Repotting guide

When & how to repot Giant Dogwood (Cornus controversa)

Also called Giant Dogwood, Table Dogwood, Wedding Cake Tree.

More about giant dogwood

About Giant Dogwood

Cornus controversa · also called Giant Dogwood, Table Dogwood · flowering

Giant dogwood is a large, architecturally striking deciduous tree from East Asia, producing tiered horizontal branches like stacked wedding cake layers. In late spring, flat-topped clusters of small white flowers cover each tier, followed by blue-black fruit and burgundy autumn color. Far larger than other dogwoods, it demands space but is a bold, structural specimen tree of the first order.

Mature size: 10–15 m tall, 8–12 m wide

Watch for — Waterlogging and root rot: Poorly drained soils cause Phytophthora root rot, gradual decline, and dieback; ensure excellent drainage before planting, particularly in clay-heavy gardens, and avoid low-lying frost pockets.

How to tell giant dogwood needs repotting

Repotting on a calendar is less reliable than reading the plant. For giant dogwood, watch for these signs:

Thick roots out of the drainage holes, or circling the surface and lifting the plant.
The pot dries out unusually fast and giant dogwood wilts between waterings it used to shrug off.
The plant is visibly top-heavy and tips over easily.
Stalled growth and small new leaves over a full season — though with a big specimen, top-dressing is often the better first response before a full repot.

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 giant dogwood

Every 2–3 years; top-dress in the in-between years. Giant Dogwood's growth habit — large, broadly spreading deciduous tree with a strongly architectural, tiered horizontal branching pattern. branches radiate outward in distinct stacked layers, creating the 'wedding cake' silhouette that makes this one of the most structurally distinctive of all garden trees. — sets the pace. Giant dogwood is a large, architecturally striking deciduous tree from East Asia, producing tiered horizontal branches like stacked wedding cake layers. In late spring, flat-topped clusters of small white flowers cover each tier, followed by blue-black fruit and burgundy autumn color. Far larger than other dogwoods, it demands space but is a bold, structural specimen tree of the first order.

What size pot to step giant dogwood up to

Move up exactly one pot size. A heavy giant dogwood dropped into a vastly bigger pot sits in a reservoir of wet soil its roots cannot reach, which rots them and destabilises the plant. In the years between repots, lift off and replace the top 3–5 cm of soil (top-dressing) instead — it refreshes nutrients without the shock of a full repot.

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 giant dogwood

Early spring, just as new growth restarts, is the ideal window for giant dogwood. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting giant dogwood

Consider top-dressing first. If giant dogwood is not badly root-bound, scrape off and replace the top 3–5 cm of soil instead — far less shock for a big plant that hates moving.
Get help and one size up. For a full repot, choose a pot just one size larger. A heavy plant needs two people and a stable, free-draining pot.
Ease it out on its side. Lay the plant down, slide the pot off, and gently loosen the outer roots. Do not bare-root a mature specimen.
Repot at the same depth. Add fresh moist, fertile, well-drained acidic to neutral loam beneath and around the rootball, keeping the original soil line. Firm it so the trunk is stable and upright.
Water and leave it put. Water thoroughly, then leave giant dogwood in the same spot and light — moving and repotting at once is what makes it drop leaves.

Aftercare

Leave giant dogwood in exactly the same spot and light it was in before — moving and repotting at the same time is what makes a big specimen drop leaves. Water it in well, then let the top of the soil dry before watering again so the larger volume of fresh soil does not stay sodden. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for giant dogwood

Giant Dogwood wants moist, fertile, well-drained acidic to neutral loam. Prefers slightly acidic to neutral pH 5.5–7.0, rich in organic matter. Adapts to a wider range of soil types than Cornus florida but dislikes waterlogged clay or thin chalky soil. Plant in well-prepared, deeply cultivated ground to support vigorous root development. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting giant dogwood — frequently asked questions

How often should you repot giant dogwood?

Every 2–3 years; top-dress in the in-between years for giant dogwood. Fully repot giant dogwood only every 2–3 years; in the in-between years just top-dress the top 3–5 cm of soil. Step up one pot size in spring with moist, fertile, well-drained acidic to neutral loam. It is heavy and hates being moved, and a vastly oversized pot holds water against the roots and rots them.

What size pot does giant dogwood need?

When is the best time of year to repot giant dogwood?

Should you top-dress or fully repot giant dogwood?

For a big, heavy giant dogwood, top-dressing — replacing the top 3–5 cm of soil — is the gentler option most years, with a full repot only every 2–3 years. A mature specimen sulks and drops leaves when fully repotted, so do it as rarely as the roots allow.

Should you fertilise giant dogwood after repotting?

Not immediately. Wait about 4 weeks after repotting giant dogwood. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.