Silky oak
Grevillea robusta
Also called Grevillea, Australian silver oak and Southern silky oak
Houseplant · Trees & big statementsLOW-PHOSPHORUS FEED ONLY, like every Australian native — ordinary houseplant food scorches the roots. Grown from seed it is a fast, forgiving foliage plant; it will never flower indoors and it grows into a forest tree if let.
Care at a glance
- Ease
- Easy
- Water
- Once a weekDrench and drain — water the whole surface until it runs from the holes.
- Light
- Bright, with several hours of direct sun
- Feed
- Every 30 days
- Humidity
- Low
- Hardiness
- Tender — no frost at all RHS H2, to 1°C
- Size
- 2 m tall · 1 m across
- Lifecycle
- Tree
- Origin
- Eastern Australia
Is it safe for pets and people?
No animal-poison authority lists this plant either way.
Nobody has checked this one against a source for us yet, so treat it as unknown rather than safe.
Neither authority names Grevillea. That is an absence and not a clean bill — and the foliage causes contact dermatitis in some people, so wear gloves to prune it.
Checked against ASPCA and RHS on 2026-09-22. Where a source says nothing, we say nothing.
A guide, not veterinary or medical advice. If a pet or a person has eaten a plant and you are worried, call your vet or doctor now — don’t wait for signs to appear. Spotted a mistake? Tell us.
First signs of trouble
- Leaf tips blackening within weeks of being fed, on a plant that was growing well. Australian natives evolved on soil with almost no phosphorus; use a native or low-phosphorus feed, or none at all.Phosphorus burn · disorder
- A metre of growth in a season and a bare lower stem. It is a forest tree — cut the top out hard each spring and expect to start again from seed every few years.Outgrowing the room · disorder