Problems With a Large Dracaena Plant

Light and Water

• Grown indoors, species like corn plant (Dracaena fragrans), dragon tree (Dracaena marginata), Janet Craig compact (Dracaena deremensis "Janet Craig"), pleomele (Dracaena reflexa) and narrow-leaved palm lily (Cordyline stricta, syn. Dracaena strica) benefit from bright indirect light but do not tolerate strong direct sun. Both direct sunlight and low humidity produce yellowed, withered leaf margins and tips. Augment low humidity with regular spray-misting. While dracaenas require ambient humidity between 30 and 40 percent, well-drained soil should be allowed to dry out slightly between waterings. Dracaenas are fluoride-sensitive, so watering with bottled water or letting tap water sit overnight helps maintain plant health.

Soil and Fertilizer

• Dracaenas require well-drained soils but you should avoid relying on large amounts of perlite for drainage. Because of fluoride sensitivity, you should also avoid using superphosphate fertilizers on dracaenas. A balanced slow-release houseplant fertilizer is your best remedy against the dry, scorched or brown-streaked leaves that signal stress.

Disease

• Reddish or tan spots with yellow halos, usually found close to the bases of leaves, indicate fusarium leaf spot. This is usually caused by overhead watering. Severe cases may require application of a fungicide like thiophanate methyl. Soft rot also produces brown leaves, but leaves are limp and collapsing. Plants have a foul odor. Dispose of plants showing soft rot. Mites and sucking insects that commonly afflict many kinds of houseplants occasionally attack dracaenas and can be treated with insecticidal soap.
  Dracaenas are cold sensitive, growing best in daytime indoor temperatures around 70 degrees Fahrenheit and nighttime temperatures of 10 degrees F lower. Suspect drafts if a dracaena seems suddenly stressed with no specific symptoms.

Pruning and Propagation

• The stems of indoor dracaenas can be cut back as needed to control height or volume, but, on older single-stem varieties, the results may be unattractive even after regrowth begins. Large, mature plants may be better replaced with new, smaller versions grown from cuttings. A cut stem will begin to root within a month in damp sand or potting soil. Cuttings can also be rooted in clear water, then transferred to potting soil. Since plants often do not branch out, a good way to create a bushier plant is to plant several rooted cuttings in the same pot.