If you thought the winter months to be a season without planting, think again, you can indeed plant trees – bare-rooted trees. The following is an extract from The Fruit Tree Handbook by Ben Pike.
There a few simple techniques for planting a bare-rooted tree, and care taken at this time will reward you later on. More fruit trees die from mistakes made at planting time than from any other cause.
Planting bare-rooted trees
Bare-rooted trees are grown at the nursery and then dug up or lifted from November onwards for sale to the public. Because they are dormant at this time, they can be kept out of the ground for a week or so, as long as the roots do not dry out. For this reason, they will usually be wrapped in a plastic sack, often with damp straw around the roots to aid moisture retention. If the trees are well packed, so that the roots don’t dry out, they can be kept in their packaging for up to a week. Damp leaves or straw can be added around the roots to keep them damp. They should be kept in a cool but frost-free environment. Bare-rooted trees can be planted from late November until early March, while they are still dormant. Planting earlier in this season is ideal, so that the roots have time to establish before winter frosts cool the soil down, but planting at any time during the winter is fine. When the trees arrive from the nursery, they can be planted straight away, as long as the soil is not waterlogged or heavily frosted. If the soil sticks to your boots, wait for it to dry out further, as planting in these conditions will usually result in damage to the soil structure.
Keeping bare-rooted trees for longer than a week
If you wish to keep the trees for longer than a week before planting, you can heel them in. This involves loosely planting the trees in bundles in prepared holes or trenches. They can be kept for months like this, providing the soil is well packed around the roots. If you need to keep the trees into the early spring, a shady position will help to keep them dormant for longer. Remember that you will need to protect the trees from rabbits, either by using individual rabbit guards, or, if the trees are bundled together, by tying sacking or a similar material around the lower trunks (see page 80 for more information on rabbit protection). Rabbits can kill a tree in one night, so do protect them straight away.
Planting a bare-rooted tree with a stake
Most fruit trees will benefit from the stability that a stake provides while the roots become established. If trees on vigorous rootstocks are staked, the stake can be removed after one or two years. Trees grown on more dwarfing rootstocks require the support of a permanent stake, while trees on semi-vigorous rootstocks, such as MM106 or Quince A and C, can have their stake removed once the roots have established, usually after about five years.
Tree stakes need only reach 0.5m (1’8″) above ground level. This allows most of the tree to flex in the wind, which encourages root formation. If too tall a stake is used, the tree can become reliant on the stake for support instead of developing strong roots. The exceptions to this are trees trained as pyramids or spindlebushes, which have a permanent tall stake.
For planting, you should preferably choose a damp, overcast day without too much wind. On a cold, windy day the roots can dry out very quickly. Tree roots should not be left uncovered for more than two minutes in such conditions. If the roots are at all dry, it is a good idea to soak them in water for one or two hours before planting.
The planting hole should always be dug on the same day as planting. Digging holes in advance risks them filling with water on heavy soils, and can compromise the soil structure. Dig a hole a little deeper than the depth of the roots and twice the width. If you are planting into grass, you can dig the hole slightly deeper, and bury the turf underneath the tree. This will help to feed the tree as the turf decays. Always keep the good-quality topsoil separate from turf or subsoil. If you are planting on a slope, it is best to keep the excavated soil on the up side of the planting hole, because it is much easier to replace the soil from above the hole.
Now present the tree to the planting hole. You should be planting the tree at the same depth as it was planted in the nursery – or, in other words, the soil around the tree should be at the same height as the soil mark on the trunk. If you are not familiar with this process, it will help to place a straight piece of wood from one side of the hole to the other. Look to see that the soil mark from the nursery planting is at the same height as the wood. Some nurseries keep their trees in mulch once lifted, which can make a false mark on the trunk of the tree. Another way to check is to ensure that all the roots will be covered by soil, together with a few centimetres (one inch) of the trunk.
What is most important is that the union (see photo on page 29 / Diagram 15 on page 100) is well above the level of the soil around the tree.
If the union is at soil level or below, the scion can form roots – definitely something to avoid. Also, check at this stage to see if there is any damage to the roots; if so, prune this out with secateurs, back to healthy roots, just as you would prune growth above ground.
Once you have checked to see whether the tree fits correctly in the planting hole, place it back into the sack while you finish preparing the hole. With a fork, loosen the bottom and sides of the hole. This will help the roots to establish more quickly. This is particularly important on clay soils, where there is a danger of the clay puddling to form a sump, where the water will fail to drain properly.
Next, use an iron bar to begin the hole for the stake in the base of the planting hole, near the middle but slightly towards the direction of the prevailing wind. Use a lump hammer or sledgehammer to hit a wooden stake vertically into this hole.
The stake should protrude around 0.5m (1’8″) above the ground. Now take the tree out of the sack and place the roots into the hole, so that they fit well around the stake, with the trunk vertical and close to the stake. If you choose to use bonemeal or mycorrhizal fungi (see page 82), add this to the excavated soil at this stage.
Now place the tree in the planting hole and, while holding the tree upright, replace the good-quality soil around the roots. This can be tricky for one person, as using a spade needs two hands, so the careful use of your boot, or the help of a friend, are helpful tactics. Shaking the tree will help to spread the soil evenly around the roots, avoiding air pockets. When the hole is full, gently compact the soil with your foot.
Once the tree is planted, fix the tree to the stake with a tree tie. There are various types available: those with a high rubber content are ideal because they stretch as the tree grows. There must be some form of collar to keep the trunk away from the stake. For the same reason, the tree should be tied tightly to the top of the stake. This avoids the risk of the tree blowing around and being damaged by the stake. Where this happens, a wound will occur, which can become an entry point for diseases such as canker. More trees die from incorrect staking than from any other cause. Old stockings can make acceptable tree ties, but do not be tempted to use materials such as rope, which will cut into the trunk of the tree.
If you would like to read more from The Fruit Tree Handbook you can find more information and links to purchase it here.