Date: Wed, 02 Dec 1998 15:39:07 From: Bill Tribe <wrt20@cam.ac.uk> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg3789$foo@default> Subject: pygmies and laterite
>Date: Wed, 2 Dec 1998 13:21:11 +0800
>From: "Stuart, Mark" <mstuart@agric.wa.gov.au>
>To: cp@opus.hpl.hp.com
>Subject: Re: Laterite in tuberous drosera cultivation?
>Message-ID: <9178ADEDFE48D111842200805F48482C38B2BD@AIDSVR1>
..
>Given that I am growing these plants in the same environment as the wild
>plants, they have in many instances only moved 50m or so from were they
>were originally growing, the soil type and moisture levels in the pots
>may be the reason for any differences in growth. Recently I have grown
>some of the tuberous hills species in the local laterite sandy, gravel
>loam and the improvement has been significant. I also have used bigger
>pot sizes, 350mm or more in diameter, as I also believe that small pots
>tend to have fluctuating moisture levels which may also be a factor.
>Pot size and the laterite sandy, gravel loam also seem to be a factor
>with the pygmies that grow on similar soils. D hyperostigma grows
>naturally on my block with rosettes often reaching 2 inches or more
>across prior to flowering. If I attempt to grow this species in a peat
>sand mix, often within gemmae shot of the "wild" plants, poor specimens,
>rarely more than a quarter of the wild size, are produced that linger
>and eventually die after a couple of years. Some may last longer but
>have never done well. This has been the experience with D lasiantha, D
>silvicola, D steliflora, D scorpioides and D barbigera. Yet in a 350mm
>or more diameter pot filled with the local lateritic sandy gravel loam
>the plants grow as well as they do in the wild. So well in fact that
>gemmae produced D silvicola, D steliflora and D scorpioides plants that
>are 5 months old are almost impossible to tell apart with rosettes 4 to
>5 cm across.
>In these pots I have observed roots up to 20 cm long emerging from the
>drain holes, supporting the belief that pygmies have a deep root system
>(in comparison to their size).
Hi Mark,
Your mail about the pygmies was really interesting, especially given the
local populations to act as a control. There are a couple of things that
maybe you could expand on. Firstly, given that all pots in all countries
are different, how deep is an Australian 350mm pot? Less than 20cm from
your comment about the roots, but it would be interesting to know.
Secondly, you say you've used the local soil with the bigger pots - have
you had a chance to do these two things separately, and then compare? I
guess the final point is how you water them, i.e. do you try to mimic
what's going on outside, or just stick to a water tray. If the latter then
the watering bit is not too important, perhaps because of your theory that
the bigger pots compensate for fluctuating moisture levels?
I'd be interested to know because though I have only scorpioides from
your list, I've heard of growers in the UK who have had a lot of difficulty
with some of the other species you mention.
BTW, as I'm completely ignorant of soil types, does anyone know exactly
what laterite is, and its essential constituents? Is there a commercial
source for this type of stuff in the UK?
Bill Tribe
Cambridge UK.
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