Re: Tuberous Drosera... Help!?

From: Phil (cp@pwilson.demon.co.uk)
Date: Sun Mar 16 1997 - 12:16:35 PST


Date: Sun, 16 Mar 1997 20:16:35 GMT
From: Phil <cp@pwilson.demon.co.uk>
To: cp@opus.hpl.hp.com
Message-Id: <aabcdefg957$foo@default>
Subject: Re: Tuberous Drosera... Help!?

Rick,
>
> My very first tuberous D. arrived from Alan Lowrie a few weeks ago(!). I've
> left the tubors in the bags they came in and every few days I check to see
> how they are doing. Well, now they are "doing" and I could use some advice.
> I have a fair collection of other CP in a greenhouse, but I know tuberous D.
> require special handling...
>
> The ones that are showing activity are the D. macrantha and the package of
> "Lucky Dip" (10 unlabled tubers). Each one is evidencing a single long (2
> cm.) shoot that is quite thin. I would guess that this is a stem. It LOOKS
> like a stem, but it might well be a root. Root or stem is the first
> question. I don't want to plant them upside down :-)

This is the stem. Plant the tuber a small way into the soil - about 2.5 - 3
times the depth of the tuber is about right. Incidentally it wouldn't matter
much if you did plant the tuber upside down as the plant will automatically head
for the light.
 
> Next: I wasn't expecting to see any activity until late Summer or early
> Fall (which I know it is in Australia). I presume my tubers are jet lagged
> and confused. I am guessing that I should plant them now and try to extend

Correct. Tuberous Drosera are winter growers and actually begin growth around
early fall. In norther hemisphere conditions this means the tubers will be out
of sync and try to grow in our spring.

> their growing season through my summer and into their next normal dormancy
> (I am in California)?

It all depends. Generally I find the in their first year in norther hemisphere
conditions the plants will emerge for a shorter period, tending to go dormant in
a few months time. This may be because of the longer day length or it may be due
to higher temperatures. Typically a tuber will spend about 6 months in dormancy
so will tend to re-emerge around Christmas time. After another year the tuber
should be fully adjusted. However, not all tubers keep to this plan. Some go
dormant very quickly while others can stay up all summer. You have to let the
tuber sort itself out, which it will do in the end.

> Potting media: I am going to use 2/3 sand and 1/3 milled peat in a 6" pot.
> I'll plant the tubors a few inches down. Unlike my other CP, I won't stand
> the pots in an inch or so of wather, but I will keep them constantly moist.

I like to add some coarse grit to the mixture, say another third as this opens
the soil up considerably. Also it helps to use extra deep pots. I've found some
here in the UK which are about 1.5 times standard depth. One of the advantages
is that I can be less fussy with watering and can leave the pots standing in
water - an advantage if you cannot get to the plants each day.
 
> I also have a single D. gigantea tuber that is not yet showing activity
> along with a couple of D. marchantii. When they begin to come out of
> dormancy, I will treat them in same way. I sure wish the book search folks
> would find one of the growing guides I'm looking for. It's nerve wracking
> taking on a new species :-)

D. gigantea tends to be very late to emerge. Mine do not usually appear until
around Christmas. It is probably safer to plant all these tubers regardless of
whether they are coming into growth. Give sparing amounts of water until growth
is actually seen.

> Any other hints on growing tuberous Drosera?

Sure! When the tubers go into dormancy do not dry out immediately but rather
gradually dry out over an eight week period. This is because as the stolon
gradually dies back to the tuber the tuber is exctracting the energy from the
stolon and will continue to increase in size.

Repot every 2 - 3 years as each year the tuber tends to re-form at a lower lever
to the previous one. If you leave it too long the tuber will be at the bottom of
the pot and will quite likely rot through being over wet. Some species will also
form additional tubers via new dropper shoots from the parent plant.

If you find a tuber fails to reappear do not assume the plant is lost.
Occasionally the tuber will fail to send up a new stolon but will form a new
tuber over the original one. This is a particular problem with newly acquired
tubers and may be due to unseen damage to the growing point. If a plant fails to
appear it is always worth investigating carefully by uncovering the tuber. If
this appears to be happening simply keep the tuber wet for 5 - 6 months and then
dry out as normal. Hopefully the plant will grow normally in the following
season, although I have known tubers which fail to reappear for seveal years on
end. Perseverence helps in the end. :-)

> Thanks in advance to the help!

No problem. If you need any more advice do not hesitate to email me direct.

-- 
Phil Wilson
(cp@pwilson.demon.co.uk)



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