Fertilising guide
How to fertilise Atlas Cedar (Cedrus atlantica)— schedule & NPK
Also called Atlas Cedar, Blue Atlas Cedar.
More about atlas cedar
About Atlas Cedar
Cedrus atlantica · also called Atlas Cedar, Blue Atlas Cedar · flowering
Atlas Cedar is a stately North African conifer from the Atlas Mountains of Morocco and Algeria, celebrated for its distinctive blue-green to silver-blue foliage and broadly spreading, irregular crown with age. Hardy and drought-tolerant once established, it is a classic specimen tree for large gardens across USDA zones 6–9. The weeping cultivar 'Glauca Pendula' is widely grown.
Growth habit: Broadly pyramidal when young, becoming flat-topped and wide-spreading with great age. Branches are horizontal; branchlet tips are slightly ascending (unlike the drooping tips of Cedrus deodara). Needles are blue-green to silver-blue in tufts on short spurs. Slow-growing in maturity.
What fertiliser atlas cedar actually wants — and why
Atlas 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 atlas 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 atlas 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 atlas cedar:
Established trees rarely need fertilising on suitable soils. Young trees benefit from a slow-release balanced fertiliser in early spring for 2–3 years after planting. Avoid high-nitrogen feeds, which reduce drought tolerance and blue foliage colour. 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 atlas 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 atlas cedar
Half strength is the safe default for atlas 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 atlas cedar first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the atlas cedar watering schedule.
Signs you are over-feeding atlas cedar
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for atlas 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 atlas 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 atlas cedar care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of atlas 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 atlas 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 atlas cedar — frequently asked questions
What fertiliser does atlas 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. Atlas 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 atlas cedar?
Established trees rarely need fertilising on suitable soils. Young trees benefit from a slow-release balanced fertiliser in early spring for 2–3 years after planting. Avoid high-nitrogen feeds, which reduce drought tolerance and blue foliage colour. Established trees rarely need fertilising on suitable soils. Young trees benefit from a slow-release balanced fertiliser in early spring for 2–3 years after planting. Avoid high-nitrogen feeds, which reduce drought tolerance and blue foliage colour. 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 atlas cedar?
Half strength is the safe default for atlas cedar — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding atlas 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 atlas 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 atlas cedar?
Flush the pot of atlas 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
- Atlas Cedar care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water atlas 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 daphne laureola
- How to fertilise clethra barbinervis
- How to fertilise physocarpus opulifolius 'center glow'
- All 6887 fertilising guides in the Growli library