In article ,
Steve Harris wrote:
In article , (Nick
Maclaren) wrote:

The idea is also to harden them against blackfly infestation.

Boggle. Mine never get attacked until they are a foot or more high,

I think the idea is that over-wintered plants, being a bit further
advanced, suffer LESS. Here, blackfly arrive around the beginning of
June and get steadily worse.

Considering that taller plants are slightly more likely to get attacked,
it seems fairly implausible.


Regards,
Nick Maclaren.