The NRCS (Natural Resources Conservation Service, a division of the USDA) gives pretty clear understandings of just what exactly qualifies as a native, invasive, and other plant category definitions. In fact, we're going to directly pull from their website here for that information, so we're all on the same page when it comes to "native" plants.
First off, here are the different categories of plants they recognize:
- Native Plant
- Invasive Plant
- Non-Native Plant
- Naturalized Plant
- Exotic Plant
- Translocated Plant
- Opportunistic Native Plant
- Weed
- Noxious Weed
Native Plants
"A plant that is a part of the balance of nature that has developed over hundreds or thousands of years in a particular region or ecosystem. Note: The word native should always be used with a geographic qualifier (that is, native to New England [for example]). Only plants found in this country before European settlement are considered to be native to the United States."
Basically put, plants that have been around here for a long time. This is over-simplified but if it was here before Europeans settled the United States, then it is native to this country.
Invasive Plants
"A plant that is both non-native and able to establish on many sites, grow quickly, and spread to the point of disrupting plant communities or ecosystems. Note: From the Presidential Executive Order 13112 (February 1999): 'An invasive species is defined as a species that is 1) non-native (or alien) to the ecosystem under consideration and 2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health.' In contrast to item 2) of the Executive Order, which includes plants invasive in agricultural settings, the Connecticut Invasive Plant Working Group lists non-native plants as invasive only if they invade minimally managed (natural) areas."
Simply stated, an invasive plant is a plant that can grow quickly and spread out to cause harm.
Non-Native Plant
"A plant introduced with human help (intentionally or accidentally) to a new place or new type of habitat where it was not previously found. Note: Not all non-native plants are invasive. In fact, when many non-native plants are introduced to new places, they cannot reproduce or spread readily without continued human help (for example, many ornamental plants)."
This one is pretty easy to understand in concept but practical applications can be a bit more confusing. An example of a non-native plant in this case would be tomatoes. In fact, many non-native plants in this category may find their way on to your plate. However, when researching "non-native plants" online, you'll find many are in fact invasive plants. This can be cause of some confusion between "invasive plants" and "non-native plants."
Naturalized Plant
"A non-native plant that does not need human help to reproduce and maintain itself over time in an area where it is not native. Notes: Even though their offspring reproduce and spread naturally (without human help), naturalized plants do not, over time, become native members of the local plant community. Many naturalized plants are found primarily near human-dominated areas; and, sometimes, naturalized is used (confusingly) to refer specifically to naturally reproducing, non-native plants that do not invade areas dominated by native vegetation. However, since invasive plants also reproduce and spread without human help, they also are naturalized invasives are a small, but troublesome, sub-category of naturalized plants."
Excuse the pun here, but this is where we start to go off into the weeds. HA. So basically stated, these are plants that need no human help to reproduce and maintain themselves over time in an area where they are not native. But as with anything in nature, there are nuances to this category that can be confusing.
Exotic Plant
"A plant not native to the continent on which it is now found. (Plants from Europe are exotic in North America; plants from North America are exotic in Japan.)"
Translocated Plant
"A plant not native to the portion of the continent where it is now found. (California Poppies in New England are an example of a translocated species.)"
Opportunistic Native Plant
"A native plant that is able to take advantage of disturbance to the soil or existing vegetation to spread quickly and out-compete the other plants on the disturbed site."
Weed
"Common Usage - A weed is a plant (native or non-native) that is not valued in the place where it is growing (USDA Animal and Plant Health Inspection Service (APHIS)). Definition - Any plant that poses a major threat to agriculture and/or natural ecosystems within the United States."
Noxious Weed
"Common Usage - A plant that is particularly troublesome. Legal Context (Federal Plant Protection Act) - Any plant or plant product that can directly or indirectly injure or cause damage to crops (including nursery stock or plant products), livestock, poultry or other interests of agriculture, irrigation, navigation, the natural resources of the United States, the public health, or the environment. Note: USDA APHIS maintains a list of federally-recognized noxious weeds. It is illegal to import Federally listed noxious weeds or transport them across state lines. Some states or counties maintain lists and have passed laws regarding responsibilities for their control (not applicable in Connecticut). Connecticut laws ban the sale or transport of noxious weed seeds."
What's important to note here is that noxious weeds cause damage while weeds in general are more/less unwanted plants growing in an area.
ALL our seed mixes are tested by a laboratory to determine what, if any, noxious weed seeds are present. Any seed lot or mix that does not meet the NRCS/USDA guidelines for planting in the United States is destroyed.