establishing seriously marginal palms

[Bennz]

Looking at the California coconut thread encourages me to puch the boundaries again. I live in a cool maritime climate where summers are pleasant and winters coolish. I have about 200 acres that do not ever see frost at all.

I like the idea of establishing tropical palms, and as I get reasonable winter sunshine, I often dream about establishing Cocos, Roystonea etc here, by utilising passive solar techniques such as planting on plastic covered mounds with greenhouse film enclosures, which should easily give me at least subtropical equivalent winter temperature conditions. I could not replicate lower latitude sunshine hours of course, but that may or may not be a problem.

While I strongly suspect establishment could be achieved, what next? Eventually they would outgrow their enclosures, and need to be exposed to normal outside air temperatures. If a palm that needs warmer temps gets established here and eventually grows to a size which would make it impossible to do more than keep the soil warm and dry in cold winter conditions, would it survive? I expect it would not look great even if it did survive. Anyone tried this?

I did a soil warming experiment with bananas once. I planted Dwarf Cavendish, Rajapuri, FHIA-3 and FHIA-17 onto  a mound which contained circled 19mm pipes through which heated water was pumped. I set the thermostat to 30C for summer, with the idea of dropping it to 20C in winter, which would keep the soil temps 5-10C warmer than natural temps would be. Of these banana cv.s, FHIA-17 and Dwarf Cav. dont do well here normally, but the other two cv.s fruit and grow adequately.

The heated bananas grew a lot faster than the unheated ones, and in the summer season they thrived. UNfortunately I neglected to turn down the thermostat in winter, and noticed that the bananas were beginning to develop 'choke', and the leaves were clearly not elongating through the throat as fast as they were being produced by the rhizome. At this point I decided top leave the thermostat at 30C and see what happened. They looked ok until we had a real cold spell across the country. Air temps at 30cm above ground dropped to 2C. The unheated plants were totally undamaged, but the heated ones collapsed dramatically.

I concluded from this experiment that it would have been better to heat the soil passively from sunhine, which would give a more accurate reflection of natural seasonal variation. If this was combined with a greenhouse enclosure, growth would be fast. If this is transfered to palms, what would happen when the enclosure was removed? In my climate, if a palm got to about 2-3m tall before the enclosure was removed, lowest air temps the growing point experienced during the following winter would be around 3C, which is usually about the coldest night of the year here. But we do on occaison get days that don't go much above 10C.

I know it would be easier to stick to the easy palms like nikau, kentia, king etc. Must be something wrong with me!

[Walter John]

I know it would be easier to stick to the easy palms like nikau, kentia, king etc. Must be something wrong with me!

Nothing wrong with you that 99% of people on this board also suffer from. Has various descriptions, Palmitis etc.

[DoomsDave]

My advice is listen to what the old hands say, but try new things anyway.

As experienced as some people are, they miss things, too.

As Wal pointed out, we all pretty much want what we can't have, but what's glorious is finding something new that we couldn't make it that will.

Keep in mind that marginal varies all over the place, and that while NZ is similar to So-Cal., it's also very different, too, including (I've been advised) much higher humidity.

Before I decide about something difficult (i.e., will I pay an arm and a leg for one?) I try to find out as much as I can first.  

In particular, remember that just because a palm comes from a tropical zone, does not mean that it must have tropical conditions.  Some palms and other plants (e.g., Gardenia vetchii) are much more adaptable than their present habitats make one inclined to believe.

dave

[Really full garden]

I think every climate has its limitations (even Leilani Estates).I live in a truly tropical climate(Pacific coast of Guatemala) where the temperature never drops below 65 and day time temps are always in the 90s. We have very severe wet/dry seasons.It pours daily for five months and then we have five months of no rain and strong dry winds.It is diffficult to find species that can survive both extremes.I think temperatures are just part of the problem.

                                                                 Scott

[Dave-Vero]

The closest I've come to your area was to pay a young Portland, Oregon artist for an etching before he went to New Zealand on his honeymoon, for what turned out to be a nice etching of Cape Kidnappers.  

I'd think your list of possible palms would be similar to what makes it at some point or another on the California coast.  Certainly not Oregon.  So no Rhapidophyllum.  Maybe some higher-elevation American species?  Or whatever would grow at elevation in Thailand?

[Ashton]

(Bennz @ Jul. 11 2006,17:02)

QUOTE

I concluded from this experiment that it would have been better to heat the soil passively from sunhine, which would give a more accurate reflection of natural seasonal variation.

Bennz

I have a few baseball sized dark, almost black, rocks that collects so much heat in the day, you can hardly pick them up.  I also have an artificial putting green with dark green and black sand imbedded and you can't walk on it in bare feet in the summer.

Perhaps if the top few inches of soil were this black sand topped with some of these larger stones, the soil temps might stay a bit warmer.  I'll purchase a larger quantity and try some soil temp experiments.

[richnorm]

Ben,

I've been thinking about getting a kiwi half-round barn and replacing the corrugated iron with polycarbonate (and suitable reinforcing).   I could then put four or six large piles around it and jack the whole thing up when the first palms get to six metres!  From what I have heard from the old hands here the problems we have are lack of summer heat and too much winter wet.  Cold per se is not often the killer in frost free areas it just slows some palms to zero.  My small unheated greenhouse gets almost as cold as outside but the protection it affords is the difference between life and death for my more hopelessly optimistic purchases.  In the meantime I'm very happy to be able to easily grow the likes of hedyscepe, chambeyronia, dypsis onilahensis, ceroxylon, caryota gigas, jubea etc etc - and Nikaus!

[Bennz]

Dave-Vero,

I can see Cape Kidnappers out the window every day. You choose the right part of NZ anyway. Yes there are a lot of easy palms I can grow here, and yes I should stick with them. Rhopalostylis, Archontophoenix, Howea, Hedyscepe, Parajubaea and Ceroxylon will probaly always be my first choices. Malcolm Thomas a little way up the coast from me has got an amazing collection of palms. Its the challenge of the impossible that is intriguing me, not the absence of easy palms.

Ashton, I think warming the soil will be the easy part, especially if using mounds to keep the cold from getting in by capillary action in winter. The question I have is really whether or not the growth potential difference is sufficient to make it worthwhile. Maybe soil warming might be a useful tool to get my Howea to grow more quickly?

[Dave-Vero]

Bennz, from limited observation of my young Archontophoenix cunninghamiana, it seems not to  grow at all until daytime temperatures reach well into the 80s F (25 C), then it grows like a weed.  This gives it a solid 5 or 6 months.  My interest in Archontophoenix comes largely from our climate being quite similar to parts of coastal Queensland, so much so that the US Department of Agriculture conducts research on biological control of Florida's pest plants from Australia in Townsville.  

In an equable climate like yours, I wouldn't be surprised if a few walls, a small pond, or even that black gravel could make for a distinctly different microclimate.  In England, it's always fun to see what they can grow in such spots--someone recently even grew avocado fruit outdoors in London, according to BBC.  

My etching of Cape Kidnappers is by Mike Southern.  He and his wife definitely want to return.  To judge from his new webpage, selling the New Zealand etchings before he even made them was a big success--none are for sale!  Typical of him, the etching features a black-and-white version of a technicolor sunrise.   http://www.mikesouthern.com/wp/index.php

[Bennz]

Thats interesting, because here in NZ A. cunninghamiana is likely to be classed as a weed in the Auckland district soon becasue of its potential ability to naturalise. Mine grow all year around, more slowly in winter of course. This palm here would grow well even in areas that rarely get up to 25C. I would almost suspect that your palm is mislabeled. Or the other option is that you are just so familiar with subtropical growth rates that you don't notice what it does in winter! I have had palms of this species growing in a very dry infertile area still grow from seedlings to 1-1.5m clear trunk (to bottom of crownshaft) in about 3 years with no fert. or water added.

Here are some of my A. alexandrae var. beatricae, growing about 20 degrees of latitude further away form the equator than their habitat.

[Walter John]

Bennz, from limited observation of my young Archontophoenix cunninghamiana, it seems not to  grow at all until daytime temperatures reach well into the 80s F (25 C), then it grows like a weed.

Can't be A.cunninghamiana. Unless yours has a problem. A.tuckerii would have that growth requirement/condition though.

[Dave-Vero]

Bennz, thanks for that lush photo.  

My putative A. cunninghamiana (obtained at Central Florida Palm Society sale at which the grower certainly tried to provide accurate identification) held a spear all winter, unfurled it as soon as we reached summer temperatures, then unfurled the next just a month later.  The current spear looks like it'll take a bit longer.  The plant is maybe 2.5 m tall, so it has enough leaves to feed quick growth, while the size of each new leaf isn't so large that it requires huge resources to construct.  So the plant can grow fast.

At an international meeting in Fort Lauderdale, I got to see a presentation on exotic pest plants in the Auckland area a couple of years ago.  It seems that exotics problems follow suburban sprawl, so the strategy was to encourage people at the urban edge to landscape with native plants, or at least avoid species known or likely to become pests.  A. alexandrae is becoming a pest on Maui and some other areas of the Hawaiian Islands.  So far, there's no concern here in Florida, partly because Archontophoenix seem to resent dry weather.  I might ask around to see if anyone's spotted problems.  Archontophoenis species are NOT currently considered problems in the Miami area.  

I've planted several Archontophoenix tuckeri (excellent odds of being correctly identified) in the past 6 months and they look to be enthusiastic growers.  The plan is to have a leafy thicket like yours in a few years.  I figure these plants grow so fast that they are almost disposable--just replace any that are damaged by cold or windstorm.

We, by the way, have a very good mango climate (like India, with dry winter, hot wet summer), except for the threat of freezes.

[Dave-Vero]

Wal,

you posted after I'd started scribbling.  Thanks for that valuable tip.  I'm quite sure about the identity of the "A. tuckeri" in my yard (the grower has impeccable science credentials).  So in a few years, I can play plant taxonomist (that's my training) and see what I've got.

[Bennz]

Dave, your comment re. the excellent mango climate has silenced me. Mangos, mangos mangos. My in-laws have a small mango patch (around 100 trees) alongside their banana plantation on their farm a little south of Brisbane, and I don't think there is another fruit to compare to a fully matured ripe mango. There are mango cv.s that have fruited to commercial quality in NZ, but they all got destroyed after the introduction of some allegedly exotic virus about 25 years ago. Unfortuantely this now means Mangifera is on the NZ potential commercial crop list with extreme importation restrictions, and a minimum $30,000 per importation of new genetic material.

For the real lush look you need to look slightly to the right of where my picture was taken. You can just see some banyan foliage in the top right corner, I just love those banyan trees. Nothing is nicer to my mind than a heap of pinnate palms coming up through a banyan tree. Mine are Ficus columnaris, which have been known to reach 5 acres in size with over 1000 trunks. So I'll be able to fit a fair number of palms underneath them! They are a little slow here of course, although this tree in picture below has done ok, collected as seed in habitat in 1999, and now about 4m tall and wide after several major prunings.

Cool climate gardeners trying to reproduce the tropical look with cold tolerant versions of the plants you Florida people see everyday!

[Kris]

hi Bennz,

This is Kris from S.india, i agree with wal & dave that their is

nothing wrong experimenting, since you will be the first to teach others and even prove some guys in your area that they are wrong.

Palms are very peculiar plants only by testing one could say

wheather it suits your climatic conditions.

And as for as Mangoes are concerned, in india the summer fruit is jack-Fruit and mangoes.here the king of mangoes are

bangana palli From Andhra Pradesh & AApose (Alphonesa) from Goa. while other varities are malgova, peeter, heemomshah,Rumani,sindura,kelimuku,neelam,etc...

All the above are fully fleshy,sweet and are in golden orange colour when rip. hey at present in S.India it is mango season

going on. all the hotels make all items from the mango fruit_

Mango juice,mango pickles,gravey and side dishes and deserts

& Salads made of mangoes.mangoes are consumed with lunch and it is a hot item so,after consuming it people take milk or butter-milk and avoide water for a hour or so.

And now to your 200 acres of land try making it a paradise or mini-jungle with all the plants that would grow healthy in that climatic region and the palms of your dreams.

I believe One Human being should plant at least one tree and

feed a least one domestic pet.

Love,

Kris from South India.

[Dave-Vero]

This weekend is the annual Mango Festival at Fairchild Tropical Botanic Garden in Miami.  They've worked hard over the years to persuade local residents that mangoes are perfect fruit for growing at home.  My young trees are "Mallika" a very compact (2 meter) new Indian variety (named, I suspect, after a movie star) and "Lancetilla" a late-season mango named for the botanical garden in Honduras.  

We have problems with non-native  Ficus.  Trees of some species are too likely to tip over in hurricanes, to be safe.  Also, the pollinators for several species have arrived here, so seedlings appear in unwanted places.  The native Ficus aurea can be a bit of a nuisance, since it's a strangler.

[Guest]

Archontophoenix cunninghamiana in my neck of the woods, considered by many to be

marginal for this species, yet these are 3 winters in the ground and very happy

with their hot, Western exposure: (and BTW, this house is for sale for 1,400,000)

[bubba]

Dave, You are in Vero but list your zone as 9a. I have observed mature Cocos nucifera in many locations in Vero together with many other rather tropical specimens.Are these specimens simply located in micro-climates?

[Dave-Vero]

Bubba, I corrected my blooper.  Not to mention added yet another hardiness assessment, from the National Arbor Day Foundation.  Wikipedia has an interesting and (from what I know of it, accurate) entry on this vexed subject:  http://en.wikipedia.org/wiki/USDA_plant_hardiness_zone

I'm a short distance south of the Vero Beach airport, so its temperature records are highly relevant, except trees provide some wind protection and a bit of frost protection.  The largest coconut I knew in town was on the oceanfront, on the south-facing side of a condominium north of Kiwanis Park.  It was looking bad the last time I peeked at it.  The Vero Colony Office Park (British Caribbean-style, land side of Ocean Drive at Banyan, just north of Bobby's) has several nice ones, and of course there's youngsters all over town.  I doubt that any are older than 1989.  Same goes for the Melbourne (Fla.) beaches.