Invasiveness check

[Curtainsforus]

Is there a simple way to discover whether a plant is invasive or not?

It's hard enough dealing with bindweed, ground elder and green alkanet without introducing problem plants, like the 3 cornered leek but even the jasmine planted in my garden went rouge.
Is there a resource or a rating that I can check before I buy plants, sometimes the RHS site mentions it but not always.

I think it's a case of doing research before planting tbh. There aren't that many rampantly invasive plants to worry about - the most worrisome are the weeds you mentioned. Plants you buy from nurseries aren't as likely to be invasive - the label would usually have a warning if they had rampant tendencies. Even then, the level of rampantness is affected by conditions. For example Japanese anemone is known to be a thuggish plant, but in my garden it's very well behaved, probably because the conditions I have are slightly hostile (am on free draining sandy soil in a dry part of the country). I wish it was more thuggish tbh.

I think you would have to be careful if you're cultivating wildflowers as some of those really do have thuggish tendencies (rosebay willow herb for eg) which may not be warned about on a seed mix. I agree with you btw, summer jasmine goes nuts! I slightly regret planting mine, but it doesn't mind a severe hack to keep it under control.

The one thing I think should have a massive health warning is bamboo, including the so-called non-invasive clumping varieties. Because if they are happy they will eventually run riot.

Other than bamboo, vines like Ivy are another one to avoid and get everywhere once established.

The Americans seem to have some local category rating for invasive species

I agree with you - I bought a nice looking climber on sale but then discovered it was one of these “mile a minute” type vines that would take over the garden. Normally I do a google before buying something new but this was so cheap I didn’t bother.

Normally, my amber flag is anything described as “vigorous” because that often seems to mean “will grow in any conditions whether you want it to or not and resist all attempts at eradication” and would always then do more research.

I think you would have to be careful if you're cultivating wildflowers as some of those really do have thuggish tendencies (rosebay willow herb for eg) which may not be warned about on a seed mix. To be fair, I’ve yet to come across a seed mix which contains rosebay willowherb. Although there is a white flowered version sold for gardens.

most invasives are not UK natives and therefore short of native predators. Rosebay willowherb is non-native

Normally, my amber flag is anything described as “vigorous” That, and “self seeds freely”

Small ornamental grasses can be an absolute pain in the neck. They look lovely - little greeny-blue tufty things. Nope. Give them conditions to their liking and they are off like a bastard, and take over your entire rockery. Bitter experience talking!

Grape hyacinths can take over if you let them.

My garden is being taken over by day lily (hemerocallis) and primroses. I don't mind the primroses and the day lilies are OK in moderation... 🙁But I find it difficult to keep grape hyacinths and buddleia alive. The soil is heavy clay and very wet in winter.
So the invasiveness depends to some extent on your soil type.
Nb. If you live in a mild area with little frost don't let German Ivy loose in your garden! I brought some home from the Channel Islands, so far winter has kept it in check, thank goodness.

https://www.weedbusters.org.nz/what-are-weeds/weed-list/german-ivy/

One of my neighbours has grape hyacinths, as do all the kerbs and footpaths along the road outside their house. It's very pretty but going to cost the council a fortune to repair!

most invasives are not UK natives and therefore short of native predators. Rosebay willowherb is non-native

May you never be blessed with Horsetail.

We have it on our allotments, which were created during WW2. 80 years later of continuous attempts to get rid of it have failed.

Absolutely agree! I have it in my garden. Impossible to kill!