Fertilising guide
How to fertilise Paulownia tomentosa (Paulownia tomentosa)— schedule & NPK
Also called Foxglove Tree, Empress Tree, Princess Tree.
More about paulownia tomentosa
About Paulownia tomentosa
Paulownia tomentosa · also called Foxglove Tree, Empress Tree · flowering
An extremely fast-growing tree prized for enormous, fuzzy heart-shaped leaves and upright panicles of fragrant, foxglove-like lilac flowers that open before the foliage in spring. Often pollarded for giant decorative leaves. Note it is highly invasive in parts of North America, so check local guidance before planting.
Growth habit: Exceptionally fast-growing deciduous tree with a broad, spreading, rounded crown; can put on 2-4 m in a single year when young. Often coppiced or pollarded to control size and enlarge the leaves.
What fertiliser paulownia tomentosa actually wants — and why
Paulownia tomentosa 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 paulownia tomentosa: 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 paulownia tomentosa, 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 paulownia tomentosa:
Vigorous and rarely needs feeding in good soil. For pollarded specimens grown for foliage, a spring application of balanced or nitrogen-rich fertiliser fuels the large leaves. Mulch annually with compost. 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 paulownia tomentosa 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 paulownia tomentosa
Half strength is the safe default for paulownia tomentosa — 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 paulownia tomentosa first if the soil is dry, then apply the diluted feed. The companion question is when to water at all, covered in the paulownia tomentosa watering schedule.
Signs you are over-feeding paulownia tomentosa
Over-feeding is far more common — and more damaging — than under-feeding for most plants. The classic tells for paulownia tomentosa:
- 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 paulownia tomentosa
- 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 paulownia tomentosa care brief covers soil, humidity and the common problems for this species.
Flushing and leaching the salts
Flush the pot of paulownia tomentosa 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 paulownia tomentosa
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 paulownia tomentosa — frequently asked questions
What fertiliser does paulownia tomentosa 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. Paulownia tomentosa 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 paulownia tomentosa?
Vigorous and rarely needs feeding in good soil. For pollarded specimens grown for foliage, a spring application of balanced or nitrogen-rich fertiliser fuels the large leaves. Mulch annually with compost. Vigorous and rarely needs feeding in good soil. For pollarded specimens grown for foliage, a spring application of balanced or nitrogen-rich fertiliser fuels the large leaves. Mulch annually with compost. 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 paulownia tomentosa?
Half strength is the safe default for paulownia tomentosa — houseplant feeds are formulated strong, and the diluted dose is gentler on the roots while still ample for foliage.
What does over-feeding paulownia tomentosa 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 paulownia tomentosa 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 paulownia tomentosa?
Flush the pot of paulownia tomentosa 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
- Paulownia tomentosa care — the full brief (light, soil, humidity, problems, pet safety)
- How often to water paulownia tomentosa — 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 peace lily
- How to fertilise bird of paradise
- How to fertilise hoya
- All 5561 fertilising guides in the Growli library