Question
My d.deremensis rhoersii is 5foot tall with lots of stems and healthy looking and much admired but during the last 6 months its mature leaves mid stem have started to brown at the base next to stem.    This browning spreads all through the leaf affected if left on plant.
I,ve tried more and less watering, I take off leaves affected as soon as any browning is evident hoping to stop the spread if it is fungal to no avail.
The plant is in a large pot of multi purpose compost and I feed it through the summer months with baby bio plant food. It does not get direct sun but the light levels are high as I live in a penthouse apartment with windows on all 4 aspects. It is still growing vigorously and I have taken successful cuttings but the latest "baby" is showing the same problem as the mother plant.  can you identify this problem and is there any cure Please.

Answer
Hi Jean, I do not grow these but found information for you.  kathy

When D. deremensis fertility is too low or when the plant is overwatered, it may develop weak color and narrow strappy leaves.  Lack of phosphorus can cause a severe dieback in the middle and older foliage.  Iron deficiency is common and results in a rather severe interveinal chlorosis, especially in 慗anet Craig?

If you gently grab the third leaf back from the growing tip during the middle of the day and hold it lightly in your hand, you may be able to feel the leaf's heat. If you can, it probably means the light and temperature are too high. You can mist the plant to reduce its temperature and move it away from the light or heat source.

D. deremensis prefer low to medium light.

Pests and Problems

Scale, mealybugs, and thrips are most common.

Root diseases are generally caused by overwatering or sitting in water.  Leaf spots (which sometimes occurs with wilting) on newer leaves can be caused by fungi living in the soil. Aerate the soil and allow the plant to dry down.  Clean any tool used on diseased plants to prevent the spread of the fungus.

Stem rot, which is also caused by overwatering, may cause a bad odor.

Tip burn develops when the plant is too dry, humidity is too low.  It can also be caused by an accumulation of boron or fluoride, or high soluble salts.

When exposed to too much light, the leaves may become bleached.  Move the plant away from the light source.

Fusarium moniliforme is a leaf spot disease caused by this pathogen often found in Dracaenas.  Leaf spots are round, raised, rust colored lesions with yellow halos.  Off-white spores appear at the growing point where the apex may rot.  Other symptoms include root rot, chlorosis, and wilting.

Phyllosticta maculicola is a pathogen that causes a leaf spot disease.  In Dracaena it is characterized by brown leaf spots with yellow halos.  With P. dracaenae, the spots are irregular, brown with purple borders and yellow halos, and appear on the lower surface of older foliage.

If it is fungus or disease you can use Atomic Grow to cure the problem, and it is organic.