If you are planting your tree in open ground (as opposed to training against a wall or fence) it is possible the tree will need supporting. In most cases it is the rootstock which determines what is required - some trees will need support for their entire lives, and will therefore require a permanent stake or post, whilst some will need a temporary post or stake for a few years to help them get established.
The following table shows what to use - start from the top and use the first entry that matches your tree:
|What are you planting?||Stake needed?||Explanation|
|Any apple tree on a dwarf rootstock.||Permanent stake||A permanent stake or other permanent support is essential because trees on dwarf rootstocks cannot support themselves.|
|Any apple tree or other fruit tree on a semi-dwarf rootstock||Permanent stake||It is best to assume a permanent stake or other permanent support is required. You may find after 4-5 years that trees on some of the more vigorous semi-dwarf rootstocks may become self-supporting.|
|Any fruit tree grown as a central-leader or spindlebush form.||Permanent stake||For gardeners who prefer fruit production over garden aesthetics a central-leader form, such as a spindlebush, in conjunction with a permanent stake is a good choice for production and fruit quality.|
|Semi-mature fruit trees (older than 3-4 years when transplanted).||Temporary stake||When trees of this age are transplanted much of the root system will be damaged, whereas the canopy of the tree is probably well-developed and intact. A substantial temporary stake (or possibly two) will be needed to hold the roots immobile in the ground for several years until the tree re-establishes itself.|
|Any fruit trees grafted on semi-vigorous or vigorous rootstocks.||Temporary stake||Although fruit trees on semi-vigorous and vigorous rootstocks soon become free-standing trees, a stake helps to get them started, especially if the climate is windy or the soil is loose. This need not be substantial - a heavy-duty bamboo cane will be suitable.|
If your tree needs a permanent stake, this should be planted before the tree if possible, because banging in a permanent tree stake requires a large hammer - and you don't want to accidentally hit your new tree.
Permanent tree stakes are usually wooden posts 6ft - 8ft / 2m - 2.5m tall by about 2" - 3" / 5-7cm, sharpened at one end and treated with preservative. Metal stakes (e.g. used for grape vines) are also suitable. In either case the best way to plant the stake is to start a pilot hole using a crowbar, then lift the post and force it bodily down into the pilot hole as far as it will go. Then use a hammer or post-knocker to bang the stake firmly into the ground.
If you are using a wooden stake you can prevent the top of the stake from splintering under the hammer by putting a metal jam jar lid over the top first. The stake will probably need to go in 2ft / 40cm-50cm or more depending on the type of soil - but it is easy to tell when it has gone far enough, because it will be firmly in the ground but still with a bit of give. Check the alignment as you bang it progressively further into the ground.
If your tree needs a temporary stake, you can go ahead and plant the tree first.