Why Go Native?
Asheville GreenWorks and its Bee City USA – Asheville Leadership Committee encourage including as many natives as possible in ornamental landscapes in a continuous effort to bring back pollinators. Here’s why and how.
Pollinator Decline & Ornamental Landscapes
A massive study conducted by the United Nations in 2016 reported that 40% of all insect pollinator species are at risk of extinction due to habitat loss, pesticide exposure, disease, and climate change. Collectively, urban and suburban landscapes have the potential to help reverse pollinator
decline. The key is integrating the indigenous plants that native pollinators have co-adapted with over thousands, if not millions, of years. (The oldest known bee fossil is 100 million years old!) Currently, exotic (non-native) plants dominate most American ornamental landscapes, generally
comprising at least 75% of species. While non-native, non-invasive plant species like herbs, fruit trees, annuals and other plants are attractive and beneficial to pollinators, and are great additions to ornamental landscapes, ideally, those landscapes would contain at least equal numbers of
native species to support a diversity of pollinators.
decline. The key is integrating the indigenous plants that native pollinators have co-adapted with over thousands, if not millions, of years. (The oldest known bee fossil is 100 million years old!) Currently, exotic (non-native) plants dominate most American ornamental landscapes, generally
comprising at least 75% of species. While non-native, non-invasive plant species like herbs, fruit trees, annuals and other plants are attractive and beneficial to pollinators, and are great additions to ornamental landscapes, ideally, those landscapes would contain at least equal numbers of
native species to support a diversity of pollinators.
Pollinator/Plant Co-Evolution
Nearly 90% of all flowering plants rely on pollinators to reproduce and fruit. As we know, timing is everything. Many plants bloom during the time of the year when their preferred pollinator typically emerges, a relationship that serves both the plant and the pollinator. For example, mason
bees emerge early in the spring as fruit trees are blooming and leafcutter bees emerge a little later when more, tender leaves become available. Pollinators like moths and butterflies have co-evolved with their larval host plants (where they lay their eggs) to tolerate the defensive toxins in
the plants’ leaves. In some cases, the plant toxins impart a nasty taste to the moth or butterfly which deters future would-be predators like birds. In fact, there are other butterflies or moths that even mimic the protected pollinator species to take advantage of that defense mechanism.
Furthermore, at least 25% of the world’s 20,000 bee species specialize on certain plant species because they have evolved to collect only those pollens to feed their young. As the field of ecology grows, scientists and naturalists are discovering these formerly unknown and exciting relationships between plants and pollinators.
bees emerge early in the spring as fruit trees are blooming and leafcutter bees emerge a little later when more, tender leaves become available. Pollinators like moths and butterflies have co-evolved with their larval host plants (where they lay their eggs) to tolerate the defensive toxins in
the plants’ leaves. In some cases, the plant toxins impart a nasty taste to the moth or butterfly which deters future would-be predators like birds. In fact, there are other butterflies or moths that even mimic the protected pollinator species to take advantage of that defense mechanism.
Furthermore, at least 25% of the world’s 20,000 bee species specialize on certain plant species because they have evolved to collect only those pollens to feed their young. As the field of ecology grows, scientists and naturalists are discovering these formerly unknown and exciting relationships between plants and pollinators.
Definition of “Native” For Buncombe County
Each ecological region is populated by a unique collection of native trees, shrubs, grasses and other annual, biennial and perennial plants. As exotic invasives like Japanese knotweed and kudzu demonstrate, just because a species will grow well here and pollinators collect its nectar or pollen, exotic invasive species are still very detrimental to longstanding local ecosystems when they displace the native (indigenous) plants on which native pollinators and other animals rely. Indeed, the reason exotic plants become invasive is their predators (insects and other animals, fungi, diseases, etc.) did not follow them to their new home to keep them in check.
Therefore, Asheville GreenWorks’ definition of a plant that is native here is a species that grew in the M221 Central Appalachian Broadleaf Forest--Coniferous Forest--Meadow Province (as designated in Bailey's Ecoregions) prior to European settlement. To check a species’ native status, we use the USDA Native Plants Database. While not perfect, this database is the best tool we have at the moment. The straight species is always ideal, however, when the straight species is not available, a cultivar is the next best thing. Labels indicate when a plant is a cultivar by following the genus and species name with a capitalized, italicized name in single quotation marks.
Therefore, Asheville GreenWorks’ definition of a plant that is native here is a species that grew in the M221 Central Appalachian Broadleaf Forest--Coniferous Forest--Meadow Province (as designated in Bailey's Ecoregions) prior to European settlement. To check a species’ native status, we use the USDA Native Plants Database. While not perfect, this database is the best tool we have at the moment. The straight species is always ideal, however, when the straight species is not available, a cultivar is the next best thing. Labels indicate when a plant is a cultivar by following the genus and species name with a capitalized, italicized name in single quotation marks.