The Palm Collection at The Coastal Georgia Botanical Gardens

[DavidMac]

The Coastal Georgia Botanical Gardens has been been growing over 35 species of palms in zone 8b

http://www.bamboo.caes.uga.edu/palmcollection1.html .

Their trials are of particular interest to me as I am an assistant director of Grounds and Landscaping at Florida State University in Tallahassee,FL also in USDA zone 8b and wish to expand the number of palm species planted on campus.If you live in the southeastern portion of the U.S. (or a similar climate) I am interested in your experiences with the species in the list-some I know are iron-clad hardy for us but there are a number of other species in their trial list that we have not tried such as Chamaedorea plumosa and Arenga micrantha. Let me know what you would add or subtract from their list based on how they have performed for you.

Edited March 25, 2013 by DavidMac

[GREENHAND]

I have the following palms growing 80 miles south of the Dallas area. zone 8. on Cerar creek Lake Texas.all took 10 deg.

Brahea Armata- Alittle slow but very cold hardy.

Buta Capitata -no freeze damage even below 10 deg

Med palm-very hardy no problems

Phoenix canariensis - lost all fronds but came back now doing well.

Phoenix Sylvestris- did not make it.

Sabal tex- Made of iron does very well

Sabal palmetto- no problems

Trachy fortunei- also does very well

W Filifera- Iron Clad-

I dont know enough to add or delete in in your list that is just some observations. i also lost a true date palm along with the Sylvestris.

[mnorell]

David--

I believe the Bamboo Garden outside of Savannah is a low 9a climate. I have a house in downtown Natchez, Mississippi, which is a medium zone 9a and extremely similar to the climate of Savannah proper, both in terms of averages and extremes. I'm not too familiar with Tallahassee's climate except that its airport average daily temps are a bit warmer though extremes can be lower. I've seen many reports from plant-growers in Tallahassee comment on the great variability in annual minima depending on location and elevation around Tallahassee. I know for a fact there are solid, even warm, 9a areas around Tallahassee. Since the weather service shifted all weather stations into rural areas (generally airports) decades ago, official temperatures favor rural areas, often in cold, low, open areas, so you really have to measure your own temperatures and go from there. It isn't helped by the fact that--though it was promised--the 2012 USDA map did not take into account urban heat islands and elevation/cold-sinks (e.g., the notorious Suwannee River Valley). What I can tell you from my experiences in Natchez, where "average" winters bottom out at 23F or so at my place there...is that many of the palms listed in the Savannah site (which by the way has not been updated since 2003!) just get by in the medium-term in Natchez, where canopy and various other siting tricks give them the extra boost needed in the face of the cold typical of the Gulf states. On a cold radiational morning (and you have a perfect opportunity over the next couple of mornings to observe), go to the wundermap at www.wunderground.com/wundermap and browse around the Tallahassee area, also take a look at other areas in the region to see how the temperature contours really work among the volunteer weather stations that populate the landscape. You can no doubt see what your campus temps are compared to the Tallahassee airport, for a good idea of how downtown compares to the airport where the official temp is measured.

What I can say is that if you are a solid 9a you can grow most of the things on the Bamboo list for 10-20 years between really bad freezes (and I would scratch Cham. plumosa, which from personal experience I know is a goner below 25F, and Arenga micrantha, of which I lost several specimens that could not deal with a hot, humid climate. They want to live in San Francisco, since they come from Tibet!) Most of my Livistonas (chinensis, saribus, nitida) were hurt to varying degrees in the 2009/10 freeze (low 18F and three days continuous below freezing temps) though most have now come back and finally look good again. In the open they are 9b palms, under canopy they are 9a, unless you want leaves to burn off every winter. I think L. decora is perhaps a little stronger out in the open and they grow faster than any other Livistona I've grown. L. mariae also grows well for me there.

Cham. radicalis and microspadix are beautiful and strong, but will look bad if they are subjected to below-20F temps every year, particularly without any canopy overhead. Chamaedorea cataractarum defoliates below about 25F but as long as the plant is mulched decently, it returns easily in spring/summer. Arenga engleri mostly defoliates at 23F at my place in Natchez, even in protected areas. It loses its leaves around 25F in the open with frost. A. ryukyuensis is near impossible to find but Eric Schmidt at Leu says it is hardy to about 20F. You can of course grow beautiful Sabals (palmetto, mexicana, causiarum, maritima, minor et al.) without worry but avoid S. domingensis unless it is somehow under very high canopy, since the leaves cannot tolerate much frost even though the plant's bud is strong to cold. You can grow Acoelorrhaphe wrightii (leaves damage in the upper teens but it is resilient), and Rhapis humilis is quite hardy and dependable (R. excelsa thrives most winters under canopy but will take years to regrow from the rhizomes after a hard freeze into the upper teens). R. laosensis gets knocked to the ground in exposed areas most years but is root-hardy and really rebounds fast, makes a nice, low seasonal accent. Chuniophoenix hainanensis and C. nana are similar to R. excelsa in cold-hardiness but really worth planting in a very sheltered area (they are slow to recover after damage). Caryota monostachya is rather hardy under canopy and even C. mitis has done surprisingly well in a wind-sheltered area under a live oak.

Don't ignore that there are some really nice Trachycarpus now available, like T. princeps, that are hardy and very attractive. Butias of course but also xButyagrus will do beautifully in the vast majority of winters. I've heard the 'Dade City' Acrocomia totai/aculeata is good to about 19F. Phoenix sylvestris 'robusta' has performed really well for me including 2009/10 with just foliar damage and P. acaulis has also done very nicely, also P. loureiroi (humilis form) under evergreen canopy. Copernicia alba has shown itself to be pretty hardy for me as well in Natchez. Keep in mind that ALL of the above except for perhaps the hardier Sabals, Rhapidophyllum, Trachycarpus and some resilient clumpers, will be blasted to smithereens the next time you have a 1989-style winter. Tallahassee has registered around 0F in the past (1899) so it is best to plant your foundation with the natives and strong clumpers that can recover from below the soil-line. Everything else is pretty much temporary so resist the temptation to make too big a statement out of non-hardy palms. Consider planting something like a large-scale grove of Sabal palmetto with an equally dense forest of Rhapidophyllum carpeting beneath in the shade and you will have a thing of beauty that is bulletproof and is "in sync" with the North Florida landscape. Also remember that you can use a lot of beautiful cycads (like the various Ceratozamias, and Zamia floridana) that will harmonize, are surprisingly leaf-hardy, and come back from some pretty hefty cold in bad years.

Sorry for my blathering on with the above list but these are the main standouts I can think of right now after 8 years of trials in a 9a Gulf climate. Search out other local Palmtalk/IPS or Southeast Palm Society folks for what I'm sure will be a much more accurate picture of exactly what you're up against in town. For better updates on the Bamboo Farm you should go to the Hardy Palm & Subtropical Forum (elsewhere on the internet) and search the archives for the Bamboo Farm, as there are several reports with photos available there. All the best of luck in your plantings!

[Kailua_Krish]

Michael,

That's interesting about your experience with A. engleri. I have several of these that never looked worse for wear after getting to about 19 in the 09/10 winter. Granted they are under deep canopy but I assume they are engleri since I got them from South Florida.

-Krishna

[mnorell]

Krishna--

Aside from the issue of deep canopy (and that's a big issue), you may have happened upon either a hardier strain, have larger or more established plants, or perhaps there's an outside chance you have A. ryukyuensis. I went back over my notes and I think I overstated their defoliation in the most protected areas, as I see I didn't get defoliation on those plants until the 2009/10 winter where temps went into the upper teens. But they definitely fried in the open at 23-25F and under open/broken canopy there was at least some damage in the low 20s. I don't think my experiences are that unusual for Gulf-state residents in the 30-32N latitude range but hopefully others will comment here. I think of A. engleri as being very similar to Livistona chinensis in behavior. Their saving grace is that they can recover from their subterranean parts in a 20-year freeze, though they put out leaves rather slowly.

Also, are you sure of the temperature in the immediate vicinity of your plants? If you don't have your own weather station on your property, and adjust for canopy and elevation/air-drainage patterns, etc., your plants may have actually been significantly warmer than you thought. Deep canopy will buy you as much as 7-10F with no wind and short duration since your 50+ degree soil is acting like a giant radiant heater with the canopy holding that warmth in place (I usually have experienced more like a 5F bump in Natchez's 12-hour+ freezes). Winter freezes in the upper Gulf Coast states in general are longer in duration than they are down in Ocala, and duration below the cellular damage-point is what counts. I think that point varies between about 22-25F for most A. engleri and every minute the air-temperature sits at or below this threshold will inflict further cellular damage to the above-ground tissues of the plant. Add to that freeze-drying arctic wind and/or frost formation on the leaves in an exposed location and you have a defoliated plant pretty quickly. Ed Brown (who sometimes comments here) has written that A. engleri suffered 25% damage in the 2003 freeze in Jacksonville at 21F, but he didn't specify canopy amount or duration of the freeze. For those north of where you are, and outside of New Orleans or Jacksonville's warm microclimates, I suspect that it's just safe to say that between individual plant genes and variables in siting/location, it's best to put several around in various exposures and see if you're lucky enough to get a happy plant that doesn't damage most years. I think A. ryukyuensis would settle the matter and give a reliable plant for those colder areas, were it available...

[Kailua_Krish]

Of course I dont know what the immediate temperature they were exposed to is but considering my queens and philodendrons were defoliated, my mules damaged, and several L. decora killed I felt it was safe to assume it got below 20 in my yard. I was addressing the fact that you said even in a protected location A. engleri defoliates at 23, which I have not found to be the case for me (my palms are from multiple sources so I doubt its a particular type). This palm seems to be extremely happy in deep shade as long as it gets adequate water and probably should be planted in such a location in 9a with other plants protecting it from wind. The duration of freezes could potentially be important since it usually warms up quite rapidly in the middle of the state but in 09/10 and 10/11 freeze durations were horrible, even in Florida.

As far as A. ryukyuensis goes, they should be coming on the market fairly soon. 2 or so years ago RPS offered seeds for it and mine are starting to reach the 1-3 gallon size and my plant cultural practices are far from ideal so I'm assuming others will have larger plants to sell. Ive started planting mine out in slightly more exposed locations. Next time we have a big freeze we'll see how cold tolerant they end up being.

[Alicehunter2000]

Will be following this thread. I think size matters when considering cold hardiness. I would suggest that indicating size would be helpful when analyzing and reporting on cold hardiness.

[Alicehunter2000]

Will be following this thread. I think size matters when considering cold hardiness. I would suggest that indicating size would be helpful when analyzing and reporting on cold hardiness.

[Kailua_Krish]

Mine were about 3 gallon sized plantings, granted they were large for their pots.

[DavidMac]

Thanks for all the comments and observations-there are so many variables to consider that affect the survival of plants. I appreciate knowing what your experiences are realizing that under my conditions with the palms that I acquire that my results may be different. I remember a large clump of Arenga planted on the campus of the University of Florida in Gainesville-zone 8b (where I attended college) but I am unsure which specie it was-but it was growing in a protected courtyard in shade. We consider various campus microclimates when trialing palms and I certainly would like to plant an Arenga

[_Keith]

One things I can say for sure is there is freeze wet, there is freeze dry, there is frost, there is freeze plus frost. All four are different, and all four can have dramatically different affects. In addition there is an affect from post and pre conditions. A palm that might recover from a single night at 25, can be killed dead by a night at 28, followed a week later by a night at 29.

Arenga engleri, survived 3 consecutive nights at 20,19,21 and many minor freezes same winter, literally unscathed, but it is in a frost free environment with very high cover, and it was a dry winter.

Washingtonia filibusta same freeze plus frost 4 of 5 unscathed, 1 had spear pull, but grew right out of it in first 3 months of summer.

Jubaea x Butia, same freeze spear pull, grew out of it but took over a year to recover. I am convinced had we had even a mid 20s freeze the following year it would be long dead.

Livistona saribus, same freeze, minor leaf burn on one not exposed to frost, one that fully exposed to frost 90% defoliated, and looks to be permanently stunted and is one quarter the size of the former.

[Kailua_Krish]

Keith,

My experience with the cocoid hybrids has been similar that at young ages they will get spear pull at quite high temps. I wonder why?

[sonoranfans]

Keith,

My experience with the cocoid hybrids has been similar that at young ages they will get spear pull at quite high temps. I wonder why?

have been wondering about the jubaea x butia F1(jube mother) in florida. I am thinking it will be less robust, more sensitive to the hot weather, from the dominant maternal genes. Many palms of young age tend to get spear pull more so than the larger versions, lower to the ground means more moisture and frost. Smaller palms are also not likely to have established root systems, all bets off on cold hardiness in that case. I have seen a number of very small cocoid hybrid palms planted out in the elements, it seems you take a risk planting small palms out.

[Kailua_Krish]

Mine survived but barely This past warm winter really helped the JxS and BxP get o n their feet

[_Keith]

One surprise I got was that I thought with the one Jub parent it would want to be on the dry side. I was very wrong. Last year from summer to winter we had record rains, 40+ inches literally never drying out and it absolutely loved it.

[Turtile]

I think Arenga micrantha was found not to be the most hardy of the genus.

I went there last year and don't remember seeing it.

[mnorell]

Of course I dont know what the immediate temperature they were exposed to is but considering my queens and philodendrons were defoliated, my mules damaged, and several L. decora killed I felt it was safe to assume it got below 20 in my yard. I was addressing the fact that you said even in a protected location A. engleri defoliates at 23, which I have not found to be the case for me (my palms are from multiple sources so I doubt its a particular type). This palm seems to be extremely happy in deep shade as long as it gets adequate water and probably should be planted in such a location in 9a with other plants protecting it from wind. The duration of freezes could potentially be important since it usually warms up quite rapidly in the middle of the state but in 09/10 and 10/11 freeze durations were horrible, even in Florida.

As far as A. ryukyuensis goes, they should be coming on the market fairly soon. 2 or so years ago RPS offered seeds for it and mine are starting to reach the 1-3 gallon size and my plant cultural practices are far from ideal so I'm assuming others will have larger plants to sell. Ive started planting mine out in slightly more exposed locations. Next time we have a big freeze we'll see how cold tolerant they end up being.

Krishna--

If you had damaged mules I agree you must have been down in the teens. I've not seen any damage on mine in Natchez (though I'm pretty sure mules are a variable due to specific parent hardiness and combination genetics). And I can't believe you lost Livistona decora...I had seedlings in a densely planted 3gal community pot that made it through just sitting under a big patio umbrella through that horrendous pair of winters. And there were a pair of larger specimens in St. Francisville, Louisiana (just north of Baton Rouge) that were damaged but fully recuperated (though they were inexplicably removed last year). I wonder if in the Gainesville-Ocala zone a downside might be that you can still have some warmth and perhaps some of these palms begin to become less hardened to cold. I still can't believe how cold it can get in that transitional zone north of Orlando. Further north I wonder if it might be possible to see a little more hardening-off to cold because when winter settles in, it really settles in! Butia in particular are reported to do fine way up into North Carolina and that is a long, cold winter. Although on the other hand I've heard people from Ocala talk about Phoenix roebelenii defoliating every winter but popping right back. I tried them several times in Natchez and they fried up pretty quickly in not-so-bad freezes and never did I have one come back after even a typical 9a Natchez winter. So at least that species seems not to appreciate sustained and repeated hard knocks. As Keith says, there are so many variables to cold in winter, it's very hard to make hard-and-fast rules.

And my A. engleri were definitely on the smaller side when planted. As I remember they were roughly 2-gallon size. I'm glad to hear there are some A. ryukyuensis coming into circulation as well. Certainly those 8b/9a areas need some more dependable palms!

[Kailua_Krish]

It's definitely an odd zone, Ocala even more than Gainesville. The climate is more pennensular except for those 1/20 winters when it acts continental. Unfortunately this makes the plant species from the lower south languish except during those years with cooler winters and tropicals get outright destroyed when we get the really cold weather (particularly when it's wet cold as often happens). I think my L decora were just too small (1 gallon) and were exposed to too much frost. The really stupid thing is that after it happened the first year I told myself it wouldn't appen again so I replaced them, and another 2 of them died. So between the first and the second freezes I am left with 2 L decora where I started with them but after they grew their buds back they've been much hardier. As far as Robelleni goes I used to have several large ones but they all died in 09/10. A few smaller ones regrew from below ground and all of the hybrids made it (I seem to get a ton of hybrid Phoenix when I buy these from big box stores, I've ended p with several medium sized Phoenix hybrids that defoliate around 22-23)

Ps Im glad we have a cold hardy forum to discuss all this, climate intricacies on species are key in borderline zones!

[DavidMac]

I agree with with Krishna- Marion County is indeed rather odd. Good air drainage from being on high ground and proximity to large lakes can give considerable protection such as at Citra in the extreme north part of the county south of Orange and Lochlossa Lakes. Areas away from the urban heat of portions of Ocala that are lower and/or away from major lakes can be very, very cold- such as Silver Springs Shores south of Ocala. Such spots indeed can be colder than Gainesville 50 miles to the north!

[Kailua_Krish]

Soil also has a lot to do with the temperature retaining effects, the sandier it is the colder it gets!

[sonoranfans]

One surprise I got was that I thought with the one Jub parent it would want to be on the dry side. I was very wrong. Last year from summer to winter we had record rains, 40+ inches literally never drying out and it absolutely loved it.

Very interesting Keith,I always though neither parent liked that kind of wet. Do you have a pic of the palm, and a close up of leaflets? I was wondering if the tips are hooked, or if the leaflets are double tipped(jubaea influence). Also are the petioles straight or recurved, and do the leaflets have the tell tale v crossection(jubaea). Is this a patrick shafer hybrid? Sorry about all the questions, I was at jungle music recently and saw a number of 15 gal size hybrids(j x b, b x j) and observed these traits. Edited March 28, 2013 by sonoranfans

[_Keith]

One surprise I got was that I thought with the one Jub parent it would want to be on the dry side. I was very wrong. Last year from summer to winter we had record rains, 40+ inches literally never drying out and it absolutely loved it.

Very interesting Keith,I always though neither parent liked that kind of wet. Do you have a pic of the palm, and a close up of leaflets? I was wondering if the tips are hooked, or if the leaflets are double tipped(jubaea influence). Also are the petioles straight or recurved, and do the leaflets have the tell tale v crossection(jubaea). Is this a patrick shafer hybrid? Sorry about all the questions, I was at jungle music recently and saw a number of 15 gal size hybrids(j x b, b x j) and observed these traits.

I'll take a pic tomorrow. Due to its location and size, it is not a very photogenic palm, but I will see what I can do.

[floridagrower]

We've got numerous mature specimens from that list around, if you know where to look. You wouldn't know it because this town prides itself on being anti-Florida. In town is even milder than that garden. Do not let the airport's numbers fool you. Let me know what you are looking for in a PM and I can point you to a local version. Oh and Chamaedorea plumosa is no good. I agree with the above...