Brown leaves on plant
Hi Extension Experts: I have a question about my houseplant, which I believe to be a dracaena. I inherited the plant back in December. It was in a very small pot, so I repotted it. I started noticing a lot of brown leaves, which I removed with scissors. I cut back significantly on watering, thinking that I was probably overwatering it. I'm still noticing a few leaves with dead tips. I'm not sure if I'm now underwatering, or if I need to switch to distilled water (I've been using D.C. tap water), or if it's a fungus or some other disease. I'd appreciate any suggestions you might have. Thank you!
District of Columbia County District of Columbia
Yes, this is a Dracaena. It is good that you repotted it, as fresh soil can help solve problems of salt (mineral) buildup in the soil, from fertilizer residue and naturally-occurring tap water minerals. Such buildups can be one cause of leaf yellowing and tip browning.
Chlorine, chloramine, and fluoride additives in tap water can cause the same symptoms on sensitive houseplants, of which Dracaena is known to be. You can try switching to some sort of filtered or bottled water, but use caution with the latter as drinking water bottlers often add minerals (including sodium) back into the water to improve taste and make it safer to consume. You can also try distilled water, but using it pure would not be necessary. Diluting your tap water with it should suffice; perhaps by a third or half. Letting tap water sit out overnight can help dissipate chlorine, but it will not remove chloramine or fluoride.
Watering patterns for Dracaena should allow for them to dry out a bit between soakings. They don't want to get completely dry, nor do they want to stay constantly wet either. For this size of pot, feeling the moistness of the soil about two inches down should suffice. Make sure excess drained water does not stay in the saucer so it doesn't re-absorb into the soil.
Diseases are possible causes of leaf damage, but indoors, less common than abiotic (environmental) causes. We do see, however, what might be mealybug residue on the main stems, between the portions of leaf and stem. These sap-sucking insects can stress a plant and also tax its water needs. You can read more about mealybugs and their control here: https://extension.umd.edu/hgic/topics/mealybugs-houseplants. If you find that you do have mealybugs, any topical sprays need to be applied very thoroughly for good control, and a few re-applications will be needed. Pay particular attention to the leaf undersides, the stems, and all the crevices on the plant where the bugs can hide. Read the label on whichever product you choose (make sure it lists indoor/houseplants as plants it treats, so you don't use an outdoor-only chemical by mistake) regarding instructions of how to apply and when to re-apply. You can take the plant outside to spray if you wish; just keep it in shade and make sure it's not needing water when it's treated. You can bring it back inside once the leaves have dried.
Over time, progression of the leaf burning should stop, and while the damaged leaves will not heal, you can remove them as desired as the plant produces new leaves.