Re: Astelia longevity

david feix wrote:
> 
> Jaen,
> I haven't your experience with growing this long
> enough to know if they do have an upper age limit to
> them.  I would tend to suspect either something eating
> the roots or possibly a disease, and lastly perhaps
> losing vigor from having bloomed.  They seem to grow
> for years without blooming.  I wouldn't have thought
> that they would die after blooming myself, as they do
> so vigorously form immense colonies of individual
> crowns, although again, I haven't seen any old enough
> to show die back at the center of plants.  I would
> have predicted longevity similar to Phormiums, which
> seldom show dieback here in California, although all
> too many revert to less colorful foliage as well as
> getting too large!
> 
> The one problem with A. chathamica is certainly that
> it gets so much larger than its cute appearance in a 5
> gallon nursery can, and A. nivicola 'Red Gem' is a
> smaller growing substitute to 2.5/3' in height, more
> manageable for smaller gardens, although somewhere
> inbetween being a deep purplish red and the bright
> silver of 'Silver Spear'.  I don't know of any growers
> selling deeper purple cultivars, and would suspect
> that A. nivicola itself has quite abit of color
> variability from seed propagated material.  There is a
> whole range of Astelia species out there, some even
> growing epiphytically on tree branches in New Zealand,
> but I suspect that many like wetter conditions than
> the average California garden.  No doubt they would
> thrive for you with your 60 inches of rain and
> cool/moist coastal summers.

Hi David
You are certainly right that A nervosa is a variable species colourwise
which the NZ Encyclopedia of Native Plants says can vary from reddish
tones right through to green or silver. It also says the depth of the
colour on red forms is partly associated with the amount of sunlight the
plant receives. This  particular species is apparently intolerent of wet
feet and may rot in very humid areas unless the soil is very well
drained. In fact most of the NZ species grow out on grasslands and
herbfields and demand perfect drainage, though a few are adapted to less
well-drained areas.

The best red form available in the local trade appears to be "Alpine
Ruby". This is particularly recommended for containers with the proviso
that "Good drainage is absolutely essential".There is also a reminder
about the effect of sunshine on the depth of colour.

No such problem is mentioned with A chatamica though about which it
merely says "prefers a rich soil, but will tolerate some dryness". The
soils which it occurs in naturally tend to be moist and peaty so it does
not seem likely dampness is ever a problem..

As to the possibility that flowering is weakening, there is no
indication at all either in the Encyclopedia or the NZ Flora that any
species has monocarpic tendencies. Certainly the common one in our local
bush (lowland forest) - A. fragrans - is covered with bright orange
berries most summers and always looks fine.

A solanderi is the perching one. We see a lot of it in our forests along
with several other different perching plants. Epiphytes are of course
typical of rain forest and our NZ bush is actually one of those rare
things a _Temperate_ rainforest, so lians and epiphytes occur freely. I
have been studying the occurrence of epiphytes in our local bush area
and have come to the conclusion they rarely get a hold on trees until
their vigour is declining. Perhaps healthy young bark in some way
discourages them from getting a hold.

Once a tree becomes laden with epophytes they seem to flourish in
proportion to the waning of its own growth until the host eventually
dies. They continue to live on the dead tree until they grow so heavy
that some strong gust brings the whole thing crashing down. This is an
important part of the forest cycle as the  felling leaves a  hole in the
canopy letting in light and  the rotting of the old trunk provides the
food for the new young tree or trees which will take it place. On old
trees which are just about due for nature's felling the size of some of
the clumps of Astelia and other epiphytes can be truely amazing (several
feet across), especially when you think they take nothing from the tree
itself but depend on windblown debris for much of their sustenance.
> 
> I can't quite imagine gardening with 80 mile an hour > winds each winter, must be a lot of cleanup the next  day!

I can quite easily, living near the funnel of Cook Strait(!), though our
big winds mostly occur from spring into early summer when they can do
awful damage to young foliage in exposed situations. Ours is not however
the only part of the country to have such gales. I can easily undestand
why there are so few native _deciduous_ trees here and so many
evergreens with leathery leaves!

As to the cleanup, with such winds occurring fairly regularly the trees
are kept well pruned, so not much comes down each time!  if one wants to
grow softer things shelter is the only answer and I guess most keen
gardeners here become experts on this.

Moira
-- 
Tony & Moira Ryan,
Wainuiomata, North Island, NZ.     Pictures of our garden at:-
http://mywebpages.comcast.net/cherie1/Garden/TonyandMoira/index.htm
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