Hawai'i rainfall tolerance: Encephalartos ituriensis, transvenosus and woodii hybrid?

[Morabeza 36]

Aloha,

I've been growing some Encephalartos seedlings under cover for a few years and now I'm getting curious about moving them out to full rain exposure, but I'm in one of the highest rainfall zones of the Big Island and don't want to lose them to rot. I'm at 660m (2060') asl, 6350mm (250") rainfall per year, winter nights 10-13C (50-55F), summer nights 15-19C (60-66F).

The cycads in question are: Encephalartos transvenosus, Encephalartos ituriensis. and Encephalartos [woodii x (woodi x transvenosus)]. They are in tall band pots, and very over-grown (should have been moved up to 5 gallon pots 3 years ago). I will be potting them up into nearly pure pumice with probably 5-10% peat mixed in.

Any advice on rain tolerance would be welcome. I am familiar with the wonderful cycad plantings at Pana'ewa Zoo but I am in a place with double the rainfall and lower temperatures. I am sure the temperatures will be no issue for them, but lowered temperatures combined with high rainfall can complicate the equation. It's not unusual for it to rain heavily for 2-3 weeks with no breaks.

A web search on the habitats:

E. ituriensis 1900mm (75") rain per year, 1100-1200m asl

E. transvenosus 1500+mm (59") rain per year, 600-1000m asl

E. woodii (oNgoye Forest) 391mm per year, ~500m asl

Edited January 17, 2020 by Morabeza

[Tracy 4,605]

14 hours ago, Morabeza said:

I will be potting them up into nearly pure pumice with probably 5-10% peat mixed in.

Coming from a spot with very little rainfall I can't answer how they will tolerate as much rain as you get but I do think your thoughts on planting them in the nearly pure pumice mix will give them a much better shot at tolerating all that rain.  I have the opposite problem, having to supplement water in my growing zone.  Given that you have two readily accessible species and one not so readily accessible E (trans-wood x woodii), I would be inclined to pull the transvenosus and the ituriensis out first and see how they perform.  Based on what you are describing I would still pot up the transwood x woodii even though you aren't moving it out.

 

14 hours ago, Morabeza said:

Encephalartos [woodii x (woodi x transvenosus)

 Must be an Encephalartos (transvenosus x woodii) x woodii, since the first is the mother plant and second is the pollinator.  No female woodii cones so it can't be woodii x transvenosus.   I wish you success and you will have to share the results you have with the transition on these.

[Morabeza 36]

7 hours ago, Tracy said:

Must be an Encephalartos (transvenosus x woodii) x woodii, since the first is the mother plant and second is the pollinator.  No female woodii cones so it can't be woodii x transvenosus.   I wish you success and you will have to share the results you have with the transition on these.

Ah yes, thank you for catching my mistake and for the advice

[GeneAZ 168]

The transvenosus x woodii should do well if you plant it on a mound about 18 inches elevated and use larger diameter lava for the mound (+/- half inch size).  Transvenosus comes from a locale where it's almost daily bathed in mists and it does get rather a lot of rain, but with flawless drainage from the terrain.  With woodii blood in the mix from the male contribution, and mom had to be transvenosus, I'm pretty sure just elevating the planting bed would be the only modification you'd need to make. 

Your humidity coupled with heavy rains does make me worry a bit about the crown-rot risk on this hybrid.  I don't have a solution for that, short of building a transparent roof on posts like they do with succulents in this situation.

[Merlyn 1,108]

I have Ituriensis, Whitelockii and Laurentianus in the ground here in Orlando FL.  We get about 60" of rain per year, mostly in the summer months with 8-10" per month.  These three do "ok" in sandy soil here, but seem to appreciate some extra water from my dripline setup.  I think I have a 0.5gph dripper on each one running for 30 minutes.  They are all in full sun here, I'm guessing you'd need to do the same there.

250" is a lot of rain, especially if it's daily.  Our rain pattern tends to be warm and sunny except for 2-3pm.  We get a torrential downpour for 20 minutes and then it clears up again.  I suspect they may be able to tolerate lots of rain if they are in very well draining soil and get a lot of sun.  Habitat pictures of Whitelockii seem to show them on rocky hillsides near a river, so

I don't know anything about Transvenosus or Woodii habitat, so I can't make any semi-rational comments there.

[Morabeza 36]

12 hours ago, GeneAZ said:

The transvenosus x woodii should do well if you plant it on a mound about 18 inches elevated and use larger diameter lava for the mound (+/- half inch size).  Transvenosus comes from a locale where it's almost daily bathed in mists and it does get rather a lot of rain, but with flawless drainage from the terrain.  With woodii blood in the mix from the male contribution, and mom had to be transvenosus, I'm pretty sure just elevating the planting bed would be the only modification you'd need to make. 

Your humidity coupled with heavy rains does make me worry a bit about the crown-rot risk on this hybrid.  I don't have a solution for that, short of building a transparent roof on posts like they do with succulents in this situation.

Thank you for your suggestions. I feel that the transvenosus is likeliest to handle the rain. I'm probably going to err on the side of caution with the woodii hybrid and keep it under cover; maybe in 10 years it will make a pup and I can experiment with that.

8 hours ago, Merlyn2220 said:

I have Ituriensis, Whitelockii and Laurentianus in the ground here in Orlando FL.  We get about 60" of rain per year, mostly in the summer months with 8-10" per month.  These three do "ok" in sandy soil here, but seem to appreciate some extra water from my dripline setup.  I think I have a 0.5gph dripper on each one running for 30 minutes.  They are all in full sun here, I'm guessing you'd need to do the same there.

250" is a lot of rain, especially if it's daily.  Our rain pattern tends to be warm and sunny except for 2-3pm.  We get a torrential downpour for 20 minutes and then it clears up again.  I suspect they may be able to tolerate lots of rain if they are in very well draining soil and get a lot of sun.  Habitat pictures of Whitelockii seem to show them on rocky hillsides near a river, so

I don't know anything about Transvenosus or Woodii habitat, so I can't make any semi-rational comments there.

It really is a lot of rain where I live. In 2018 it was close to 300" of rain but 2019 was closer to 200".

Thank you for your input. There are some very happy E. whitelockii at the Pana'ewa Zoo which gets about 125" a year, with various xeric Dioön and blue Encephalartos such as horridus and lehmannii also looking happy.

[Really full garden 1,477]

My highland garden can get almost 300 inches per year.Sometimes 5-8 inches in one night! I have several Encephalartos and have had zero problems with them. Mine are planted on hillsides with very quickly draining volcanic sand and rock. My soil is always moist but never wet. I actually have more problems with South American uber tropical Zamias.

[Morabeza 36]

On 1/19/2020 at 7:00 AM, Really full garden said:

My highland garden can get almost 300 inches per year.Sometimes 5-8 inches in one night! I have several Encephalartos and have had zero problems with them. Mine are planted on hillsides with very quickly draining volcanic sand and rock. My soil is always moist but never wet. I actually have more problems with South American uber tropical Zamias.

Ah! Your highland garden climate sounds very familiar. Thank you for the reassuring information. When you have some time, I'd be interested to learn which species of Encephalartos in your highland garden have performed best