Plant Fruit Trees Correctly in March: Keep the Graft Union Above Soil

Spring arrives, garden centres are busy, and before you know it an apple, cherry or peach tree is in the boot of the car. At home, a neat planting hole gets dug, the tree is put in “well protected” - and that is exactly where the trouble starts. A tiny area at the base of the trunk determines whether your fruit tree later drips with blossom or limps along for years.

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

Why “planting extra deep” is a misconception

A lot of people assume that the deeper a tree sits in the ground, the more securely it stands - and the better it will cope with wind and weather. So the base of the tree is generously covered with soil and firmly pressed down. It sounds sensible, but for fruit trees it is usually a serious mistake.

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 vulnerable point. This is precisely where it needs oxygen exchange, dryness and light. Instead, it ends up with waterlogging, rot and fungal problems.

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

Damp soil and bark - a risky combination

The bark on the trunk is made for life in fresh air, not for constant wetness under the soil. Roots can tolerate persistent moisture; bark cannot. Moisture builds up around the trunk, especially in clay soils or after heavy rainfall.

Hidden consequences include:

• Fungi establish themselves and attack wood and bark.
• The bark starts to rot and may partially slough off.
• The transport tissues for water and nutrients are damaged.
• The crown is under-supplied and stays weak.

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

The critical zone: root collar and graft union

How to spot the sensitive areas on the trunk

With almost all nursery fruit trees, the rule is: they are grafted. In other words, a desirable variety - for instance a particular apple or a sweet cherry cultivar - has been joined to a tough rootstock. You can see this join on the trunk.

Two areas matter most:

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

That slight thickening on the trunk is the key marker. It shows 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 centrepiece of the future fruit tree.

Why the graft union must never be buried

If you cover the graft union with soil, the grafted variety may try to form its own roots there. Professionals call this “becoming self-rooting”. It may sound intriguing, but it creates problems for the tree.

What happens then:

• The advantages of the rootstock (growth control, resilience, early fruiting) are lost.
• The tree invests energy in emergency roots rather than blossom and shoots.
• Flowering is significantly delayed or may fail completely.
• The tree can grow far taller or more vigorously than intended.

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

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

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 lightly covered - better still, keep it visible. The trunk itself should never be under soil.

How to do it in practice:

• Dig the planting hole so the roots have plenty of room.
• Form a small, firm mound of soil in the centre of the hole.
• Place the tree on this mound and let the roots fall naturally downwards.
• Position it so the graft union sits clearly above the surrounding ground.
• Only then backfill from the sides and gently firm the soil.

If you are unsure, lay a cane or spade across the top of the planting hole while you work. It makes it easy to judge the finished soil level and check that the trunk has not slipped too low.

How to prevent the soil settling later on

Freshly loosened soil contains a lot of air. After rain and watering, it settles noticeably in the first few weeks. What looked perfect on planting day can end up too deep shortly afterwards.

Simple ways to avoid that:

• Properly firm the mound in the planting hole - don’t just heap it loosely.
• As you backfill, lightly tread the soil in layers, not only at the surface.
• After the first thorough watering, re-check the height and remove a little soil if the trunk is sitting too low.
• Create the watering basin with space around the trunk, not tight against the wood.

"Spending a few extra minutes getting the height right at planting time can save you years of frustration with weak, struggling trees."

Warning signs: how a “livingly buried” tree calls for help

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

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

• Short, thin branches with little vigour.
• Sparse or yellowing leaves despite normal watering.
• Flower buds that dry out and never open properly.
• An overall sense of “standstill” while other garden trees burst into growth.

Many people blame nutrient deficiency, poor pruning or pests. But the cause is often closer to the trunk: too much soil in the wrong place.

Rescue job: exposing the trunk without harming the roots

If you suspect your tree has been planted too deep, you can correct it afterwards. Done carefully, it is straightforward:

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

Young trees, in particular, often respond to this rescue step by pushing far more growth and producing their first proper blossom the following spring.

Quick reminder for a thriving orchard

Checklist right at the planting hole

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

• The graft union is clearly visible and at least a hand’s breadth 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 pulled off-line by settled soil.
• A stake supports the tree - not soil banked up against the trunk.

Tick these off and you create the conditions for sturdy, long-lived trees that can manage without harsh chemicals and still crop reliably.

Why fruit trees are especially sensitive to planting depth

In ornamental borders, some shrubs will tolerate being planted a bit deeper. Fruit trees are much less forgiving because their entire system is tuned to the graft. The pairing of rootstock and variety determines height, stability, disease susceptibility and when cropping begins.

Plant too deep and you disrupt that finely balanced set-up. The tree has to reorganise itself, produces emergency roots, and at the same time fights rot at the trunk - leaving too little energy for abundant blossom and fruit.

Especially in home gardens where many people prefer to avoid chemical treatments, it pays to look closely at the base of the trunk. A free, visible root collar and a clearly exposed graft union are among the simplest - and most effective - steps for a healthy, productive fruit garden.