Depends on what kind of garden you want!
Also some invasives might be desirable as many ground covers fall into this class.
You need to determine what it is you want to create in your garden.

Hi EarthChick:

Luckily for us, all non-natives are NOT invasive. Phew! Imagine if they were. Invasive means that they spread (like kudzu or japanese privet) or propagate by seed (like chinese privet or burning bush or purple loosetrife) at a rapid rate, usually overtaking areas to the exclusion of native plants. That is, they out-compete them.

Good examples of non-native and non-invasive are many of the annual plants that we use for color. However, this does vary by region. What may not be invasive for you, can still be invasive in warmer climates. Lantana is a popular bedding plant and it is not hardy for many of us, but in coastal areas like Florida, it is a pest.

I do have a few non-natives in my garden: daphne for winter flowers, daffodils for spring color, and of course some annual plants. Some people like to be purists and some are ok with having non-natives as long as they don't spread. It's really something you have to decide for yourself.

Hope that helps.

Good explanation esh ga.

Of course one can have non-native plants! Although I strive to grow all natives, I still have daffodils, tulips and hostas in my yard that were planted by previous homeowners. Being the lazy person that I am; I certainly am not going to make the effort to dig them all out just because they are not native.

And congratulations on getting your self informed on invasives. As people become aware of what is invasive and agree to not grow them and help control them; that will make the huge strides on minimizing the impacts of invasives.

I usually use the the term "invasive exotic" to clarify what I mean regarding plants like kudzu.
Even so, there are natives which can be invasive too. It is one of the reasons some people advocate growing plants not only native to your state, but also your ecotype (local ecosystem).

For myself, I grow a mix of natives and exotics which I know aren't invasive. The problem with growing purely natives is that there are some seasons that just really aren't that colorful, and adding a touch of annuals or a showy exotic can help "fill in the spaces". Besides, like most gardeners, I'm botanically curious. I kinda want to have certain plants precisely because they are unusual and unfamiliar.

Please note that many 'natives' can be obnoxious invasives at times. Golden ragwort(Senecio aureus) and Virginia creeper (Parthenocissus quinquefolia)for example, are lovely natives which can utterly destroy a diverse ecosystem in record time.

And then there are natives like poison ivy which can make life unpleasant! Smilax (thorny green vines for the most part) are certainly obnoxious to me.

One has to distinguish between plants that are invasive in natural settings and plants that are invasive in gardens. Lots of natives are invasive in the garden sense of the word. They spread in the garden and may require that the gardener control them. On the other hand, I don't know of any situations where a native plant has been invasive in a natural ecosystem, with the exception of Common Reed Phragmites australis (and it may be that a non-native variety of Phragmites is responsible for the invasion of east coast marshes). On the other hand, some species that are invasive in natural settings don't create much problem in the garden. For example, if you plant one of the shrub honeysuckles (e.g. Lonicera mackii) in your garden you'll probably have few problems with it - it won't spread about the garden very much, At the same time, however, it may be spreading seedlings throughout the local woods, displacing native plants and eventually taking over the understory of the woods. So think twice what is meant when someone says a plant is invasive.

But your question is whether invasive and non-native mean the same thing, and whether it is OK to grow nonnative plants in your garden. Not all non-native plants are invasive, and almost everyone has at least a few non-natives in their garden. Almost all vegetables are non-native, as are most lawn grasses. I think it is fine to grow non-natives, but I try to avoid them as much as possible. If there is a native alternative then I select the native plant, and I try to avoid any non-native plant that shows a tendency to spread, especially if it spread to any wild areas. Lots of plants commonly recognized as invasive were at one time grown as garden plants, and I bet that there are garden plants we use now that will in the future turn out to be troublesome invasives. For example, butterfly bush (buddleia davidii) is invasive in some parts of PA, and I wouldn't be surprised to see it listed as an invasive plant in future years. In the mean time, however, lots of people, even people who are concerned about things like invasive plants, are growing butterfly bushes not realizing they may be a problem. I won't even point out that Norway Maple, Bradford Pear, Common Privet, Water Hyacinth, and even Purple Loosestrife are commonly sold in nurseries - all are extremely invasive over a wide geographical range. I think that plants that have been in cultivation in the US for a long time are probably less likely to be a problem than pants that are newly intruduced, but you can never be sure.

So, I think that non-native daffodils are fine, but I'd get rid of that Russian Sage...

ladyslppr,

In general I agree but I've got a few picky points...

RE: "I don't know of any situations where a native plant has been invasive in a natural ecosystem, with the exception of Common Reed Phragmites australis"

Wow, that's a mighty big exception! I have my own theories about the spread of this reed, but nonetheless it does show that even a native species can be invasive and destructive to natural habitats when placed in the wrong ecosystem. There are often local ecosystems that by the sake of being surrounded by forest or otherwise isolated that wouldn't have contact with all other native species. When we introduce an agressive native to one of these situations we definitely can displace the original species.

RE: "Almost all vegetables are non-native". Actually... a great many are native. Keep in mind, the technical definition of "native" means that it was here prior to colonization. Native Americans grew many of the vegetables that we grow today. In fact, tomatoes, all peppers, corn, potatoes, sunflowers, squash, and pumpkin are new-world vegetables/fruits and most (except perhaps potatoes) were grown in N.A. prior to colonization making them "native plants". There are even a few native plants that had cultivated forms and were eaten as vegetables that we've lost.

So... one could technically go-native in the vegetable garden and barely suffer at all. ; )

yarthkin, you might want to do a bit of research on your veggie garden origins. Some veggies squash, corn, pumpkin, peppers(southwest states) are native ...

But most garden foods are not native. And the native veggies that we do grow have been cultivated to maximize production, such that what we eat is different than its origins.

Tomato was introduced into the United States in 1710.

Potatos came from mountains in Peru and Bolivia.

Peas came from Asia.

Green beans from the tropics.

I don't recall mentioning beans or peas... I did imply that potatoes were probably not eaten by native peoples in any part of the U.S. (the most I said about it, was that they were from the "new world", which is true). I can't prove it, but I suspect since tomatoes were grown by the Aztecs that were probably grown in some southwestern states at one time or another, especially since Native Americans did trade over fairly large distances. I know here in Virginia, another tomato relative, the ground cherry, was grown instead.

Anyway... I was responding to the comment that "Almost all vegetables are non-native". One might say "most" or "many", but I think saying "almost all" certainly doesn't do credit to the rather substantial contribution that native foods make to our diet on a daily basis. (Besides, I just like the idea of corn technically being a "native plant".)

Back to the topic of the thread, my point was that both what is actually considered "native" or "invasive" is rather difficult to nail down. For myself, I feel it is best to choose plants that will fit best into the local ecology, and most of the time that means a native plant. One still need to be careful though.

I agree the statement "almost all vegetables are non-native" is about as misleading as the statement "one could technically go-native in the vegetable garden and barely suffer at all".

True enough, if one were to go "native" in the vegetable garden, then you'd certainly want to plant some alternative native crops to supplement the plants that aren't native. Once you include those, you could indeed grow all natives and barely miss the rest. Many, like groundnuts, even have cultivars now. (At some point, I'll probably start a separate thread to talk about this more.) I'm also assuming that most people today use their gardens as a supplement to their diet, not as their sole source of food. Would be harder (but not undoable) if you were substance farming.

So... I agree, my statement was perhaps a bit misleading, but still not necessarily untrue. If you still disagree, then start a thread and we'll discuss it more.

Well, there are aggressive natives, and aggressive non-natives. Ragweed is an aggressive native, so are some asters and goldenrods and common milkweed. Whorled Milkweed, listed as rare in my area, is kind of aggressive. Virginia Waterleaf and turtleheads can be a huge pain. Even though they're native, if you have a small-ish garden space, you have to keep right on top of their spread.

Then there are non-aggressive non-natives...like irises, peonies, snapdragons, nicotiana, marigolds, spilanthes, geraniums, celosia, annual phlox, begonias, and tons of other stuff. I've got no problem with these, and I grow some of them myself, for early spring and late fall colour. They are no problem in zone 5A. They may be problems in other areas, though, so you have to be careful.

English Ivy and Vinca are always bad news.

It's hard to thread the needle...but it can be done.