Oh No! A Boophone disaster!

Jacob Knecht jacobknecht@gmail.com
Sat, 03 Oct 2009 23:05:56 PDT
Aloha Ken,

Thankfully coastal California (including San Diego) at least have cooler
night-time temperatures than in most other parts of the US during the
summer.  Here in my climate the diurnal temperature differential averages
around 15°F (9.5°C), certainly less than it swings in southern California,
especially in winter months.

I think that once your seedlings have completely filled their new containers
with a robust root system, you can certainly add more organic matter - all
depending on how much water they will be getting and/or how fast they will
be able to dry out between waterings.  I understand that you grow many of
your bulbs in the ground and one of the many advantages with this is that
the capillary action of the surrounding soil will help moderate moisture
levels (especially if the native soil is a well-drained loam).

To me it seems that many of the African Amaryllidaceae native to areas with
pronounced dry seasons (nearly all of them are) possibly depend on their
extensive long-lived perennial root systems just as much *if not much
more*than their actual bulbs for nutrient and water storage.  When I
rootless bulbs as imports, I jokingly (and quite incorrectly) refer to them
as 'meristems'.  My point in bringing this up is that if roots are lost to
conditions conducive to root rot and/or related opportunistic pathogenic
infections is that the medium used to get bulbs to regrow roots in 'triage
conditions' may not be the same as that you might grow them in long-term.

I agree with Tim's comment.  All of the winter rainfall bulbs that Nhu and I
grow in California, especially the ones that come from very dry regions such
as Namaqualand and the Atacama, are potted in media that feature 10% or less
organic components (oak leaf mould is great).  Losing a decade's worth of
roots on a rare, valuable or simply beautiful* Boophone* or *Brunsvigia* is
simply too much to risk using potting mix that may break down faster than
these species tolerate re-potting without setbacks.

Other growers on our list may have more to add with respect to perlite vs.
pumice, but generally the advantage of pumice over perlite is that pumice is
heavier and more sound structurally.  Thus it tends not to float or compact
as easily, and I understand that perlite is more moisture retentive than
pumice.  O/T: Maurice Levin of A&A Cycads in North Hollywood, California
often employs a mix of 1:1 pumice and perlite for re-establishing offsetts,
newly-dug or imported cycad caudexes, and I have done the same with good
results.  Years later once they are established, more organic material can
be added when there is less danger of too much moisture present when a newly
disturbed plant (or bulb) is more vulnerable to rot.  I think this example
can be applicable to bulbs that are particular about moisture and root

I'm sure your young bulbs will return to rude health with some time and
care. :)

Jacob Uluwehi Knecht
Honolulu, Hawai'i

2009/10/3 Ken <kjblack@pacbell.net>

> Thank you, Jacob!
> I will take your advice and repot in a mostly pumice medium, most likely
> with no organic material.  These had been in a homemade soil mix of about
> 40% DG, 40% perlite, 10% local (clayish) soil and 10% home-made fine
> compost.  I will leave out local soil and compost ... what do you think of
> perlite as an component with pumice?  Coastal San Diego is usually
> relatively cool, but I should have been more aware of the hot humid weather
> that can occur here in late summer.
> Ken
> From: Jacob Knecht <jacobknecht@gmail.com>
> Subject: Re: [pbs] Oh No! A Boophone disaster!
> (... was due to and was accelerated by the high humidity ...
> ...
> and let them dry and callous for a week or two before
> re-potting into pure pumice.  It took a few months of watering very
> sparingly and being patient for the bulb to resume leaf growth only a week
> ago.
> Although losing so many roots may set your *Boophone* back, as long as
> their
> basal plates are intact, I think they will be fine.  However I would repot
> them into a medium that has a high gas exchange to moisture retention
> ratio,
> and water sparingly until they have shown a positive response with new leaf
> growth (usually predicated by new roots).
> _______________________________________________
> pbs mailing list
> pbs@lists.ibiblio.org
> http://pacificbulbsociety.org/list.php
> http://pacificbulbsociety.org/pbswiki/

More information about the pbs mailing list