Nepenthes Seedlings Turning Brown?

[ramdacc]

I've germinated several different species of Nepenthes (all lowland) the past few months and most of them seem to be growing pretty well but I've noticed some are turning brown, starting at the tips of the tiny pitchers, and slowly the brown begins to work it's way down the the base of the leaf and then eventually the entire plantlets turn brown and die. Whats odd is that little plantlets seem to be doing fine until the 2nd or 3rd pitcher.

Here's how they are grown:
Lights: About 8" below bright flourescent lights. 6500K 75 CRI 3050 Lumens - 16 hours a day
Temps: Between 80 - 90F all day
Humidity: Around 80%+ The pots they are growing in are inside plastic bags with only a small bit of one end open to keep the humidity below 100% and to keep the temps down.
Night Temps: Around 75F, samehumidity level.
Soil: 100% peat - kept moist but not soggy or water logged.
Ive used no fungicides, pesticides, or fertilizers.
Watering with distilled water

The ones that seem to be having the most trouble are my rafflesiana seedlings but all of the species I am growing seem to be having at least some mortality rate.

What would you suggest I do differently?

 

[Safety Shears]

i'd point my finger at either the all-peat soil mix, or a combination of that and not enough lighting. 3050 lumens of 75 CRI at 8 inches doesn't come out to a whole lot of light, but that alone wouldn't cause the browning pattern you're seeing. I'd suggest a soil with equal parts peat and perlite or a shredded sphagnum soil and somewhere around 6,000 to 10,000 lumens of light. everything else looks good though. couldn't hurt to give a really good look around for pests too. anyway, good luck to you.

 

[GrowinOld]

Just for general information...
Usually when a plant starts browing from the tips, it means the plant is too dry, the humidity too low, the temps or lighting too high/too much.
When a plant starts browing from the bottom of the leaf or inner parts of the plant, it usually means that the plant is too moist, cool or kept too dark for conditions, leading to rot from the plant or roots, moving on to the leaves.

As far as your situation, I really can judge specifically what the problem is.
The real way to learn how to grow any plant, is to understand what it is telling you, and then figuring out how to correct the situation.

Perhaps part of what I have mentioned here will help you to decide what condition to change/alter.

We all have slightly different situations, so things are not always as simple as reading figures & doing "this or that".
What works for me may not work for you.
I would suggest looking at your conditions & deciding what may be off enough to cause this.

In the past, when doing Neps from seed, I had to increase humidity when I moved them to a location with brighter lamps. As they grew bigger,
I moved them to a bigger location, which provided slightly different environmental conditions.

Good luck with this. Perhaps someone else here has other suggestions also.

 

[Exo]

I've seen this....comes from using a media that is either too acidic, too dense, or to rich in nutrients....I find it happens most often in pure peat after it gets severely decomposed.


So far I've gotten my best results from milled sphagnum mixed with a bit of really fine perlite or pumice, it seems to have the right balance of moderate acid and drainage.

 

[ramdacc]

The media was my first concern as well. It was bought from Lowes several months back and has set outside in the elements. It is pure sphagnum peat but I'm not sure where it comes from. It's the Magic Earth brand.

 

[Whimgrinder]

Peat should always be "washed" before you use it to leach out any salts or (gawd forbid) fertilizer added to it by the manufacturer. (It seems many do this nowadays, ugh). So, you soak your peat in clean water overnight, wring out as much as you can, and repeat the process one or two more times. Although there are precious few references to Magic Earth brand Peat, it does appear this brand adds fertilizer to their soil mixes, so I wouldn't be surprised if this happens with the peat also. Such products are best avoided entirely, rather than trying to render them usable for CPs. Peat isn't ideal for Nepenthes seedlings anyway, since it tends to start out acidic and increase in acidity over time, and seedlings are very sensitive to strong pH. Better to finely chop LF Sphagnum. Thats what I do, and it supports seedling growth beautifully. (I wash sphagnum before using it as well)