Fertilising guide
How to fertilise Incense Cedar (Calocedrus decurrens)— schedule & NPK
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.
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
What fertiliser incense cedar actually wants — and why
Incense Cedar is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula.
For the language behind the three numbers on the bottle — what nitrogen, phosphorus and potassium each do — see the NPK ratio explained entry. The short version for incense cedar: match the feed to the job the plant is doing right now, not to a generic “plant food” on the shelf.
How often to feed incense cedar, and which months
Feeding only earns its keep while the plant is in active growth and can use the nutrients — pour feed into a dormant or low-light plant and it simply builds up as root-burning salt. For incense cedar:
Light feeder — an annual application of slow-release balanced fertiliser in early spring is sufficient. Avoid high-nitrogen feeds, which can promote excessive soft growth. In nutrient-poor soils, a supplemental feed in early summer may be beneficial. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
The dormant-season rule matters more than the exact interval: skip feeding entirely when incense cedar is resting. For the wider context on indoor feeding rhythms across the seasons, the houseplant fertiliser schedule walks through the year month by month.
What strength to mix for incense cedar
Half strength is the safe default for incense cedar — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
Feeding always goes onto already-damp soil, never dry roots — water incense cedar first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the incense cedar watering schedule.
Signs you are over-feeding incense cedar
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for incense cedar:
- Brown, crispy leaf tips and edges with no sign of underwatering.
- A white, crusty salt deposit on the soil surface or pot rim.
- Weak, pale, stretched new growth that flops.
- Lower leaves yellow and drop while the soil is correctly watered.
Signs you are under-feeding incense cedar
- Uniformly pale or yellow-green leaves, oldest first.
- Noticeably small new leaves and stalled growth in good light and season.
- A generally tired, lacklustre look despite correct watering and light.
If the symptoms point at watering, light or roots rather than nutrition, the full incense cedar care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of incense cedar with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Organic vs synthetic feeds for incense cedar
Organic options
A diluted seaweed or worm-casting feed, or fish emulsion if you can tolerate the smell indoors. UK: Westland or Baby Bio Organic, dilute seaweed; US: Espoma Indoor! or Neptune's Harvest fish & seaweed. Slow, gentle and hard to overdo.
Synthetic / liquid feeds
A general-purpose houseplant liquid at half strength — UK: Baby Bio, Westland Houseplant Feed or Phostrogen; US: Miracle-Gro Indoor Plant Food or Schultz. Convenient and fast-acting; the only risk is overdoing it.
Brand names are examples, not endorsements, and UK and US ranges differ — check the label’s own NPK and dilution rate, since formulations change.
Fertilising incense cedar — frequently asked questions
What fertiliser does incense cedar need?
A balanced general houseplant feed (roughly even N-P-K) is exactly right — it is grown for foliage, so steady, moderate nitrogen for healthy leaves is the goal, not a bloom or root formula. Incense Cedar is an easy, light foliage feeder — a half-strength balanced liquid feed through the growing months keeps it green without forcing weak, sappy growth.
How often should I feed incense cedar?
Light feeder — an annual application of slow-release balanced fertiliser in early spring is sufficient. Avoid high-nitrogen feeds, which can promote excessive soft growth. In nutrient-poor soils, a supplemental feed in early summer may be beneficial. Light feeder — an annual application of slow-release balanced fertiliser in early spring is sufficient. Avoid high-nitrogen feeds, which can promote excessive soft growth. In nutrient-poor soils, a supplemental feed in early summer may be beneficial. Treat that as sparingly through the growing season between spring through early autumn (roughly March to September); ease off in autumn and stop entirely in the low light of winter.
What strength of feed for incense cedar?
Half strength is the safe default for incense cedar — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding incense cedar look like?
Brown, crispy leaf tips and edges with no sign of underwatering. A white, crusty salt deposit on the soil surface or pot rim. Weak, pale, stretched new growth that flops. Lower leaves yellow and drop while the soil is correctly watered. Feeding incense cedar year-round on a fixed schedule, including dark winter months, is the most common mistake — it cannot use the nutrients in low light and the surplus simply burns the roots and crusts the soil.
Should I flush the soil of incense cedar?
Flush the pot of incense cedar with plain water until it runs freely from the base every couple of months in the feeding season — it washes out the fertiliser salts that cause brown tips.
Keep reading
- Incense Cedar care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water incense cedar — the watering schedule
- The houseplant fertiliser schedule — feeding through the year
- NPK ratio explained — what the three numbers on the bottle mean
- How to fertilise solanum crispum 'glasnevin'
- How to fertilise parthenocissus tricuspidata
- How to fertilise parthenocissus quinquefolia
- All 6887 fertilising guides in the Growli library