I remembered floral doesn't 'do' video.

Here's a screenshot. Quite obviously a fern.

Are there any other ferns in the UK, vigorous enough to take over an area in full sun like this?

Bracken. No question. Very common. It's a native species growing in an appropriate habitat, so not a 'weed'.

Thanks! I didn't realize they could grow to that extent, in 'full' sun. (snicker snicker...) I did know it was native, but I tend to use the term 'invasive weed' for that kind of weed. Poison ivy would certainly seem a weed to you if you had to deal with it, living here!

Fair enough.

I use this definition

"a wild plant growing where it is not wanted and in competition with cultivated plants"

Presumably, that island was once grazed, and therefore grasses would have been desirable, not bracken.

I'm just amazed it can outcompete the grasses so well, but, of course, it's a different climate than I'm used to!

On the west coast of NZ, even wetter and milder, tree ferns grow in 'full sun'.

https://www.houzz.com/discussions/4307028/au-nz-travelogue-conclusion

If you Google Ynys Giffta you'll find lots of pictures showing the extent of the bracken on the island. Unless cut back, cultivated or grazed bracken will easily take over grassland. It grows best in full light, not shade. Near on mind that even. 'full sun' will not be constant sun, not very dry and not that hot in Wales.

I really hope to see Portmeirion one of these days. Maybe by then the fate of the island will be clear.

I wonder if it will be eventually be purchased by a land preservation trust of some kind. It would take someone with a lot of dough to redevelop it into a residential property! I'm reminded of that UK documentary about that guy on the south coast who sunk millions into his dream house, a proverbial 'tower overlooking the sea' and never finished it.

Just an aside but the PNW has its own species of bracken fern, Pteridium aquilinum, that looks and behaves virtually identical to the UK version. I often pass cleared or logged areas nearby that are totally covered by this plant.

Seems to be a widespread problem...There is also an Australian bracken fern species, Pteridium esculentum (Austral Bracken).

AUSTRAL BRACKEN

Pteridium aquilinum is the species we have here. That's what is growing on the Welsh island. I wouldn't call it 'derelict'. It's merely reverting to its natural state. Btw the range in the house is identical to the one in my kitchen.

"Btw the range in the house is identical to the one in my kitchen."

Of course it is!

In our climate (PNW notwithstanding, GG) the notion of an Aga, which is a constantly running oven in case some Americans don't know, is insane. But it makes sense 'across the pond'.

It's not exactly a constantly running oven. Ours has two sets of burners. One is for the oven and the other runs the central heating and hot water. The central heating and water are on timers and thermostats like any other system. They do not burn constantly, even in winter. The oven is run when required which is seldom as we also have a separate stove and hob.

Thanks for clarifying. When they came onto Americans' radars, maybe 15 years ago, there was talk back then that the traditional 'burn all the time' approach might be updated with changing attitudes towards fuel consumption. But I'd supposed many of them in the UK still operate that way.