Carnivorous Plants/Saracenia browning growth
Hi, i have been growing mostly sarracenia outdoors in the Uk in bogs about 30 square feet each, in 50/50 mix peat and perlite for about twenty odd years. This year one of the beds, in spring suffered some form of die back, where the some of the phylodia turned brown and dry. I initially diagnosed this as drying winter winds desiccating the plant leaves. the other beds didnt suffer but I just thought that the one bed had had worse exposure than teh others.
Now some of the plants have made pitchers which have similarly turned brown. the plants have never dried out, not been fertilised, sprayed, or had any minerals anything that
would cause this sort of dryness. But on the same plant there are (reasonably) healthy leaves!. I am afraid it is an infection that may spread to the rest of my collection, which would be a bit of a disaster.
Picture enclosed, you will see the brown leaves and green pitchers on the same plant.
I did put some sulphur on it last year to acidify teh soil and dug into the top few inches some pine bark and peat as the soil was looking 'tired', something I have done before without detrimental effect
Any idea what is causing it? and if so how I can tackle the problem.
Thanking you in anticipation.
This looks like you have some kind of fungal infection going on here. It looks like some of the Sarracenia are having a root rot going on, killing growing leaves.
Here's what I recommend. Dig up any infected plants. Cut/peel off all dead or dying leaves, then cut off any brown, mushy parts of a rhizome. Keep doing that until you get to clean, white rhizome. At that point I would replant the healthy part in a pot, and give it a year to recover. If you have some fungicide spray it would be good to spray the rhizome piece before potting. If you find there is little to no unaffected tissue, then the plant is a loss; it would have died anyway.
Next, get into the bog garden and really clean it up. Remove any dead leaves or leaves that are looking bad from aphid attack, etc... The goal is to open up the area to more sun and air circulation. I would remove some of the soil in the area where there were infected Sarracenia, and replace it with fresh peat mix. Mixing in some powdered sulfur like you did is a good idea to help inhibit fungus. I would leave that area fallow for now, or plant different species there such as sundews or flytraps. It's always an option to just redo that whole bed also, but I know that is probably a big job.
This type of Sarracenia disease is usually caused by Botrytis, and frequently occurs on plants with thickly massed rhizome heads. The lack of light, and air circulation encourages the growth of the mold on any weak or damaged areas of the rhizome. Plants most prone to it are S. rubra types and S. purpurea venosa. Getting more sun and air in there should really help.
This should help, but let me know how it goes.