WASHINGTON — A comprehensive federal survey released Tuesday has found that the phrase "pretty hard to kill," applied to an estimated 340 million houseplants sold annually in the United States, has so far proven to be aspirational rather than descriptive, as the plants in question continue to die at a rate researchers are calling "essentially unchanged."

The report, compiled by the National Horticultural Consumer Confidence Bureau, examined plant mortality data across all fifty states and found that the pothos, the snake plant, the ZZ plant, and the spider plant — all broadly marketed as "basically impossible to mess up" — account for 71 percent of all houseplant fatalities recorded last year. The peace lily, whose retail tag assures buyers it will "tell you when it needs water," was found in most cases to have communicated this need and been completely ignored.

"What we're looking at is one of the most consistent gaps between product marketing and consumer outcome that this agency has ever documented, which is remarkable given that we also regulate extended warranties."

Dr. Fenwick Osbaldeston, Senior Fellow for Domestic Vegetation Outcomes at the Potomac Institute for Retail Botany and Applied Negligence, said the findings were troubling but not surprising.

"The term 'hard to kill' was never subject to any regulatory definition," Dr. Osbaldeston explained, speaking from what he described as an office containing eleven dead succulents. "It has functioned essentially as a vibe."

The report further notes that the leading cause of houseplant death is overwatering, the second leading cause is underwatering, and the third is being placed in a room described by the owner as having "pretty good light," which in practice means no direct sunlight reaches it between October and April. A small but statistically significant share of plants died after being repotted into decorative vessels with no drainage holes because the owner found the drainage holes, in their words, "kind of annoying."

Garden center retailers contacted for comment declined to revisit the language on their plant tags. A spokesperson for the National Retail Nursery Consortium, Brielle Tambourines, said the phrase "hard to kill" was "meant to convey a general spirit of resilience" and that the industry stood behind its characterization. She added that the Consortium had recently introduced a new designation — "thrives on neglect" — which market research showed consumers found "very reassuring."

The Bureau's report recommends clearer labeling standards, including the proposed mandatory disclosure: "This plant will survive if you water it on a consistent schedule and place it in appropriate light, which is to say, this plant will not survive."

Congress is not expected to act on the recommendation. Three of the four potted plants in the Senate chamber's antechamber died during the drafting of the report. The fourth is described by facilities staff as "hanging in there," though staff have not watered it since March.