On 16/03/2010 16:39, Jeff Layman wrote:
"Chris J Dixon" wrote in message
...
Jeff Layman wrote:

There are very few invasive bulbs, particularly on clay soil. But one I
would particularly avoid is common muscari (grape hyacinth). If you have
good, free draining soil it will take over and is not easy to get rid
of as
the bulbs produce dozens of smaller bulblets when you dig them up. It
also
self-seeds everywhere.

I'll second that.

At the other end of the scale, I was surprised to hear on GW that
the iris reticulata, which are currently looking very good, are
unlikely to show much next year. Were they being unduly
pessimistic?

Chris

A bit. In IME they tend to die away slowly. Small irises don't compare
with crocuses for reliability every year, unfortunately.

The real devil is Iris danfordiae. This has attractive yellow flowers
but it breaks up into much smaller bulblets after flowering. These never
seem to get to flowering size again. The usual advice is to plant them
deeply which prevents them breaking up. Didn't work when I tried it.



I've heard this about I. reticulata and I. danfordiae. I've read that
they both break up into small bulblets and so fail to flower. I've also
read the 'plant deeply' advice but not tried it. I lose most of my
small irises to slugs.

On the subject of invading bulbous plants, I would advise caution with
some of the small ranunculus.

--
Spider
from high ground in SE London
gardening on clay