{"id":26827,"date":"2026-06-06T05:48:00","date_gmt":"2026-06-06T12:48:00","guid":{"rendered":"https:\/\/extension.wsu.edu\/yakima\/?p=26827"},"modified":"2026-06-04T15:01:57","modified_gmt":"2026-06-04T22:01:57","slug":"why-do-plants-have-scents","status":"publish","type":"post","link":"https:\/\/extension.wsu.edu\/yakima\/2026\/06\/06\/why-do-plants-have-scents\/","title":{"rendered":"Why Do Plants Have Scents"},"content":{"rendered":"\n

by Carol Barany, Master Gardener<\/h2>\n\n\n\n

Humans have delighted in the scents of flowering plants since the beginning of time, but flowers don\u2019t smell good to please us.  It\u2019s  insect pollinators they\u2019re trying to bewitch.  The very survival of flowering plants depends on it. <\/p>\n\n\n\n

It\u2019s all about reproduction.<\/p>\n\n\n\n

Flowers use a combination of visual cues like vibrant colors, distinct shapes, invisible ultraviolet patterns, and structural \u2018runways\u2019 or \u2018landing pads\u2019 to guide pollinators to a pollen and nectar reward. While visual cues help pollinators find flowers, thousands of plant species evolved to produce scents, indicating that visual cues were not always enough to get the job done. <\/p>\n\n\n\n

No two plants produce the exact same scent, yet pollinators can discriminate subtle differences in this vast array of aromas. Scientists have catalogued 1,700 different scent compounds produced by flowers.  Some flower fragrances are composed of more than 200 different compounds. <\/p>\n\n\n\n

Plants that rely on pollination by bees or butterflies have relatively sweet scents, and their flowers emit the highest scent levels during the daytime.  Plants pollinated by moths or bats produce the highest scent levels at night, when those animals are actively seeking food sources, and visual cues are hidden in the darkness. <\/p>\n\n\n\n

Many flowering plants are \u201cgeneralists,\u201d emitting scents that appeal to a wide variety of pollinators. On the other hand, the Darwin\u2019s Orchid emits a distinct fragrance that attracts only the giant sphinx moth, which evolved a remarkably long proboscis to reach this particular flower\u2019s nectar. <\/p>\n\n\n\n

Flowers walk a fine line in scent production. On the one hand, enough scent must be produced to lure pollinators to fertilize their flowers. On the other, they don\u2019t want to over do it and waste the valuable and limited stored energy supplies that scent production takes. To be most efficient, most flowering plants time their scent production to coincide with when the maximum amount of pollen is available in their flowers. Mature flowers release more intense scents than young flowers, but later pull back and reduce the quantity and quality of their fragrance.  This directs other pollinators to move on to new flowers, increasing the chances of successful reproduction.<\/p>\n\n\n\n

The Titan arum (Amorphophallus titanum<\/em>) is an endangered plant native to the rainforests of Sumatra, Indonesia.\u00a0 Like other flowering plants, the titan arum uses scent to attract pollinators when it\u2019s ready to reproduce. Calling this arum a \u2018Drama Queen\u2019 is an understatement, for sure. \u00a0<\/p>\n\n\n\n

\n
\"Titan<\/figure>\n\n\n\n
\"Titan<\/figure>\n\n\n\n
\"Titan<\/figure>\n<\/figure>\n\n\n\n

It can take up to 10 years for the Titan arum to produce the largest inflorescence in the plant kingdom which can reach 12 feet in height. A leaf is produced each year from the corm which absorbs and stores energy from sunlight. When enough energy has been stored to produce a flower bud, Titan arum will attempt to reproduce. At bloom time, the arum’s corm can be larger than a beach ball and weigh more than 200 pounds.  If all systems are \u201cGO\u201d, the spiky spadix emerges from the ruffly spathe at a rate of 4-6 inches each day. A spadix is a botanical cluster of many tiny and tightly packed flowers arranged on a thickened, fleshy central stem. It is often enveloped by a hooded bract called a spathe. <\/p>\n\n\n\n

About two weeks into the process, growth slows, and the spathe begins to open. Botanic gardens around the world with a Titan arum in their collection have live-streamed this event to thousands of plant aficionados eager to witness something truly extraordinary.  <\/p>\n\n\n\n

Unlike most flowering plants, the arum has enough stored energy to pulse out its scent in one big burst. It\u2019s not a smell you might expect.  Carrion beetles and flesh flies are the titan arum\u2019s natural pollinators.  To get their attention, the arum produces a scent that that has been described as decaying, rancid, rotten flesh wrapped in a dirty diaper. It\u2019s enough to attract insects an acre away. Drawn to the scent of something dead to lay their eggs on, the beetles and flies deposit pollen carried on their backs and bodies from the last flower on the inflorescence they visited and complete the act of pollination in a single evening.<\/p>\n\n\n\n

Next time you bury your nose in a big bouquet of florist roses and smell, quite frankly, not much, blame it on commercial rose breeders. Scent genes were often sacrificed in the drive to produce longer-lasting stems, vibrant colors, and sturdy petals that survive long distance shipping.<\/p>\n\n\n\n

But next time you bury your nose in a bouquet of home-grown lilacs, lilies, or sweet peas, thank the natural co-evolution of flowering plants and insect pollinators for the magnificent achievement of those gorgeous scents.  <\/p>\n","protected":false},"excerpt":{"rendered":"

by Carol Barany, Master Gardener Humans have delighted in the scents of flowering plants since the beginning of time, but flowers don\u2019t smell good to please us.  It\u2019s  insect pollinators […]<\/p>\n","protected":false},"author":210,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_tec_requires_first_save":true,"_wsuwp_accessibility_report":null,"_EventAllDay":false,"_EventTimezone":"","_EventStartDate":"","_EventEndDate":"","_EventStartDateUTC":"","_EventEndDateUTC":"","_EventShowMap":false,"_EventShowMapLink":false,"_EventURL":"","_EventCost":"","_EventCostDescription":"","_EventCurrencySymbol":"","_EventCurrencyCode":"","_EventCurrencyPosition":"","_EventDateTimeSeparator":"","_EventTimeRangeSeparator":"","_EventOrganizerID":[],"_EventVenueID":0,"_OrganizerEmail":"","_OrganizerPhone":"","_OrganizerWebsite":"","_VenueAddress":"","_VenueCity":"","_VenueCountry":"","_VenueProvince":"","_VenueZip":"","_VenuePhone":"","_VenueURL":"","_VenueStateProvince":"","_VenueLat":"","_VenueLng":"","_tribe_blocks_recurrence_rules":"","_tribe_blocks_recurrence_description":"","_tribe_blocks_recurrence_exclusions":"","_external_link":"","_expiration_date":""},"categories":[14],"tags":[65],"_links":{"self":[{"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/posts\/26827"}],"collection":[{"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/users\/210"}],"replies":[{"embeddable":true,"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/comments?post=26827"}],"version-history":[{"count":3,"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/posts\/26827\/revisions"}],"predecessor-version":[{"id":26833,"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/posts\/26827\/revisions\/26833"}],"wp:attachment":[{"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/media?parent=26827"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/categories?post=26827"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/extension.wsu.edu\/yakima\/wp-json\/wp\/v2\/tags?post=26827"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}