Question

N. gymnamphora  

N. Ventrata   Hello Jeff and Jacob

I have written before. I live in New Mexico in the high desert mountains.

I have a number of nepenthes that are growing indoors in clear tented enclosures. A few of them that are showing some browning and leaf damage that have me baffled.

They were growing fine over the past couple of months, but over the last week I noticed the leaves were turning a reddish brown and curling on the new growth.

The first photo is my N. gymnamphora that has been growing in bright early sunlight for a few hours, and then dappled indirect and artificial light for an additional 6 to 10 hours. During the day they are exposed to temperatures of 80 to 90 degrees and 50% to 80% humidity. At night, the temp drops to 70 degrees with a humidity range from 75% to 90%. The enclosures are big, 6'h x 4'w x 2'd. the temperature is controlled by a thermostat and small ventilator fans.

Three of my plants growing in the enclosure have this problem. The second photo is of a N. Ventrata with a hard scabby brown material (fungus?, that doesn't scrap off the leaf. The leaf edges are curling inward. I have two with this type symptom.

All my plants are growing in a soil mix that you recommended for nepenthes, with the addition of fine fir bark chips mixed in. Most of the plants have been growing in this mix for several months. The soil is kept moist and well drained (no trays, and watered with distilled, RO-mixed with distilled, and rain water. I do mist them in the morning with distilled water, to help with keeping the humidity up during the day.

Is this damage caused by light, air circulation, or is it something else.

Thank you

John

Answer
Hi John,

This looks like you have Thrip damage.  Thrips are a common pest on Nepenthes and are tiny and very hard to see.  If you take a hand lens and examine the plants you may see a tiny, long, thin bug moving about your plants.  You can treat them with a systemic insecticide such as Bayer 3 in 1, or since your plants are in an enclosure, a No-Pest strip would be very effective also.  The No-Pest strips are found in most stores where they sell insecticides.  They have a yellow wax strip that sits in plastic holder and vapor release insecticide.  I don't like to use them where people will be, but in an enclosed space they work super well without the need to spray the plants.  If you prefer not to go that route, spraying will do the job just fine.  Here's a link to our insecticide podcast:  http://www.youtube.com/watch?v=lbRCdJ8ZNF0

Good Growing!

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