Mary Fisher writes
...

I like lupins - they're from my childhood - but when I tried to grow them
here they suffered enormous grey aphids.


I like them, but they're slug-fodder.

I'm now trying to grow one in the slug-free environment of the greenhouse.
Ridiculous.

How do you get your greenhouse slug-free?

I can get it pretty well slug free by keeping the door shut at night,
and checking under and around pots at intervals and escorting out any
slugs and snails I find.

It would be more effective to search at night when they're feeding but
I'm rarely that well organised.

It's not totally successful, so this year I've taken to putting a few
slug pellets under the pots with particularly vulnerable things in.
It's a big greenhouse, with an inner and outer section. Slugs rarely
make it through into the inner section, but as that's obviously also the
hotter section, most of the vulnerable plants are in the outer section
within 2-3 feet of the door.
--
Kay