Get rid of sphagnum!
Sphagnum adds a large amount of CO2 emission
Global warming and climate changes – there’s a great focus on CO2 emission and what individuals can do for the environment.
As a garden or greenhouse owner, you probably don’t know that you might be contributing with 2.4 billion pounds of CO2 emission in the air. 2.4 billion pounds is what they in Denmark use on sphagnum and half of it is for growbags in the greenhouse or acid soil beds in the garden. Of every pound, you use 1 pound of CO2 emissions. The calculations are made by The Technical University of Denmark.
If every Dane emission 22,000 pounds of CO2, then 22 pounds comes from sphagnum. It does not seem a lot but is it even necessary to use that much?
Earlier the most common method of cultivation in the greenhouse was in fixed beds. The disadvantage of fixed beds is that you need to change the soil to avoid plant diseases. Capillary boxes are used more and more and with the growbag the irrigation has become much easier. Also, the greenhouse has become more of a conservatory and the floor has therefore been tiled.
The reason why sphagnum has become so popular is that it is a soil type that does not weigh much and it’s therefore easy to move. Also, it’s a matter that retains water and nutrients, and the porousness brings air to the roots.
Make your own growbag
An alternative to sphagnum is coconut coir from sustainable plantations. It is a product made from coconut shells, that is, total recycling. Coconut coir has the same qualities as sphagnum, it is easy, airy and retains water. It is not carbon neutral though. Nothing is, not even compost, but compared to sphagnum the CO2 emission is less and it does not devastate the raised bogs.
You can also use regular soil from your garden and put it in a bag or bucket with drainage. To get drainage mix in pebbles or potsherd. Mix the garden-soil with 1/3 compost or 2/3 loam, 1/3 manure added with 1-ounce lime for every 2 gallons.
Compost from your own garden is perfect for tomatoes.
Photo: Grøn Kommunikation
Trees hardly have an adverse impact on the atmosphere with more CO2, not even when burning it for energy. The CO2 emission happens only during transport and cutting. The reason is that trees use CO2 from the air when growing. When the tree then is burned or rot it releases the CO2 again, which is then absorbed by other trees.
The profit for the climate is when the tree is burned instead of rotting because the energy from the tree is used instead of getting it from coal, oil and gas. You avoid having an adverse impact on the atmosphere with CO2 that is not already in the plants’ carbon cycle.
The prerequisite for the trees’ CO2 neutrality is that the forest area is conserved and that there is not cut more than sowed. This prerequisite is met in the forestry in Europe and North America.
The problem of using sphagnum is that it releases millions of years of storing CO2. This means that it releases a greater amount of CO2 than the plants can manage to absorb.
Om Lars Lund
Danish horticulturist and journalist
Lars Lund has for many years engaged in the garden and greenhouse. Lars has published many books about greenhouses, and he has participated in many Danish horticultural TV shows. He is a walking garden encyclopaedia, and he has answers for most basic cultivation questions – also the more ambitious ones.