Arenga westerhoutii: the new leaf from above

[pietropuccio]

Arenga westerhoutii: the new leaf from above

 

 

[Phoenikakias]

Which sp is more cool tolerant according to your experience, pinnata or westerhoutii?

[Merlyn]

@pietropuccio that's a great looking palm, can we see more?  I have a single one that sprouted out of an RPS order, eventually it'll get big enough to plant...maybe... 

As far as hardiness goes, I found limited info.  Kinzyjr's sheet has only one report for Westerhoutii, from the Leu Gardens 2009 extended 29F freeze.  Eric reported minor leaf damage, categorized there as "up to 20%."  This is less than their big Pinnata.  My recollection is that they are all under at least some canopy.  This is the bigger one.  It does have some taller palms around it, but I don't know what it looked like 15 years ago.

This is a newer one, I don't think it's seen any serious freezes yet:

I have two large Pinnata (10+ feet tall and starting to trunk) and one smaller one in the ground.  They have all taken serious damage or defoliation with frosts in the 26-30F range, but so far have regrown okay.  It would be great if Westerhoutii is a couple of degrees hardier...

[Phoenikakias]

I  had one several years ago (alas it is monocarpic). It withstood settled snow and -1 to -2 C (so it survived also icy conditions) as juvenile. Also faster grower in pot than pinnata.

[pietropuccio]

14 hours ago, Phoenikakias said:

Which sp is more cool tolerant according to your experience, pinnata or westerhoutii?

Hi,

in my weather condition they behave the same way, no sign of suffering.

 

[pietropuccio]

10 hours ago, Merlyn said:

@pietropuccio that's a great looking palm, can we see more?  I have a single one that sprouted out of an RPS order, eventually it'll get big enough to plant...maybe... 

Many thanks!
The plant is in such a position that it is difficult to take a photo of the whole plant, that's why I took a photo from above 🙂

[John hovancsek]

This kinda reminds me of that first pic . I don’t have a name on it but it was a gift to me years ago and didn’t think it would cluster

[TropicsEnjoyer]

Hi. Would it be worth trying to grow one of these in 9b st augustine? Or should I just stick to engleri. And how fast do seedlings grow from seed?¿

[pietropuccio]

Hi, I think it's worth a try. My palm is 20 years old, with a trunk about 60 cm tall, 5 m long leaves, and 1.20 cm long leaflets. Its growth rate, in my growing conditions, is significantly slower than that of the Arenga pinnata.

[TropicsEnjoyer]

14 hours ago, pietropuccio said:

Hi, I think it's worth a try. My palm is 20 years old, with a trunk about 60 cm tall, 5 m long leaves, and 1.20 cm long leaflets. Its growth rate, in my growing conditions, is significantly slower than that of the Arenga pinnata.

Thanks for the reply. I might have to change plans though, because I did not find any seeds near the palm. However, I did get some engleri and a single undulatifolia seed. You have any tips on how to germinate and maintain the seedlings?

[Merlyn]

On 7/10/2025 at 11:40 AM, TropicsEnjoyer said:

Hi. Would it be worth trying to grow one of these in 9b st augustine? Or should I just stick to engleri. And how fast do seedlings grow from seed?¿

I have one here in 9B that I grew from RPS seed.  It isn't a fast grower, but reasonable.  If I recall correctly it is similar to Arenga Pinnata in appearance, growth speed and hardiness.  I will get a photo for you.  Arenga Engleri is definitely hardier, but I have three barely trunking Pinnata that have been defoliated a few times with frosts at 27-30 and they just keep growing right back.

[Merlyn]

I will say that Undulatifolia is a wimp, though.  I grew some from RPS seed, and they turned to mush with a 34F frost.  Even the one under canopy and near the house died.  In my limited experience Undulatifolia is not even a 10A palm.

[TropicsEnjoyer]

24 minutes ago, Merlyn said:

I will say that Undulatifolia is a wimp, though.  I grew some from RPS seed, and they turned to mush with a 34F frost.  Even the one under canopy and near the house died.  In my limited experience Undulatifolia is not even a 10A palm.

Yikes. I trust your experience a lot. But nevertheless I will attempt to grow the seed. I wouldn’t mind having an exotic indoor palm if it can’t stay outside during winter.

[pietropuccio]

19 hours ago, TropicsEnjoyer said:

Thanks for the reply. I might have to change plans though, because I did not find any seeds near the palm. However, I did get some engleri and a single undulatifolia seed. You have any tips on how to germinate and maintain the seedlings?

Some information on growing Arenga engleri and Arenga undulatifolia:

https://www.monaconatureencyclopedia.com/arenga-engleri/?lang=en 

https://www.monaconatureencyclopedia.com/arenga-undulatifolia/?lang=en