Although a more efficient fuel source, hardwood can be difficult to ignite from cold. Softwood kindling is therefore best used to start a fire, as the resinous and fibrous nature of softwood helps it to burn from cold. Once a fire is established and there is some heat in the base of the fire, it should be fueled with hardwood to maintain a slow burning fire with good heat output.
Softwood can produce a very pleasing flame to look at, but it will burn very quickly and you will go through a large amount of wood in a very short time.
All wood should be well seasoned before burning. Different woods have different initial moisture contents, often determined by where a tree grows. Willow, for example, tends to grow in moist soil or near water, so its wood has a high moisture content and requires longer seasoning. Firewood should have a moisture content of less than 20%, at least for burning. The density of the wood also affects how long it needs to be seasoned. Oak is a very dense wood and can take up to 2 years to fully season.
Hardwood
List of common hardwood to use as firewood
Alder
Opinions vary but it is generally considered as a poor firewood. It burns quickly and gives off little heat.
Apple
Needs to be seasoned well. Burns slowly with a good heat output and produces a pleasant smell with little sparking or spitting.
Ash
One of the best firewoods and has a low moisture content when green. It can be burned green but like all wood is best when seasoned. Gives a good heat output, good flame and burns slowly.
Beech
Beech has a high water content and needs a long seasoning period. Burns well but has a tendency to spark.
Birch
Birch burns easily and can be burnt unseasoned. It also burns very quickly so is often best mixed with a slower burning wood such as Oak or Elm. Birch bark can make an excellent fire-lighter.
Blackthorn
Another good firewood, burns slowly, good heat output and little smoke.
Cherry
Needs to be seasoned well. Burns well with a pleasant smell and without spitting.
Elder
Burns quickly with little heat output. Produces lots of smoke
Elm
A good firewood but due to its high water content it must be seasoned very well. It may need assistance from another faster burning wood such as Birch to keep it burning well. However it gives off a good, lasting heat and burns very slowly.
Hawthorn
Good firewood. Burns well with good heat output and little smoke. Hawthorn can be difficult to split as straight lengths are rare.
Hazel
Excellent firewood. Burns quickly without spitting
Holly
Can be burnt green. A good firewood
Hornbeam
Good firewood. Burns well
Horse Chestnut
A low quality firewood, spits a lot.
Lime
A low quality firewood
Oak
One of the best firewoods but needs a long seasoning period due to its density. Burns slowly and is long lasting. On smaller stoves it is best burnt in smaller pieces than other woods.
Pear
Needs to be seasoned well. Burns well with a pleasant smell and without spitting.
Plane
A usable firewood
Rowan
Good firewood. Burns well.
Sweet Chestnut
Burns when seasoned but spits continuously and excessively. If burning on an open fire, be wary of flying sparks.
Sycamore
Good firewood. Burns well but only produces a moderate heat output.
Walnut
A low quality firewood.
Willow
Willow has a high water content so only burns well when very well seasoned.
Yew
A usable firewood.
Softwood
List of common softwood to use as firewood
Cedar
A good firewood which burns well with a pleasant smell. Gives off a good, lasting heat but little flame. Doesn't spit too much and small pieces can be burned unseasoned.
Douglas Fir
Not a very good firewood, produces little flame or heat.
Larch
Needs to be seasoned well. Spits excessively while it burns and can produce a lot of soot deposits that can line the flue, firebox and glass window of your stove.
Pine
Burns well but tends to spit and can leave sooty deposits. The resinous wood makes good kindling.
Poplar
Burns slowly to produce a black choking smoke even when seasoned.
Spruce
A low quality firewood.