Dear Orchid Doc:

My dendrobium plants have been lush and healthy in their home under a mango tree for some time. I have recently noticed however that the tips of the canes have yellowing leaves and they seem to be soggy at the top, even though the stems in the pot are firm and solid.

On a few occasions I have been able to lift out the rotting leaves from the tip, but I notice a sour smell.

I actually had to cut a stem in an effort to stop the rot from spreading to the lower part of the stem and the roots.

What can I do to protect the plants?

Help,

Tinag

Dear Tinag:

Have you been using a fungicide or insecticide on your orchid? Some people don’t for a long time and seem to think that they are not having any problems. However, constant heavy rains will cause the plant to start rotting.

You might have just been watering too late in the evenings.

Cut the cane slantwise so the excess water will run off.

Apply candle wax to seal the wound.

Ensure you use a fungicide once per week for about 4-6 weeks.

Rodomil comes to mind.

Dear Orchid Doc:

Help! My orchids are sick. The undersides of the dendrobium leaves are dark brown and won’t rub off. Please tell me what to do.

J P

Dear JP

You seem to have what is known as orchid rust.

Please use two teaspoons of Topsin with one teaspoon of Caprid in a gallon of water.

Spray once per week, preferably when it is cool (the sun will cause the chemical to burn) for 3 – 4 weeks. At the end of this period, spray once every two weeks for two months, then return to your regular routine.

Your plants should start getting better within four weeks. The old rust will not come off the leaves unless you pick them off, but the new shoots should be rust-free.

Betty Stephenson Ashley

Orchid Cottage

12 Norbrook Drive

Kingston 8, Jamaica .

Cell # 876-3224585,

Fax 876-931-8805

bettystephensonashley@gmail.com