Planting fruit trees in March: keep the graft union above the soil

Spring arrives, garden centres fill up, and before long an apple, cherry or peach tree ends up in the boot. Back at home, you dig a neat planting hole, set the tree in “well protected” - and that’s exactly where the trouble can start. A tiny area at the base of the trunk determines whether your fruit tree later becomes covered in blossom or struggles on for years.

The most common planting trap: set too deep and slowly suffocated

Why “planting extra deep” is a misconception

Many people assume that the deeper a tree sits in the ground, the more stable it will be - and the better it will cope with wind and weather. So the base is generously backfilled with soil and firmly pressed down. It sounds sensible, but for fruit trees it is, in most cases, disastrous.

A thick layer of soil around the lower trunk acts like a heavy scarf pulled over your nose and mouth. It deprives the tree of air at its most sensitive point. Right here, it needs oxygen exchange, dryness and light. Instead, it gets waterlogging, rot and fungal infection.

"A fruit tree rarely dies dramatically - it suffers quietly for years when its trunk base disappears into the soil."

Damp soil and bark - a dangerous combination

The bark on the trunk is designed for life in fresh air, not for constant wetness underground. Roots can tolerate ongoing moisture; bark cannot. Moisture collects around the trunk, especially in clay soils or after heavy rainfall.

The hidden consequences:

• Fungi move in and attack the wood and bark.
• The bark begins to rot and may partially peel away.
• The transport pathways for water and nutrients are damaged.
• The canopy is under-supplied and remains weak.

From the outside, you often only notice that the tree “just doesn’t get going”. The real cause lies underground - buried at exactly the wrong point.

The decisive zone: root collar and graft union

How to identify the sensitive areas on the trunk

With almost all fruit trees from a nursery, the rule is: they are grafted. That means a desirable variety has been joined onto a tough rootstock - for example, a particular apple cultivar or a sweet cherry variety. You can usually see this join on the trunk.

There are two key areas:

• Root collar (root flare): the transition between roots and trunk, usually where the roots branch out sideways.
• Graft union: a small swelling, kink or scar slightly above the root collar.

This slight thickening on the trunk is crucial. It marks where the fruiting variety was grafted onto the rootstock. Many people overlook it or dismiss it as a “cosmetic flaw” - when in fact it is the central point of the future fruit tree.

Why the graft union must never be buried

If the graft union is covered with soil, the fruiting variety may start trying to form its own roots there. Professionals refer to this as the variety “becoming independent”. It sounds interesting, but it creates real problems.

What can happen next:

• The benefits of the rootstock (growth control, resilience, early fruiting) are lost.
• The tree pours energy into emergency roots instead of blossom and new shoots.
• Flowering is severely delayed or may fail entirely.
• The tree can grow much taller or more vigorously than intended.

"The graft union is, in a way, the fruit tree’s lungs: it has to breathe freely, otherwise the harvest stays meagre."

How to plant correctly in March: height, technique, checking

The ideal height: clearly visible above ground level

The basic rule for fruit trees is: the graft union should sit 5 to 10 centimetres above the final soil level. The root collar should be, at most, only lightly covered - better still, keep it visible. The trunk itself should never be underground.

How to do it in practice:

• Dig the planting hole so the roots have plenty of room.
• Create a small, firm mound of soil in the centre of the hole.
• Place the tree on the mound and let the roots fall down naturally.
• Align it so the graft union is clearly above the surrounding ground.
• Only then backfill from the sides and lightly firm the soil.

If you are unsure, lay a cane or spade across the planting hole while you work. It gives you a clear reference for the final soil level and helps stop the trunk from ending up too low.

How to prevent the soil sinking later

Freshly loosened soil contains lots of air. With rainfall and watering, it settles noticeably during the first few weeks. What looked perfect at planting time can end up too deep not long afterwards.

Simple ways to avoid that:

• Press the mound in the planting hole firmly, rather than leaving it loosely piled.
• When backfilling, lightly firm the soil in layers - not just at the top.
• After the first thorough watering, check the tree and remove a little soil if the trunk has sunk too low.
• Shape the watering basin with some distance from the trunk, not right up against the wood.

"Spending a few extra minutes getting the height right when planting saves years of frustration with stunted trees later on."

Warning signs: how a “live-buried” tree cries out for help

When the fruit tree simply doesn’t get going in spring

A tree planted too deep often shows distress only after months. In spring, certain symptoms become particularly noticeable:

• Short, thin shoots with little vigour.
• Sparse or yellowing leaves despite normal watering.
• Flower buds that dry out and never properly open.
• A general sense of “standstill” - while other trees in the garden take off.

Many people suspect a nutrient deficiency, incorrect pruning or pests. Often, the cause is much closer to the trunk: too much soil in the wrong place.

Rescue job: expose the trunk base without damaging roots

If you suspect your tree is sitting too low, you can intervene afterwards. Done carefully, it’s straightforward and doesn’t take much effort:

• Use your hands or a small hand trowel to gently scrape soil away from around the trunk.
• Keep going until the root collar and graft union are visible and open to the air.
• Take care not to injure the bark or cut off fine roots.
• Re-form the watering basin a little further away from the trunk.

Especially with young trees, this rescue step is often repaid as early as the following spring with noticeably more new growth and the first proper blossom.

Cheat sheet for a vigorous orchard

Checklist right at the planting hole

If you are planting several trees in March or April, a simple checklist helps keep things consistent:

• The graft union is clearly visible and at least a hand’s width above the soil.
• No pressed, damp soil is sitting against the trunk.
• The watering basin forms a ring and does not run along the bark.
• The trunk is upright, not leaning due to settling soil.
• A stake supports the tree - not a heap of soil against the trunk.

Tick these off and you create the basis for robust, long-lived trees that can thrive without harsh chemicals and still crop reliably.

Why fruit trees react so strongly to planting depth

In ornamental gardens, some shrubs will tolerate being planted a little deeper. Fruit trees are far less forgiving, because their whole system is tuned to the graft. The pairing of rootstock and variety determines final height, stability, susceptibility to disease and when fruiting begins.

Planting too deep disrupts this finely balanced system. The tree must reorganise itself, produces emergency roots, fights rot at the trunk at the same time - and simply has too little energy left for abundant blossom and fruit.

For home gardens in particular, where many people prefer to avoid chemical treatments, it pays to take a close look at the trunk. A free, exposed root collar and a clearly visible graft union are among the simplest - and most effective - steps towards a healthy, high-yield fruit garden.

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