Problem with plants in bog garden (possibly fungal?)

[lochness]

Hello fellow members of the ICPS forum. I've been growing carnivorous plants on my windowsill and in a small 10 gallon terrarium for over a decade now without any problems. I am located in Clinton, Tennessee if that helps with climate information (Zone 7a/6b depending on who you ask). Two years ago I built a small bog garden (3 feet diameter, 18 inches deep). In it I planted my then ten year old Sarracenia purpurea, my eight year old S. x 'Judith Hindle', and some eight year old Drosera capensis, along with some plants that I bought that year: a Sarracenia leucophylla, Sarracenia psittacina, Drosera binata, Drosera rotundifolia and three cultivars of Dioneae muscipula.

The plants grew remarkably well, so this spring I bought and added a Sarracenia flava. The S. flava did not grow well, only sending up two leaves which quickly dried up. When I uncovered the rhizome, I noticed that one end was brown and dying and that the base of the leaves were also becoming brown. My internet searches fairly convinced me this was botrytis (we had a cool, very wet spring and summer this year). The only other plant that appeared to be affected at the time was the S. leucophylla, which I was able to save by quickly dividing it and cutting off all brown material on the rhizome (replanting it in a small container to quarantine any missed infection). The S. flava appears to have been lost completely. The other plants appeared unharmed, and most grew as well as I expected with our less than ample sunlight. They never showed any wilted or dying leaves. I did almost lose the D. binata immediately after it flowered, but it recovered on its own so I believed it to just be flowering fatigue.

However, today I noticed the same wilted and dying leaves on my S. purpurea and S. psittacina. The bases of the leaves turn brown, and the rest of the leaf dries while still green. These are photos of the afflicted plants and leaves:

Sarracenia purpurea (notice how much it has divided, this was two small plants a foot apart a year ago)


S. purpurea leaves


S. psittacina (again, very many crowns formed this year).


S. psittacnia leaves


Dioneae muscipula typical, possibly affected


I'm sorry I do not have photos of the rhizomes, I did not discover this until this evening and it was already getting quite dark. I can try to get photos of the rhizome tomorrow if it is necessary.

Can anyone confirm whether this is a botrytis infection? If it is (or isn't), what do I need to do to save my plants, or are they in any real danger? I do not have a greenhouse, and our basement is very dark and generally too warm for dormancy (50F up to 60F, sometimes dropping to near freezing, and the temperature swings can be rapid). I am worried about emergency division and cutting interfering with dormancy and cold tolerance this late in the year. East Tennessee winters are generally mild, but they are very unpredictable and cold snaps below 0F are rare but not unheard of.

Any help and advice would be greatly appreciated, as I care very much about these plants.

[stevebooth]

Hi Lochness, sorry to see the trouble you are having.
I presume that the plants havent been subjected to a sudden influx of nutriens and have been watered with rain water or similar.
I have seen similar damage from nutrient or foliar feed on the leaves, but as the rhizome looks to be rotting prior to the leaf damage showing, it sounds like it could be fungal perhaps Cylindrocaldium rather than botrytis, in which case I know nothing more than isolate teh plants (shouldnt be difficult if they are outside and in a container) and treat with fungicide such as systhane and hope.

Sorry I cant be more definite, perhaps someone else on the forum with knowledge of pathogens can help more
Steve

[peterhewitt]

Yes, this is almost certainly root rot of some kind, you will have to remove affected plants and a lot of the media around them, divide them up and discard all rotted material, dip divisions in a ten percent bleach solution for a few seconds and then rinse and re plant. And hope for the best. Fungicides might work to alleaveate the symptoms but you will still have a whole lot of rotten material in the ground....it will flare up later. It's usually not a good idea to let Sarracenia divide unchecked for too long in cultivation, crowded rhizomes do have a tendency to rot.

[lochness]

Thank you very much Steve and Peter Hewitt for the replies and the info. Though it's not the best news, it is relieving to at least know that I am dealing with a problem I can do something about.

I will definitely try dividing and cleaning the rhizomes of infection and re-potting them separately. As I feared, this involves removing infested media. These are in a bog garden together with several other plants, not in individual pots. Should I assume the entire bog is infested with this pathogen and it would be wise to replace the peat in it/remove the other plants? Or would it be wiser to leave the plants that appear fine alone until spring? I will probably be replacing/moving the bog in the spring, as it was not situated in the best of places concerning light and accessibility.

What worries me about removing them from the bog is providing them with dormancy this winter. I believe that the pots I have are too small to prevent freezing solid this winter outside and there is no protected indoor place that does not get far too warm for them to go entirely dormant (60F is the lowest daytime temperature, night temperatures fall close to outdoor temperatures due to very old heating ducts that we constantly have to re-tape). Would they survive on the windowsill by going into a light dormancy, at least enough to survive until spring? Would dormancy even be necessary for freshly divided plants? I have heard that dividing and replanting is a trick used by some growers to get two or three years of constant growth from some carnivorous plants. I worry very much about dormancy because I lost my first VFT after five years due to not letting it go dormant (the S. purpurea barely survived for four more years, this was what prompted building a bog garden once I could afford to do so). Winters here are generally mild but are unpredictable and sudden cold snaps and long freezes do occur, though rarely.

Are my dormancy concerns justified, or am I just gun-shy?

[stevebooth]

The safest way would be to assume that the bog is entirety infested, remove all the peat mix (careful how you dispose of it) sterilise the container, plants, plant roots and start again I’m afraid.
Tricky one with the dormancy, there are several ways of looking at it, either you have an already weak plant that if you skip dormancy will try to continue to try to grow in less than ideal conditions (unless you put it under lights and in warmth) thereby possibly weakening it further leading to its eventual demise, or you let it go dormant outside with the attendant climate problems. An alternative would be fridge dormancy but the shock of bare rooting it, the sudden temperature drop and lack of natural light wouldn’t help a poorly plant much. By the sound of it, probably, the better option would be to redo the bog, mulch it (but don’t stifle all ventilation) and over winter outside, as the plants have stopped growing now they will only need the roots to absorb enough water to counter act the effect of the desiccating winds. Is the bog in the ground or a container? If it is a container you will probably have problems with freeze and thaw cycles unless you can insulate it in some way.
Good luck
Steve

[lochness]

The bog is in the ground, 18 inches deep and 3 feet diameter. The bottom six inches were dug through shale rock which I covered with clay from the upper portion of the hole to try to prevent tearing the plastic as much as possible, and a layer of sand on the very bottom. It's lined with a layer of 6 mil plastic sheeting which has degraded above-ground and will need to be replaced if I remove the media. I have an east-facing window that my terrarium is currently in that I could try to grow the plants through the winter, it usually doesn't get colder than 45F there. I'm just not sure whether it would be more of a struggle for the plants to try to grow through the winter, or for them to try to survive the cold.

[taz6122]

You could always give them a bare-root refrigerator dormancy and replant in fresh media come spring.