On 2013-08-13 08:57:06 +0100, Chris J Dixon said:

Sacha wrote:

Globemaster did well for us here for several years, probably about 4 or
5. They were planted in considerable numbers and always caused a lot of
interest and admiration. After that period though, they started to
lose vigour and produced smaller, though still very lovely heads and
were re-planted in containers for this year.

It was suggested to me by a grower that Alliums retain their
vigour better if dead-headed. Whilst I can see the logic, it
seems a waste, since the long-lasting seed heads are part of the
attraction.

Chris

Yes, I would think that the bulb farmers do that , rather as some
people take flowers off Hostas to promote leaf size. But as you say,
doing that to garden grown Alliums seems to defeat the purpose! I
would think ours flowered at full size for at least 4 years, diminished
a bit in the 5th and were really small this year, compared to what they
should be. We had planted them in containers, so in fact, their flower
head size was in perfect proportion for that. But taken overall, I
think that's not a bad investment!
--

Sacha
www.hillhousenursery.com
South Devon
www.helpforheroes.org.uk