Don’t grow your own firewood
Having a stand of trees just for the purpose of firewood is a complete waste of space.
When I was first planning my block, I considered planting a stand of gums in the far back corner for firewood. It is a scheme I had seen on other small farms and having a supply of firewood was on my list of sustainable things to do.
An experienced old treecropper advised me against it.
“Plant trees,” he said. “You will always have firewood.”
A decade later I bless this man for his advice. I now firmly believe trees should fulfil multiple purposes, only one of which – their final one – is firewood.
My 3.5ha looked large and empty 10 years ago. Today, I no longer have the space for something as single purpose as a firewood block. Trees around here have to justify their existence and I’m quite demanding. They provide shade or fodder for our animals, fix nitrogen in the soil, stabilise banks, break the wind, provide fruit or nuts for our family, and food for our bees or the birds. When they have finished doing that, or when they get too big, or when I want to plant something else, they become firewood.
My first piece of advice is not to plant a woodlot just for firewood, but do plant trees which make good firewood. Plant a selection of trees that fulfil different functions and mature at different times so you have an ongoing, sustainable source of firewood. I have listed some suggestions (see pages 49-51), but it is more important that you choose trees that will do well in your conditions.
1 Plan ahead
Sustainability is not a short-term plan and a good woodlot is perpetual for generations to come, so think about harvesting while you’re planting.
Do the math
How many trees do you want to use each year? It’s a good question and is going to depend on how efficient your fire is and how quickly your trees grow.
To give you some idea, we have a large house with an open fire which I use extravagantly. It can be burning all day in winter, and we budget on seven tightlypacked cubic metres of wood each year. Some people only use two.
Depending on what and when you harvest, seven cubic metres could be from 21 young trees to two or three big old ones, but a median would be about 7-8 trees a year.
Leave some access space
You need space to fell the mature tree, and you need to be able to get the trailer or tractor to it to cart the wood out. You are going to be older when you are harvesting your firewood, so make it easy on yourself.
Stagger your trees
Growing your own firewood is not an allin, all-out job. You want a few trees each year for the rest of your begotten life. If you have the space to plant a few extra, you can share them with a mate who helps you to chop them down and up, making harvesting a more sociable and easier task.
How to plant
Plant your trees close together, between 1.2m-2m apart. You want tall trees with a straight grain that are easy to split and close neighbours will encourage this upright growth. Close planting will also deter weed growth underneath.
Mix your trees up. Don’t plant a block of trees all the same type, same age. A mixed woodlot is more multi-purpose and sustainable which means if it’s managed properly, it will continue perpetually.
Some trees will encourage others to grow (companion trees). Some you will harvest in as little as six years, leaving more space for their neighbours. Some you will coppice, cutting back to the stump which will quickly regrow and replace itself.
The biggest cost of planting out a woodlot
It is not the tree themselves that are the major cost. It is the fencing and the time required to do it, and then the time required to plant them out.
Trees can be sourced from other trees. Literally planting an acorn in the ground is how nature has planted oak trees for millions of years and it works wonderfully, especially in oak-leaf compost.
4tips for maintaining your woodlot
Once planted (and plant well, with compost and mulch to get them growing), mark where each tree is. One suggestion is a metre-high pole, colour co-ordinated for each species. In spring, the grass (and maybe also other weeds) is going to grow
“Trees should fulfil multiple purposes, only one of which – their final one – is firewood.”
and smother your new young tree. For the first couple of years, in spring and autumn, you are going to have to go and find each tree and ‘release’ it from the overpowering weeds. Having a locator pole makes this job much easier.
If you have pests, invest in something like KBC shelters. For $6.50 they provide protection from rabbits and pukekos, a thermal shelter, and make locating (and even spraying) easy. The bonus? They are re-usable.
Like all plants, firewood trees need food to grow strong and fast. Fertilise or mulch with compost to get faster, bigger wood and healthier trees.
Prune to remove any double-leaders and open-up anything being used as a wind break. You want these to filter and slow the wind, not stop and dump it.
The idea is to harvest your firewood trees before they grow into huge, dangerous, gnarly and hard-to-split behemoths. Wellfertilised trees in the right conditions can be ready five years after planting, when they are still small enough to fell easily and don’t need to be split.
Remove alternate trees to leave space for others, or choose a variety of woods for the fire, ie some for high heat, some for easy splitting into kindling. You can also choose to cut out the largest or just take out any you don’t particularly want.
You want to fell your firewood tree in winter – at least four weeks before bud burst in spring – for several reasons. • it gets you warm and it gets the job out of the way before the busy growing and holiday seasons; • importantly for deciduous trees (those that lose their leaves in winter), by this time of year they will already be halfdry as they have half the amount of sap running through them in winter as they do in summer; • they will have less sugar in them which is what fungi (rot) grows on, so there is less chance of this too; • if you leave a fallen log to burst into bud (or if it has leaves/needles on it, for these to wither and die) this will draw even more moisture out of the wood. • if you are coppicing your trees, you’ll get good regrowth in spring. • most of the trees I’m about to mention, if felled in winter, will be ready to burn the following winter. The exceptions are chestnut, elm and gum and most conifers (including common radiata pine) which take longer to dry properly.
you want to fell your firewood trees in winter, at least four weeks before bud burst in spring.