Usually refers to growth rate, but may also refer to cold hardiness, and may refer to an ability to spread -- roots or top growth.

1. growth rate
2. ability to spread, especially vegetatively
...never heard of it used in reference to cold hardiness. I would tend to think that, when someone used it that way, maybe they were getting their words confused?

If a plant is not cold hardy, it will have trouble surviving, have stunted growth and be less vigourous. If it is cold hardy, it will survive where other plants do not, and outgrow other less suitable plants. The cold hardiness concept is an precept to growth rate, and vegetative regeneration.

And not many nurseries talk about cold hardiness. The zone will be mentioned, and that's about it -- otherwise the plants wouldn't sell as well.

And to that end, how fast a tree will grow, and how tall the tree will get, is also usually understated -- because many people get scared about planting a tree that will reach a mature height of 100 ft, so mature height is usually stated to be around 40 to 60 ft. The nurseries aren't lying, they just don't mention the tree doesn't stop there.

Still makes no sense to me. An extremely vigorous (growth rate) plant can be (and this is often the case) very un-hardy. Tropicals are frequently very vigorous.

when you get down to arguing about the vagaries of the english language.. you can get very confused ...

that is why it is simpler to just discuss two plants annual growth rate.. and understand.. that one is larger.. longer.. more vigorous than the other ...

dont get caught up in some web editors use of fancy words... make you miss the elephant in the room ... growth rate

see link for other fancy words akin to vigorous .. and scroll down toward aggressive syns ...

ken

http://www.thesaurus.com/browse/vigorous

well brandon the question was about trees, and I assumed (perhaps wrongly) that tibean lived in an area that is affected by frost/freezing temperatures, so cold hardiness would be a factor

Ken, a lot of what we talk about here on GardenWeb is terminology. Without proper terminology (or at least something close) we wouldn't be able to communicate and learning (at least online) would be impossible! If you don't understand the meaning of someone's words, then you don't know what they are talking about.

I've never heard the term vigorous in relation to hardiness, and so would be interested if I am missing something. I don't think I am, in this case, but ya never know what ya never know, if ya know what I mean.

When I see a tree described as vigorous, I take it to mean that it grows bigger, faster and stronger than other similar trees, given the appropriate growing conditions. I don't relate it to cold or heat tolerance, or drought or moisture tolerance, or any other environmental condition. A tree can be more cold tolerant than others in the same species, for example, but if it's a slow grower I wouldn't call it vigorous.

Brandon, what kind of tropical trees are vigorous?

Also, isn't a vigorous tree more likely to break and fall apart due to the fast growth rate?

And yes bstir, we do have freezes here in Arkansas Z7b but the winters can be pretty mild.

We had out first snow fall this winter just last week. Now the sun is out melting it all.

While maybe not technically considered a 'tree', Tetrapanax papyrifer is a semitropical evergreen shrub/small tree that is exceptionally vigorous. It grows rapidly and prolifically and even if damaged by winter cold (often behaves as a dieback perennial in colder climates), it will respond with rapid new growth as soon as the weather warms. In fact, this plant is so vigorous, it must be sited carefully so as not overwhelm nearby plantings.

As long as a very fast growing tree is allowed to grow normally, and is exposed to normal wind conditions, it should be strong enough to survive breakage. Many fast growing trees.shrubs are very limber

"Brandon, what kind of tropical trees are vigorous?"

There are so many. Since I am partial to Hawaii, I'll start with Acacia koa. When happy it grows extremely fast (at least compared to almost all trees in somewhere like here in Tennessee) and gets very large. Eucalyptus deglupta is another fast-growing, very large tree, and it has some awesome looking bark!

Vigorous is relative and I'd say that very many/most tropical trees are vigorous compared to most temperate tree.