PlantFiles: Silk Oak, Silky Oak
Grevillea robusta

Hi, I live north of san francisco , and I have to tell you this is a messy, ugly tree. I just had it cut down today! it was 45' tall and just crapped all over my deck, and my neighbors deck, all year round. It drops leaves, it drops flowers, it drops seeds. And it almost never looses all its seeds, so, The tree looks so shoddy. I have lived at my house for 6 years and I wanted to cut it down after the first year. I truly despised this tree. And now its gone, good riddens. Please, think twice if you plan to add this tree to your property. Take a look at this tree before you buy. Or, if you buy this tree, but a rake, you will need it.

I planted this tree about 4 years ago in my backyard. I live in Zephyrhills,FL ,33541- zone 9A (?). Our winters have dropped into the high 20's and this tree has survived. The leaves are fern-like and very attractive. My only disappointment is that the tree has not yet bloomed ( which is why I planted it in the first place to attract birds, butterflies,and hummingbirds) . Could anyone give me any ideas as to why it has't bloomed yet?? I planted the tree in front of some oak trees which minimally shade the tree during a small part of the day.The tree gets mostly sun to minimal part shade . .I would appreciate any feedback.
Thanks, Reesieo

I have not grown this tree. Silk Oak, Silky Oak (Grevillea robusta) which is a native Ausralian tree has become naturalized in Florida, the Hawaiian Islands and Puerto Rico.

My soil is mostly decomposed granite but the trees have no trouble growing in it. The seeds actually seem to prefer this tough soil. I spend a lot of time pulling out seedlings all over the yard; yes, they are that prolific!

I trim off the bottom branches and that makes the trees great for shade.

I've also noticed that the roots seem to be very touchy about being disturbed during transplants. My success rate is very low and seems to be mainly the plants where I have a huge dirt ball around the roots.

I love this tree, but . . . my silk oak is tall and spindly - looks like a Charlie Brown Christmas Tree! The top 8-10 feet has very few branches. Should I top the tree?

My rear yard is a south facing canyon slope and is planted in citrus at the upper part near the house. About a year ago, to my amazement, I saw bright yellow-orange patches through the citrus trees that turned out to be the blossoms of a 20 Ft. tall Grevillia. The tree is a true volunteer and to my knowledge there are no other nearby specimens. I can't be sure how long it has been there, but not more than two or three years. I guess I'll let it grow since it seems to be so happy in its chosen home, which is also mine. If it keeps growing at the present rate it'll be a good climbing tree for my grandson.

Extremely common landscaping tree here in Southern California.. a beautiful tree, but somewhat overused in our suburbs. This tree has the down side of having very brittle wood, and branches falling off for apparently no reason whatsoever are not uncommon events. It is heavy wood, too, though, so a lot of damage can occur when one of these branches crashes on your car or house. They seem to like to 'top' these trees here, perhaps for that reason.

I live in San Juan Capistrano, CA and finally yesterday found out from a tree expert hired to trim back some of our other trees-that the 50ft tree growing in the middle of the yard is called a Silk Oak. The tree popped up in the middle of our yard only four years ago and is growing like a weed. We thought it was just some cute little shrub at first so we let it grow. The second year tons of yellow & orange flowers with a sticky nectar covered the trees. We have many tropical birds that come to this area in the spring and they just went wild for the nectar-we never had so many birds in our back yard. We have no idea where the seed for the tree came from as there are no silk oak trees in our general area. Lucky for us it grew in the middle of the yard in an area away from other trees-as it will probably reach 100ft in the next few years!

The report that this tree is hardy in 9a is questionable. They used to grow in Bartow until we had one of our occasional hard freezes, but not one survived that I'm aware of.

Reciently had this plant placed in my back yard. think it is beautiful, however allot of the leaves and some of the branches fell off this week. Bark is still green and healthy but concerned that the tree may be dieing. Is this a normal seasonal shedding or should I be concerned?

I live in Houston, texas & have grown a silk oak from a so called house plant that was 3 feet tall in spring of 1991. It has been topped 3 times since by the power company, ( I did not know it would become a tree) It is now appx 25 feet tall & 20 feet wide. It has bloomed 6 years in a row..Last summer I collected some seeds & did not plant them until the end of october. I babied the seeds all through the winter months on an enclosed patio & would bring them in the house on really cold nights. I have 22 gallon pots of silk oaks now that are 2 feet tall. I have planted seeds this month & will plant more in august..The tree is so gorgeous & would be more so if it didn't keep getting mutilated.

This tree is quite rare in the wild. Its timber was valued because of its distinctive smooth texture. It is spectacular in flower, especially in numbers, for example, in an avenue. Nectar eating birds flock to it.

I planted the seed of a silk oak some 5 - 7 years ago; at first in a pot, and then when the sapling was about 3 ft. tall, it was planted in the ground. Since then (3+ yrs.) the tree has grown to some 30 feet but has yet to bloom. In this area (central Calif. coast) the tree is very popular and is used as a street tree as well as in many yards.

An spectacular tree when blooming, for some reason it hardly survives the climate of Rio de Janeiro, being planted more to the south of Brazil, where the heat is more moderate and the winters are colder. It´s commonly used as wind breaker.

Grevillea robusta is the largest member of the Grevillea family. It is a native of eastern Australia where its common name is "Silky Oak". It attains a height of 40 metres (130 feet) in the tropics; in temperate regions it grows to about half that.

The tree is usually evergreen but may be deciduous in cold areas. The leaves are the size of an adult's spread hand, bipinnate, similar in construction to the fronds of a tree fern. I have read books that suggest the flowers are 10cm (4") long, but the trees around Adelaide, South Australia (Mediterranean climate) bear flowers 30cm (1ft) long on average.

These beautiful brilliant yellow-orange flowers bear prodigious amounts of nectar which may be collected by briskly shaking the flowers in a bucket. If you suck on the flower of any grevillea you get a tasty few drops of nectar. The seeds are dark brown and the size of a pea. The tree self-seeds readily in our area in the Adelaide Hills (1100 ft altitude near Adelaide.)

The roots are intrusive so the tree needs to be well away from sewage pipes. From my experience the roots are not particularly hard on foundations as long as the tree is 10m (33 ft) or more from them.