Date: Wed, 28 May 1997 11:00:53 -0700 From: Wim Leys <wim.leys@lin.vlaanderen.be> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg2089$foo@default> Subject: Re: cp roots
Hi Mark,
> Most cp's are wetland plants and can live in water-saturated soils,
> but it is my understanding many will die if they are kept in
> waterlogged soils for an extended period. My question to everyone is:
> do some cp possess a means for delivering oxygen to their roots, like
> aquatic plants do (aerenchyma tissue?), or do they simply have a high
> tolerance for anoxic soils? If they do not have aerenchyma, then this
> implies they cannot survive in saturated soils in perpetuity and must
> spend at least part of they year with their roots above the water
> table. This would explain why they are usually found in semi-pocosin
> habitats.
This answer somehow completes my response to "Ants in my plants" Digest
1094. In Schnell's book "CP's of North America and Canada", the author
writes that Sarracenia's tend to become bigger when they grow in soil
with a higher water level. As I was allways trying to grow the biggest
plants, I have grown them in tables with a water level at soil level
during a few years (during the whole summer, the tables are dry during
winter).
When repotting them, I noticed a typical smell from the soil, due to the
lack of oxigen in the soil. The roots were sometimes black and brittle
(dead).
Somebody else told me that it is far more important to keep a constant
water level than a very high one. The plants will adopt their roots to
the level where they can find the right amount of water and oxigen. If
the water level is very high they will form shallow roots, with a deeper
water level, the roots will also grow deeper. If the water level
constantly changes, the deeper roots will die when the water level stays
high for a while and the plant will grow deeper roots when it gets
drier. This "disturbance" of the root system constanly stresses the
plant. S. Leucophylla reportedly is sensitive to this kind of stress.
Since my plants grow in a water level of a few cm (1 inch), the soil
doesn't smell anymore.
A friend of mine (hi Peter) has recently installed / is still busy
installing and improving another system : a water pump floods his tables
a few times a day, the water is allowed to drain back to the rain water
barrels from where it was pumped up. This way he not only keeps the soil
in the pots constantly wet, but it also allows more oxigen to enter the
soil. I'm convinced his plants will benefit from this setup. (I will
stop describing his setup here, as he is far better placed to do so.)
BTW What is "semi-pocosin" ? I don't have an English dictionary here at
hand.
Hope this helps
Kind regards
Wim
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