxygen for the plants.
What are the options available to us? Do some research and find a decent growing media, one problem with this
is that the formulations of many of the existing growing media changes every couple of years as some of the ingredients become short and alternatives have to be used. They also seem to be getting more expensive even allowing for inflation. The other option is to make your own which
is not as difficult as it may appear and I want to look at this process in the rest of the article starting with the ingredients available.
The following are used in growing media
1-year old leafmould
or have been in the past:
• Bark – fine or medium
• Wood fibre or small chips
• Coir
• Composted green waste – from
municipal compost system
• Anaerobic digestate
• Soil / sand
• Leaf mould
• Sawdust
• Straw
• Paper waste
• Homemade compost – which let’s face it
could be as good as municipal compost
and a dam sight cheaper!
Considering a number of the above are waste products you would have thought bags of growing media would be cheap as they need to get rid of the material, yet prices seem to be rising – I wonder why?
Looking at the above ingredient in more detail starting with the organic ingredients. Bark This is mainly fine pine bark but some other conifer barks are used and a
26 Simply Vegetables
Poor quality compost
Progrow heap
KELVIN MASON