One way of producing your own fuel for heating your home is to grow your own firewood. Whilst this is easy to do it does take up a fair amount of space and has to be a long-term plan – even the quickest growing trees take a few years to reach the stage where they are large enough to be cut for firewood. Having said that, if you have trees that are not grown specifically for firewood, but more for decorative purposes or indeed fruit growing there will be times when you will need to cut them back for general pruning or if they are starting to obstruct paths or straying over into a neighbour’s garden. These cut back branches are useful in contributing to your collection of firewood.
The most efficient and sustainable method of “harvesting” firewood from trees grown specifically for that purpose is coppicing. This simply means that trees are cut close to their base and allowed to grow back. After cutting, shoots appear very rapidly, but it generally takes at least five years (more usually between 7 to 20 years) for these shoots to reach a size that is large enough to use for firewood. It should be noted that this is only really suitable for hardwood. Ideally you need a woodland of a few acres in size and rotate your coppicing over different areas to be completely self-sufficient in firewood. This is unfortunately not realistic for most of us. However, though growing a few trees and keeping decent sized prunings you can go some way towards being self-sufficient.
All wood that you are going to use for firewood should be properly seasoned (i.e. left to dry out). Not that you can’t burned unseasoned wood, it’s just that it will burn at a lower temperature (if you can get it to burn) and will tend to be rather more smoky and cause you to have a build up of deposits in your chimney.
So if you are growing trees for firewood or collecting firewood what trees should you be looking at? I have graded trees here in terms of best, medium and worst. What defines the best are those that burn at a high temperature and will season over a relatively short period. Typically the best firewood is hardwood which tends to have a lower moisture content.
Best Wood for Firewood
The following are some examples of wood that makes good firewood:
Ash, birch, blackthorn, hawthorn, hazel, hornbeam, maple, oak, rowan and sycamore.
Ash is traditionally the best as it has the lowest moisture content and in the right conditions it will be seasoned within just three months. You can burn ash when it is still quite green, although it will spit a bit. The other types of wood above are not far behind ash and will season in a similar time frame.
Next Best Wood for Firewood
Chestnut, elm, eucalyptus, fruitwoods, pine and willow all have medium burning rates and will be suitably seasoned in six to nine months. If you leave it to season for longer then this will improve the quality of this group of firewood.
Examples of Poor Quality Firewood
Some wood has a high moisture content which means that it takes a long time to season and even when it is well seasoned it will burn at a lower temperature. Alder, douglas fir, elder, leylandii and poplar are examples of this type of wood. Some larger pieces of this wood can take up to two years to season properly, although for smaller pieces you can get away with shorter periods. Whilst I am not saying you shouldn’t burn this (far from it in fact), I would suggest that you mix it with better quality firewood.
Using Timber for Firewood
Your other option for firewood is to use offcuts of timber, broken up pallets, wooden boxes, etc. This burns quickly and very hot, so is good for getting a fire going, but not so good if you are wanting to keep it going over an extended period. Therefore it is best mixed in with other firewood. From an environmental point of view it makes sense to use this as otherwise it would just be dumped in landfill. What you do need to wary of though is wood that has been treated as it may well give off harmful smoke when burned.
Ideally, you want a an indefinite supply of ash to keep you warm through the winter. However, you will want to make use of whatever wood you have available, so sometimes it is a matter of mixing your wood for the best results.