La Puce wrote:

snips ...
Thanks Kay. Yes you're right, I've never thought of the species in the
Vervain and Pimpinella was what I meant. The 'wild look' you mention
was very much what I had in mind and I'm never that bothered about UK
native, only if there's a grant at the end for a project and I'll make
sure all is native!! However, even English Nature propose to plant
V.bonariiensis and many others non native. I suppose, like me, they
know that the wild life I get in my garden never distinguish between
vervain bonariensis or officinalis. Same with the thisles, marguerites
and scabiosas ;o)

There are good arguments in addition to financial advantage in favour of
using native plant species and trying to make sure they are true
natives:

1. The local wildlife does distinguish native from non-native. This will
be somewhat dependent on how far away from being true native the plant
species is but especially in the case of insects, the native insects do
know the difference - true native plants species will attract more
insects, both in terms of variety of species and overall numbers. And
where insects go, birds will follow. Planting true native plant species
provides greater food resources for local birds.

2. Genetic diversity - using non-native species risks diluting the local
genetic diversity. This may result in local wild plants losing
resistance to diseases and pest. There is also the argument that you
never know what you have really lost until it's too late.

And as the same large commercial suppliers are probably providing the
same seed species to many different markets, perhaps several countries,
because it costs less, the problem could be more widespread than it
appears.

3. Pests and diseases - non-native plant species may bring in pests and
diseases, or escape into the wild and become pests themselves.

I don't think that just because a government agency is doing something,
it means they are right. More likely, a major consideration of theirs is
also financial .....
--
Larry Stoter