Fertilising guide
How to fertilise Aglaonema Red (Aglaonema 'Red Siam')— schedule & NPK
Also called Red Siam Chinese evergreen, red aglaonema.
More about aglaonema red
About Aglaonema Red
Aglaonema 'Red Siam' · also called Red Siam Chinese evergreen, red aglaonema · tropical
Aglaonema 'Red Siam' is a striking Chinese evergreen with broad leaves splashed in pink, rose and crimson over green. A tough, slow-growing tropical that tolerates low light and irregular watering, it is one of the most forgiving coloured houseplants. Note it is toxic to pets, containing insoluble calcium oxalate crystals.
Growth habit: Upright, clumping, bushy habit that widens slowly as new shoots emerge from the base; relatively slow-growing.
Watch for — Brown leaf tips or edges: Caused by dry air, fluoride/salt buildup or over-fertilising. Use filtered water, flush the soil and ease off feeding.
What fertiliser aglaonema red actually wants — and why
Aglaonema Red 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 aglaonema red: 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 aglaonema red, 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 aglaonema red:
Feed every 4-6 weeks in spring and summer with a balanced liquid fertiliser at half strength. It is a light feeder; stop entirely in autumn and winter. Excess fertiliser causes leaf-tip burn, so under-feeding is safer than overdoing it. Treat that as every 4-6 weeks 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 aglaonema red 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 aglaonema red
Half strength is the safe default for aglaonema red — 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 aglaonema red first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the aglaonema red watering schedule.
Signs you are over-feeding aglaonema red
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for aglaonema red:
- 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 aglaonema red
- 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 aglaonema red care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of aglaonema red 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 aglaonema red
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 aglaonema red — frequently asked questions
What fertiliser does aglaonema red 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. Aglaonema Red 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 aglaonema red?
Feed every 4-6 weeks in spring and summer with a balanced liquid fertiliser at half strength. It is a light feeder; stop entirely in autumn and winter. Excess fertiliser causes leaf-tip burn, so under-feeding is safer than overdoing it. Feed every 4-6 weeks in spring and summer with a balanced liquid fertiliser at half strength. It is a light feeder; stop entirely in autumn and winter. Excess fertiliser causes leaf-tip burn, so under-feeding is safer than overdoing it. Treat that as every 4-6 weeks 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 aglaonema red?
Half strength is the safe default for aglaonema red — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding aglaonema red 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 aglaonema red 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 aglaonema red?
Flush the pot of aglaonema red 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
- Aglaonema Red care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water aglaonema red — 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 monstera
- How to fertilise pothos
- How to fertilise fiddle leaf fig
- All 2464 fertilising guides in the Growli library