Fertilising guide
How to fertilise Chinese Arborvitae (Thuja orientalis)— schedule & NPK
Also called Chinese Arborvitae, Oriental Arborvitae, Biota, Oriental Thuja.
More about chinese arborvitae
About Chinese Arborvitae
Thuja orientalis · also called Chinese Arborvitae, Oriental Arborvitae · flowering
Chinese Arborvitae (now often reclassified as Platycladus orientalis) is a versatile, drought-tolerant evergreen conifer from northeastern China and Korea. Its distinctive vertically held, fan-like foliage sprays set it apart from other arborvitaes. Highly adaptable to heat, drought, and alkaline soils, it is widely used in warm-climate hedging, topiary, and specimen planting.
Growth habit: Conical to columnar or irregular evergreen tree or large shrub; distinctive vertically-oriented, fan-shaped foliage sprays (unlike the horizontal sprays of other Thuja); scale-like, bright to mid-green leaves; bluish-green ovoid cones
What fertiliser chinese arborvitae actually wants — and why
Chinese Arborvitae 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 chinese arborvitae: 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 chinese arborvitae, 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 chinese arborvitae:
Apply a balanced slow-release fertiliser in early spring to encourage consistent growth. On fertile soils, annual feeding is not necessary. In poor or alkaline soils, an acidifying fertiliser or chelated micronutrient supplement improves foliage colour. Avoid late-season nitrogen, which delays hardening. 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 chinese arborvitae 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 chinese arborvitae
Half strength is the safe default for chinese arborvitae — 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 chinese arborvitae first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the chinese arborvitae watering schedule.
Signs you are over-feeding chinese arborvitae
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for chinese arborvitae:
- 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 chinese arborvitae
- 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 chinese arborvitae care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of chinese arborvitae 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 chinese arborvitae
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 chinese arborvitae — frequently asked questions
What fertiliser does chinese arborvitae 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. Chinese Arborvitae 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 chinese arborvitae?
Apply a balanced slow-release fertiliser in early spring to encourage consistent growth. On fertile soils, annual feeding is not necessary. In poor or alkaline soils, an acidifying fertiliser or chelated micronutrient supplement improves foliage colour. Avoid late-season nitrogen, which delays hardening. Apply a balanced slow-release fertiliser in early spring to encourage consistent growth. On fertile soils, annual feeding is not necessary. In poor or alkaline soils, an acidifying fertiliser or chelated micronutrient supplement improves foliage colour. Avoid late-season nitrogen, which delays hardening. 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 chinese arborvitae?
Half strength is the safe default for chinese arborvitae — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding chinese arborvitae 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 chinese arborvitae 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 chinese arborvitae?
Flush the pot of chinese arborvitae 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
- Chinese Arborvitae care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water chinese arborvitae — 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 hydrocharis morsus-ranae
- How to fertilise stratiotes aloides
- How to fertilise ranunculus aquatilis
- All 6887 fertilising guides in the Growli library