Repotting guide

When & how to repot Incense Cedar (Calocedrus decurrens)

Also called Incense Cedar, California Incense Cedar.

More about incense cedar

About Incense Cedar

Calocedrus decurrens · also called Incense Cedar, California Incense Cedar · flowering

Incense Cedar is a tall, columnar conifer native to mountain forests of Oregon and California, instantly recognised by its narrowly cylindrical crown and aromatic, cedarwood-scented scale foliage. Remarkably adaptable, it grows in a wide range of soils and withstands both drought and moderate shade. It is the wood behind most wooden pencils and excellent as a landscape specimen.

Mature size: 15–40 m tall by 3–5 m wide in the wild; typically 10–20 m tall in cultivation gardens

Watch for — Cedar-apple rust / annosus root rot: Annosus root rot (Heterobasidion annosum) can affect mature trees, causing basal decay and eventual windthrow. Remove infected stumps promptly and treat freshly cut stumps with borax in areas where the disease is present.

How to tell incense cedar needs repotting

Repotting on a calendar is less reliable than reading the plant. For incense cedar, 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 incense cedar 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 incense cedar

Every 2–3 years; top-dress in the in-between years. Incense Cedar's growth habit — strictly columnar to narrowly conical; very symmetrical with a single straight trunk and tightly ascending lateral branches; evergreen scale-like foliage arranged in flat, fan-shaped sprays — sets the pace. Incense Cedar is a tall, columnar conifer native to mountain forests of Oregon and California, instantly recognised by its narrowly cylindrical crown and aromatic, cedarwood-scented scale foliage. Remarkably adaptable, it grows in a wide range of soils and withstands both drought and moderate shade. It is the wood behind most wooden pencils and excellent as a landscape specimen.

What size pot to step incense cedar up to

Move up exactly one pot size. A heavy incense cedar 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 incense cedar

Early spring, just as new growth restarts, is the ideal window for incense cedar. 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 incense cedar

Consider top-dressing first. If incense cedar 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 adaptable to well-drained sandy, loamy, or clay soils; ph 5.5–7.5 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 incense cedar in the same spot and light — moving and repotting at once is what makes it drop leaves.

Aftercare

Leave incense cedar 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 incense cedar

Incense Cedar wants adaptable to well-drained sandy, loamy, or clay soils; ph 5.5–7.5. Exceptionally adaptable to soil type. Prefers moist, fertile, well-drained loam but succeeds in sandy and clay soils with adequate drainage. Tolerates both mildly acid and mildly alkaline pH. Avoid permanently wet soils. Native to volcanic and granitic substrates in the Sierra Nevada and Cascade ranges. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting incense cedar — frequently asked questions

How often should you repot incense cedar?

Every 2–3 years; top-dress in the in-between years for incense cedar. Fully repot incense cedar 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 adaptable to well-drained sandy, loamy, or clay soils; ph 5.5–7.5. It is heavy and hates being moved, and a vastly oversized pot holds water against the roots and rots them.

What size pot does incense cedar need?

When is the best time of year to repot incense cedar?

Should you top-dress or fully repot incense cedar?

For a big, heavy incense cedar, 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 incense cedar after repotting?

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