Dracaena brown spots
I have a Dracaena plant that I've had for 11 months in the corner of the room (north facing). This is a replacement plant as the prior one had white spots that would not go away. After contacting the local supplier of the home improvement store, it was replaced. This new one has developed spots on the ends of the leaves and within the leaves. I have read some articles online but wanted some local, experienced advice. Is there anything I can do to correct this matter?
Based on your photos it looks like the plant was subject to a leaf spot. Sometimes this can come in with the plant. All you can do is cut off the affected leaves and focus on proper care. Make sure the plant is not located next to heating or air conditioning vents.
Even though they tolerate low light, the plant benefits from bright light but not in direct sunlight. The best spot is one that gets 2 to 3 hours of sunlight filtered through a blind or curtain. Normal room temperatures should be about 65 to 75 degrees. High humidity is necessary so keep the air moist by standing the plant on a tray or saucer of moist pebbles and by occasionally mist spraying the foliage. During the winter months, water to make the potting mixture barely moist and allow the top mixture to dry between waterings. Make sure the pot has good drainage. During the active growth period, keep the potting mixture moist but do not allow the pot to stand in water.
Dracaena is very sensitive to fluoride in tap water. Symptoms include yellowing of the tips or margins of the leaf or dead, scorched areas. You can use distilled water to water the plant. Fertilize during the active growth period only.
See the following link for more information http://www.clemson.edu/extension/hgic/plants/indoor/foliage/hgic1504.html