Repotting guide

When & how to repot True Service Tree (Sorbus domestica)

Also called true service tree, sorb apple.

More about true service tree

About True Service Tree

Sorbus domestica · also called true service tree, sorb apple · edible

The true service tree is a long-lived, rare deciduous tree native to southern and central Europe, with ash-like pinnate leaves, creamy spring flowers and small apple- or pear-shaped 'sorb apples' to 2-3 cm. The fruit is hard and astringent until bletted, when it turns soft, sweet and richly aromatic, traditionally eaten fresh or fermented into perry-like drinks.

Mature size: Typically 10-20 m tall with a spread of 6-10 m, reached only over many decades.

Watch for — Slow establishment and poor fruiting in cool climates: A warmth-loving species that may grow slowly and fruit sparsely in cool northern gardens. Choose the warmest, most sheltered sunny spot available.

How to tell true service tree needs repotting

Repotting on a calendar is less reliable than reading the plant. For true service tree, watch for these signs:

Roots circling the bottom of the module or pot, or poking out of the drainage holes.
The seedling dries out within a day and growth has visibly stalled.
Roots are white and matted in a tight spiral when you tip the plant out.
It has outgrown its current container for the stage of the season — pot true service tree on before it becomes hard root-bound.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot true service tree

Pot on seedlings as they grow; not a perennial repot. True Service Treeis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Slow-growing, long-lived deciduous tree with an upright then broadly domed crown; can live for centuries and is among the longest-lived Sorbus..

What size pot to step true service tree up to

Pot true service tree on gradually — a seedling jumped straight into a huge pot sits in cold, wet, airless soil and stalls. Step up one or two sizes at a time as the roots fill each container, finishing in a large final pot or the ground. The aim is roots that never circle and never check.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot true service tree

Pot true service tree on through the active growing season, whenever roots fill the current container — there is no single date, just "before it becomes root-bound". Avoid potting on during a cold snap.

Step-by-step: repotting true service tree

Pot on before it is root-bound. Check true service tree regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
Step up one or two sizes. Choose the next container up — not a giant one. Cold, wet, unused soil around a small root system stalls seedlings.
Knock it out gently. Support the stem, tip the pot, and ease the rootball out without breaking it. A little teasing of circled roots at the base is fine.
Pot into rich mix. Set it into fresh deep, well-drained, fertile soil; tolerates chalk and limestone at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water true service tree in well and keep it in bright light; a freshly potted-on seedling can wilt for a day while roots settle, so do not overcompensate by drowning it. Do not fertilise for about 1 week — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for true service tree

True Service Tree wants deep, well-drained, fertile soil; tolerates chalk and limestone. Prefers warm, free-draining ground and is well suited to alkaline and calcareous soils. Avoid cold, heavy, waterlogged sites, which check growth and shorten its life. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting true service tree — frequently asked questions

How often should you repot true service tree?

Pot on seedlings as they grow; not a perennial repot for true service tree. True Service Tree is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into deep, well-drained, fertile soil; tolerates chalk and limestone so the roots never circle the cell, ending in a large final container. A root-bound transplant stalls and never fully recovers.

What size pot does true service tree need?

When is the best time of year to repot true service tree?

Can you put true service tree straight into a much bigger pot?

No. Even a fast-growing true service tree should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise true service tree after repotting?

Not immediately. Wait about 1 week after repotting true service tree. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.