Expert: Sarracenia Northwest - 10/14/2010

Question
Hello I bought a N. reinwardtiana and I live in New York City Right now i have
the plant along with 5 other Nepenthes plants  under four 23 watt compact
flourecent bubs with a small fan on the side curculating air .I sprayed it with a
sulfur fungicide ( i used the powder form 90% sulfur and mixed 1 teaspoon
per gallon) because i saw red dots on the leaves, is this fungus or mold. How
long wil it take for it to go away. Also would it spread to my other plants.

Answer
The red dots are commonly called rust spots.  It's a harmless fungal infection, but it can be a sign that something isn't quite right with the growing conditions.

If the spots are small and fairly uniform in size and shape, they may have been caused by a pest.  When the pest bites into the leaf, that area of the damaged leaf is prone to fungus; hence, rust spots.

Another factor could be the temperature being too cold or the lighting not being bright enough.  Both situations can make a plant prone to rust spots.

Once the damage is done, you can't get rid of the spots.  The discoloration is permanent.  The only thing you can do is to prevent new ones from occurring.  If you suspect a pest, spray your plants with an appropriate insecticide.  Watch our video on the subject:
http://www.cobraplant.com/videos

The sulfur is fine to prevent new rust spots from occurring, but you may need to spray weekly or monthly.

Good growing!
Jacob Farin