Question

Ailing Cape Sundew   QUESTION: I have been having trouble with a cape sundew. It was growing well, but then
the new leaves started to form in a stunted manner, never fully developing
and with the tips turning brown. I did not see any signs of insects but at your
prior suggestion I started treating the plant with neem-based insecticide.
This did not help, so I then tried your other suggestion of clipping off the
plant at the roots. It grew back well at first, but then the stunted growth
reappeared. I tried repotting (soil mixture is  2 peat, 1 perlite, and 1 washed
sand); this also helped for a while, but eventually the problem returned. I use
only distilled water, and have the plant indoors under artificial lights (Would it
be helpful to move this plant outside for the summer?  I am in the Portland
area). I should mention that the plant came potted together with a tropical
bladderwort. When I repot, I notice that the bladderwort roots fill a significant
portion of the pot. Could this be causing a problem?  Any advice you can
provide will be appreciated.  Thank you.

ANSWER: Hi Robert,

I remember talking to you about this problem.  I've looked at your photo for quite some time and I'm a little baffled.  You plants look chlorotic like when their is a nutrient problem, or if plants are kept in a very hot greenhouse in very bright exposure.  However, I noticed that all of your plants are very pale; almost no red at all.  This is usually a sign of low light.  Yet, in low light Cape sundews usually curl their leaves under.  I feel like clues in this mystery are missing.

What was the brand of soil ingredients?  Fertilizer present could produce some of these symptoms.

Tell me more about the lighting.  What types of lights?  How close are they to the plants?  How warm is it in the growing area?

How are you watering the plants?  How deep do the pots sit in water?  Is the pot the Cape Sundew is in undrained, or does it have holes in the bottom?  Do you top water, or just from the trays?  Also, do you live right in Portland?  Do you know if you are on the Bull Run water system?  If you're not, your water may have more minerals than is desirable.  Low light combined with hard water could make plants look like this.  You mentioned they looked better for a little while after transplanting.  This would be consistent with hard water, or minerals in the soil.

If we can unravel this one, it will be helpful for you and lots of other people also.

Looking forward to hearing from you.


Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com

---------- FOLLOW-UP ----------

QUESTION: Jeff,

Thanks for your reply.  First, let me answer your questions:

What was the brand of soil ingredients?
(1)   Peat moss was Black Gold Canadian Sphagnum Peat from a large bale
(But in the past I have used the small bags of peat moss, available at Fred
Meyer.  I noticed in the FAQ that you advise against using these; what is
wrong with them?)
(2)   Perlite was Whitney Farms brand, purchased at Fred Meyer.
(3)   Washed sand was also Whitney Farms--in a small bag purchased at Fred
Meyer.

Tell me more about the lighting.  What types of lights?
I am using several 13-W fluorescent plant lights.  I know from reading your
FAQ that you think these are inadequate and I was planning to upgrade to
brighter lights.  I was going to ask this as a separate question, but since it
came up here, I抣l pose it now: You recommend 40-W fluorescent bulbs, but a
48" fixture is not convenient for me (The plants are on shelves 36" long).  A
36" or 24" fluorescent fixture would work, but I did not see any 40-W bulbs
commonly available in these lengths.  Are there shorter bulbs that would
work?  It seems that matching the luminance (brightness) would be more
important than the wattage.
I should also mention that the shelves on which these plants sit are next to a
south-facing window, so the plants receive a fair amount of sunlight in
addition to the artificial lights.

How close are they to the plants?
When I recently repotted, I put the main plant in question in a taller pot (You
can see from the photo), so it is about 4" from the bulbs.  A second plant,
which grew from a piece of root that I inadvertently broke off during a
previous replanting, is in a shorter pot (You can see it in the background),
about 6" from the bulbs.

How warm is it in the growing area?
Normal indoor temperature in my house.  As I mentioned, this particular
room has a south-facing window, and so is perhaps a little warmer than
other rooms because of the greenhouse effect.

How are you watering the plants?
Mostly from the trays, but occasionally from the top, especially for the plant
in the taller pot.  Occasionally I will mist them as well.

How deep do the pots sit in water?
I fill the tray to about 2" deep and then let it drop to about ? before refilling.
Is the pot the Cape Sundew is in undrained, or does it have holes in the
bottom?
It has a hole in the bottom for draining.

Do you top water, or just from the trays?
Answered above.

Also, do you live right in Portland?  Do you know if you are on the Bull Run
water system?  If you're not, your water may have more minerals than is
desirable.  Low light combined with hard water could make plants look like
this.
I live in Vancouver, WA and use only store-bought distilled water.

You mentioned they looked better for a little while after transplanting.  This
would be consistent with hard water, or minerals in the soil.

I had a thought while I was waiting for your reply: I have several plants in a
common water tray.  In addition to the cape sundews, I have some other type
of smaller sundews that came in the same pot (now replanted to their own
pots), some D. Adelae, and also some butterworts (which are growing VERY
well).  The butterworts?soil mix is different, containing things like vermiculite
and lava rock.  If the sundews are particularly sensitive to minerals, could it
be the case that minerals are leaching out of the butterwort soil into the
common water tray and poisoning the sundews?  That would seem to be
consistent with the initial vitality of the sundews immediately after repotting,
followed by a steady decline.

While we抮e trying to sort this out, I have repotted the plants again and
isolated the watering tray.  I also placed them out on the deck in the full sun
until I determine what would be a suitable artificial light.

Thanks again for your help.  By the way, I am looking forward to buying your
e-book if and when you ever get around to releasing the Mac version.

Answer
Hi Robert,

Thanks for giving such a detailed response.

I think all you soil ingredients are fine.  I've not had any trouble with the Whitney farms brands.  The reason we advise against the small bags of peat is that Scott's Miracle grow is a practical monopoly in the retail soil market.  They put fertilizer in all their products including single ingredients such as peat moss and perlite.  We've had many a customer that has lost their plants via Scott's or Miracle-gro peat moss.  I even wrote them about this issue, and they gave me the typical multi-national corporate patronizing response.

Being in the same water trays as the butterworts is unlikely to be causing the problems.  We don't recommend vermiculite for sundews, but from our own experiences in our greenhouse, it doesn't release enough minerals to be problematic.  We have sundews in butterwort trays with no problems.

Your butterworts looking good I think is the missing clue here.  The light levels are too low.  They are fairly shade tolerant, the sundews are not.  If your bulbs are the type of 13w fluorescent tube I think they are, and if they are plant spectrum tubes, they are not bright enough.  The plant spectrum tubes have a lower lumen ouput, and these are the same types used on aquariums.  They don't have a very high output.   Combine that with them being 4-6 inches away; not bright enough.  We usually keep ours within 2 inches of the plants.   When we recommend 40 watt tubes for 48 inch fixtures it's because many "energy-saver" type tube are out there such as 24 and 32 watt tubes.  They have a significantly lower lumen ouput.  You are correct in lumen output being the important factor.

Here's what I think you can do.  I've seen some nice 24", two-tube fixtures.  See if you can find those.  Use cool-white tubes of the highest lumen output you can find.  Try to get your plants within 3 inches of the tubes.

With your water, try to keep the water level a little lower for the present time.  Have only about an inch in the trays, and let it go dry before adding more.  Don't let pots dry out, but this will minimize fungal problems during recovery.

Since your plants are now outside, you may experience leaf burn since they have been in low-light.  Just cut off any leaves that burn.  With the Cape Sundew, cut off most of the leaves except for the plant's crown.  Be sure to leave your butterworts inside.  They can't handle full sun.  If you decide to leave them outside for the summer, they will develop dark red tentacles.

Let me know how it goes.


Good Growing!

Jeff Dallas
Sarracenia Northwest
http://www.cobraplant.com