Germinated a few Norfolk Island hibiscus trees lagunaria Petersonii

[happypalms]

Purchased a few Norfolk Island hibiscus seeds. Trying my luck at some different tree species as a good way to get some rare trees in the garden. I have never seen the plants for sale so seeds are the next best option.  Not sure how they will grow time will tell but they seemed pretty easy to germinate. The flower was what first attracted me to the plant also coming from Norfolk Island helped.

[Jonathan]

I've got half a dozen in the ground that I grew from seed a few years back. They grow pretty quickly and are tough as nails. I reckon they'll be rockets in your climate Richard.

[happypalms]

1 hour ago, Jonathan said:

I've got half a dozen in the ground that I grew from seed a few years back. They grow pretty quickly and are tough as nails. I reckon they'll be rockets in your climate Richard.

Well that’s good news to me they will take the cold then and fast growing thanks Jonathan.

[Than]

On 10/19/2024 at 1:02 PM, Jonathan said:

I've got half a dozen in the ground that I grew from seed a few years back. They grow pretty quickly and are tough as nails. I reckon they'll be rockets in your climate Richard.

I am thinking of adding one in my garden. Do you happen to know if they are safe near foundations and retention walls? Not too close, about 6m / 20 ft. I cannot find much info about their root destructiveness online.

[Jonathan]

30 minutes ago, Than said:

I am thinking of adding one in my garden. Do you happen to know if they are safe near foundations and retention walls? Not too close, about 6m / 20 ft. I cannot find much info about their root destructiveness online.

I've never noticed any problems with them in that regard, but also haven't been paying particular attention to it. There's a few big ones around here I'll have a closer look and report back.

[happypalms]

17 minutes ago, Jonathan said:

I've never noticed any problems with them in that regard, but also haven't been paying particular attention to it. There's a few big ones around here I'll have a closer look and report back.

Seeds please 🙏 Jonathan! 

[Jonathan]

18 minutes ago, happypalms said:

Seeds please 🙏 Jonathan! 

Yep...I'll check my trees today. They should be ready in the next couple of months.

[Than]

8 hours ago, Jonathan said:

I've never noticed any problems with them in that regard, but also haven't been paying particular attention to it. There's a few big ones around here I'll have a closer look and report back.

Please do. Thanks a lot

[Rivera]

On 1/16/2026 at 12:23 PM, Than said:

I am thinking of adding one in my garden. Do you happen to know if they are safe near foundations and retention walls? Not too close, about 6m / 20 ft. I cannot find much info about their root destructiveness online.

At that distance, I wouldn't worry about these. The evidence you'll get one way or another will be anecdotal, but these are common street trees in my district of San Francisco and I've also seen them planted in close proximity to homes (closer than you're considering).

I guess any dicot tree carries some of these risks in the long term, but their ultimate size isn't too big.

[Than]

57 minutes ago, Rivera said:

these are common street trees in my district of San Francisco

That's positive because the amount of rain in SF is very close to that here and I have read that these trees easily suffer from root rot. It's one of the very few options for a fast growing evergreen tree where I live. I need it as canopy.

[Jonathan]

2 hours ago, Than said:

That's positive because the amount of rain in SF is very close to that here and I have read that these trees easily suffer from root rot. It's one of the very few options for a fast growing evergreen tree where I live. I need it as canopy.

I can't see too many issues with roots in local trees, but they can get pretty big, so I'd still be cautious. I've got 3 growing in a very wet part of our property on clay, no root rot problems, they're tough trees.

Also, Lagunaria seed pods are full of itchy hairs that drop out and blow around in the wind, could be very irritating on a smaller property. 

My choice would be Banksia integrifolia though, as I mentioned in the other thread, a nicer tree all round.

[Than]

10 hours ago, Jonathan said:

I can't see too many issues with roots in local trees, but they can get pretty big, so I'd still be cautious. I've got 3 growing in a very wet part of our property on clay, no root rot problems, they're tough trees.

Also, Lagunaria seed pods are full of itchy hairs that drop out and blow around in the wind, could be very irritating on a smaller property. 

My choice would be Banksia integrifolia though, as I mentioned in the other thread, a nicer tree all round.

Nice, thank you Jonathan! I was not familiar with Banksia, sounds like a good choice indeed and thankfully it is on sale in some EU nurseries. It doesn't grow as fast as Lagunaria though, right? I'm kind of desperate for fast canopy.

Are Lagunaria roots risky for foundations and walls? Should I plant far if I go for this tree in the end?

[Jonathan]

1 hour ago, Than said:

Nice, thank you Jonathan! I was not familiar with Banksia, sounds like a good choice indeed and thankfully it is on sale in some EU nurseries. It doesn't grow as fast as Lagunaria though, right? I'm kind of desperate for fast canopy.

Are Lagunaria roots risky for foundations and walls? Should I plant far if I go for this tree in the end?

I'd plant further back for safety.

Banksia integrifolia is faster than lagunaria in my climate, considerably faster!

[Than]

11 minutes ago, Jonathan said:

Banksia integrifolia is faster than lagunaria in my climate, considerably faster!

That's interesting! Online sources mostly say it grows by about 10 inches per year, which I consider kind of slow. Ι guess your soil is acidic and that helps.

Last question if you don't mind: how big and wide do Banksias normally grow in a garden setting? 

[Jonathan]

2 hours ago, Than said:

That's interesting! Online sources mostly say it grows by about 10 inches per year, which I consider kind of slow. Ι guess your soil is acidic and that helps.

Last question if you don't mind: how big and wide do Banksias normally grow in a garden setting? 

B integrifolia grows at about 1m per year down here on acid clay with zero additional water, Lagunaria can probably achieve a similar rate but needs heaps more water to get moving, at least in my climate. 10m x 5m wide probably would be a good sized integrifolia in cultivation, but they can get up to 25m in habitat. 

Grevillea robusta would be worth considering too.

[Than]

2 hours ago, Jonathan said:

B integrifolia grows at about 1m per year down here on acid clay with zero additional water, Lagunaria can probably achieve a similar rate but needs heaps more water to get moving, at least in my climate. 10m x 5m wide probably would be a good sized integrifolia in cultivation, but they can get up to 25m in habitat. 

Grevillea robusta would be worth considering too.

Thanks a lot. Unfortunately my soil is alkaline. My situation is kinda hopeless 😅

I need a tree that can tolerate alkaline soil (I will amend a bit though and perhaps create a bed), can take light frost and heatwaves and grows fast staying evergreen. Must be safe at around 5m from retention walls. I think my only options are Lagunaria and Brachychiton populneus. Apparently both can tolerate alkalinity even if they don't prefer it. Schinus molle is another fast option but I find conflicting info about the root destructiveness.

I wish carob trees weren't so slow..

[Jonathan]

7 hours ago, Than said:

Thanks a lot. Unfortunately my soil is alkaline. My situation is kinda hopeless 😅

I need a tree that can tolerate alkaline soil (I will amend a bit though and perhaps create a bed), can take light frost and heatwaves and grows fast staying evergreen. Must be safe at around 5m from retention walls. I think my only options are Lagunaria and Brachychiton populneus. Apparently both can tolerate alkalinity even if they don't prefer it. Schinus molle is another fast option but I find conflicting info about the root destructiveness.

I wish carob trees weren't so slow..

 

According to the internet alkaline soil is no problem for this species...I would be inclined to give it a go. I think you may be over-thinking it!

11 hours ago, Than said:

That's interesting! Online sources mostly say it grows by about 10 inches per year, which I consider kind of slow. Ι guess your soil is acidic and that helps.

Last question if you don't mind: how big and wide do Banksias normally grow in a garden setting? 

B integrifolia grows at about 1m per year down here on acid clay with zero additional water, Lagunaria can probably achieve a similar rate but needs heaps more water to get moving, at least in my climate. 10m x 5m wide probably would be a good sized integrifolia in cultivation, but they can get up to 25m in habitat. 

Grevillea robusta would be worth considering too.

[Than]

5 minutes ago, Jonathan said:

 

According to the internet alkaline soil is no problem for this species...I would be inclined to give it a go. I think you may be over-thinking it!

B integrifolia grows at about 1m per year down here on acid clay with zero additional water, Lagunaria can probably achieve a similar rate but needs heaps more water to get moving, at least in my climate. 10m x 5m wide probably would be a good sized integrifolia in cultivation, but they can get up to 25m in habitat. 

Grevillea robusta would be worth considering too.

You have convinced me! I'll get a Banksia, already found one at a European nursery. Lagunarias are much easier to obtain, they are sold by all major Greek nurseries at reasonable prices. Grevillea is very common here, also as a street tree, but I also excluded it because it wants acidic soil apparently. 

[Jonathan]

Just now, Than said:

You have convinced me! I'll get a Banksia, already found one at a European nursery. Lagunarias are much easier to obtain, they are sold by all major Greek nurseries at reasonable prices. Grevillea is very common here, also as a street tree, but I also excluded it because it wants acidic soil apparently. 

Haha, I'm a persistent bugger! 

Hope it works out for you.

[happypalms]

1 hour ago, Jonathan said:

Haha, I'm a persistent bugger! 

Hope it works out for you.

I have been warned of the weed potential of this tree, so with caution it shall be watched carefully, especially in my sandy soil!