In order for firewood to burn most efficiently, it must be dry. If you already have a hot fire going, you can sometimes put wet wood on it and get it to burn in the right conditions. But wet or green wood is hard to ignite, produces less heat, creates more smoke and creosote buildup in your wood burning equipment.
Drying wood is not difficult, but it does take time. Wood that is green takes considerably longer to dry than seasoned wood that is wet from being out in the rain. Green wood is wood that is fresh cut from a live tree and still has living cells full of moisture. Once those cells have died and have become dry, the wood is considered seasoned. Seasoning firewood that is green can take from 6 months to a full year or more, depending on the conditions.
Once a tree is cut down and no longer receives moisture from the roots, it can begin to dry. If the foliage is left on, the leaves will continue to pull moisture from the wood and can help dry the wood fairly quickly. But for most people, it is not practical to store a whole tree while it dries. So the best way is usually to cut the tree up as soon as possible. A whole log without foliage can take a long time to dry. But once it is cut into firewood sized pieces, there is much more surface area for moisture to evaporate from. Especially when split.
Direct sun and air circulation will greatly speed the drying process. A lot of people want to immediately cover firewood, but if it is wet or green, covering it can slow it’s drying by blocking air flow and shading it from the sun. If the weather is rainy, you can leave it out in the rain until the weather dries. If it’s green or wet already, it’s not going to matter. Some even argue that green wood actually dries faster after it has been out in the rain for a while. That may sound a little strange, but after enough experience with this, I am starting to believe it.
You can dry wood indoors in a shed or garage, but I like to leave green wood outside to dry. This way it gets exposed to sun and open air and will dry faster if your climate is warm and dry. If you store it indoors, make sure the building is well ventilated. A closed up shed can inhibit drying.
Stacking firewood can also help it dry faster than if it was in a big heaping pile. Staking it gets it away from ground moisture and improves air circulation. It can help a lot if you stack the wood with least a few inches of space between the stack and any other objects, including other stacks, to allow the air to circulate around it. Learn more about stacking firewood.
Once the wood is dry, it will need to be covered to keep wet weather off of it. If you dried it outside, you can bring it indoors into a shed or other covered structure, or you can cover it outside. A tarp or plastic sheeting is a common way to cover firewood. This works well, but it is best if you cover it so that air can still circulate into the pile. You can do this by covering the top of the pile to keep the rain off, but leave the sides of the pile open. Otherwise any moisture that gets in will often stay in and the cover can sweat on the wood and you can end up with a moldy wet mess.
If covering it with a tarp or plastic, you will have to anchor it down so the wind will not blow it off. I usually do this by weighing it down with pieces of firewood strategically placed all around on top of the plastic to hold it down. These pieces will get wet but that is fine, they can eventually be dried and used after they are done with their job.
The climate you live in can greatly affect how your wood dries. In a hot dry climate wood will dry much faster than it will in a cool damp climate.