Crispy brown leaf tips are one of the most common houseplant complaints, and one of the most misdiagnosed, the damage looks nearly identical no matter which of several unrelated causes is behind it. The tip itself never recovers once it's browned, but figuring out the actual cause stops new leaves from following the same pattern.
The five real causes
1. Low humidity
Indoor heating in winter can drop relative humidity into the range of 10–30%, well below what most tropical houseplants evolved with. This is the single most common cause, and it shows up especially on humidity-sensitive plants like calathea, prayer plant, and Boston fern. Misting the leaves gives a brief bump that fades within minutes and isn't a real fix, a humidifier, a pebble tray, or grouping plants together to raise the humidity around them all work better because the effect is sustained rather than momentary.
2. Tap water chemicals
Fluoride and chlorine, both common in municipal tap water, can accumulate in leaf tissue over time in sensitive species, spider plant, dracaena, calathea, prayer plant, and peace lily are the usual suspects. This shows up as a fairly narrow band of browning right at the tip that creeps inward gradually. Letting tap water sit out overnight lets some chlorine evaporate; switching to filtered, distilled, or rainwater removes fluoride as well, which plain sitting doesn't fix.
3. Fertilizer salt buildup
Unused mineral salts from fertilizer accumulate in the soil over repeated feedings, and excess salt draws moisture away from root tissue rather than helping it in. This version of brown tips often comes with a visible white or yellowish crust on the soil surface or pot rim, a fairly reliable tell that separates it from the other four causes. Flushing the pot with a thorough water pass, letting it fully drain, clears built-up salts.
4. Inconsistent watering
Swinging between bone-dry and heavily saturated stresses a plant's ability to regulate water in its tissue, and tips, being the farthest point from the roots, often show the damage first. This is different from a single dry spell; it's the repeated whiplash between extremes that does it. A steadier rhythm, checking soil moisture before watering rather than on a fixed schedule, addresses this directly.
5. Cold drafts or heat sources
A spot near a drafty window, an exterior door, or directly beside a heating vent or radiator puts a plant through repeated temperature swings that dry out leaf tissue unevenly. The fix here is location rather than watering or feeding, moving the plant a few feet away from the draft or vent is often enough.
What doesn't cause it
A few older leaves with brown tips on an otherwise healthy, actively growing plant isn't a crisis. It's often just normal aging on the plant's oldest foliage, especially on fast growers. It's worth actual attention when new growth keeps emerging with the same damage, since that points to an ongoing cause rather than one leaf's history.
What to do with existing brown tips
The brown tissue itself won't turn green again, but trimming it off with clean scissors, following the leaf's natural pointed shape, improves the look without harming the plant, cutting straight across a naturally tapered tip tends to look more obviously "trimmed" than following the leaf's existing shape. Fixing the underlying cause is what stops it from recurring on the leaves that come in next; the trim is purely cosmetic.