Paulownia tomentosa (Foxglove Tree) care

Light

Most houseplants will scorch where paulownia tomentosa thrives. Give it the windowsill you'd otherwise leave empty because everything else burned there. Full sun is essential for flowering and the strongest growth. In shade it becomes sparse and rarely blooms. Shelter from strong wind, which shreds the large soft leaves. A plant moved abruptly from low light to direct sun bleaches in 48 hours — always acclimatise over a week.

Watering

Aim for water weekly while establishing in the first two seasons, then rely largely on rainfall for paulownia tomentosa, but treat that as a starting point rather than a rule. A south-facing summer windowsill will dry the pot twice as fast as a north-facing winter room. Lift the pot; if it feels noticeably lighter than it did wet, water it. Young trees need steady moisture to fuel their rapid growth; established trees are drought-tolerant but appreciate a deep soak in extended dry spells. Avoid permanently wet soil.

Soil and pot

Paulownia tomentosa grows best in deep, fertile, free-draining loam. Tolerates a wide pH range and many soils, but grows fastest in rich, moist, well-drained ground. Dislikes heavy waterlogged clay and shallow, drought-prone sites. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Paulownia tomentosa sits happiest at around Ambient outdoor humidity and -23 to 38°C (-10 to 100°F). An outdoor tree with no special humidity requirement; performs well in warm-temperate climates with reliable summer warmth to ripen its growth. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed paulownia tomentosa sparingly. 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. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on paulownia tomentosa in the Growli community. Each is annotated with the most common cause so you know where to start.

• Frost-killed flower buds — Flower buds form in autumn and overwinter on bare stems; a hard frost or cold spring often destroys them, so blooming is unreliable in colder areas. The tree itself usually survives.
• Invasiveness — Prolific wind-blown seed makes it a recognised invasive species across much of the eastern and southern US; deadhead spent flowers or pollard before seeding, and check regional restrictions.
• Wind-shredded leaves — The huge, soft leaves tear easily in exposed sites and look tatty by late summer. Plant in a sheltered position.
• Suckering and brittle wood — Vigorous roots can throw up suckers, and the soft, fast-grown timber breaks readily in storms. Remove suckers promptly and prune for sound structure.

Propagation

Easily raised from its abundant fine seed sown on the surface in warm conditions; also propagated from root cuttings taken in winter and semi-ripe cuttings. Coppice stumps regenerate freely. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Paulownia tomentosa is mildly toxic to pets. Paulownia tomentosa is not individually listed by the ASPCA, and published sources conflict on its pet safety; the seeds and leaves may cause gastrointestinal upset if eaten. Treat with caution and verify with a vet before assuming it is safe around pets. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Paulownia tomentosa deep-dive guides

Every aspect of paulownia tomentosa care, each with its own calibrated guide:

• Paulownia tomentosa watering schedule
• Paulownia tomentosa light requirements
• Best soil mix for paulownia tomentosa
• Paulownia tomentosa fertilizing guide
• When to repot paulownia tomentosa
• How to propagate paulownia tomentosa
• Paulownia tomentosa growth rate & size
• Paulownia tomentosa cold hardiness
• Paulownia tomentosa temperature & humidity
• Is paulownia tomentosa toxic to cats & dogs?
• Is paulownia tomentosa toxic to cats?
• Is paulownia tomentosa toxic to dogs?
• Getting paulownia tomentosa to bloom

Featured in these plant shortlists

Paulownia tomentosa qualifies for 6 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best drought-tolerant houseplants — Houseplants that prefer to dry out — forgiving of forgotten watering and ideal for travel or busy weeks.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best houseplants for full sun — Houseplants that want direct sun — the species for a hot south or west-facing windowsill where shade-lovers scorch.
• Best houseplants for a cool room — Houseplants that tolerate cool conditions down to about 10°C — for an unheated spare room, hallway, porch or a home kept cool.
• Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
• Best fragrant houseplants — Indoor plants with scented flowers or aromatic foliage — greenery you can smell, selected from our care library.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Paulownia tomentosa is also known as Foxglove Tree, Empress Tree, and Princess Tree.

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