LILIES - RHS Lily Group

growing in half shade, so I have now moved my only surviving bulb to the drier
acid bed in full sun, in the hope that it will do better there. With the dryland lily
species, I find that incorporating pine needles together with the ericaceous acid
soil improves the drainage a lot, and also acidifies the soil a bit further, which
some of these lilies like.
I have also tried Lilium columbianum, which, for five years, has only produced
one small leaf per season. This may be because the bulb I purchased was too
young, and simply needs a few years to reach full flowering size.
I think that overall, my climate might be too dry for some of these lilies to be
able to thrive. (The Lilium canadense grown in Geneva Botanical Gardens also
seem to suffer a bit from the very warm and dry summers. It is, after all, a plant
which, in the wild, grows by streams and bogs in North America, where summer
temperatures are rarely as warm as the Swiss ones. Our record in 2005 was 38°C
in August, a summer temperature which is not rare, especially in August, which
is considered the warmest month in Switzerland).
Hybrids
Concerning the hybrids, the asiatic hybrid lilies grow profusely, and spread like
wildfire in my borders. (Four years ago, I purchased a bulb of Lilium ‘Citronella’,
which was a little bit smaller than a golf ball. When I dug it up a few years later,
while I was improving the drainage of my border, it had become the size of a
clenched fist. Lilium ‘Orange Triumph’, an old asiatic hybrid similar to Lilium
bulbiferum, needs excellent drainage to do well, flowering in early June with
gleaming orange, slightly scented flowers, opening from hairy buds.
The North Hybrid lilies, although becoming rarer to find, do very well overall,
with hybrids such as ‘Eros’, ‘Bronwen North’, ‘Angela North’ as well as some
unidentified orange and cream North Hybrids flowering profusely in June and
July, often producing over 20 flowers per stem.
I also grow oriental hybrids such as ‘Stargazer’ (one of my favourite lilies) and
‘Casablanca’ as well as some recent OTs such as ‘Faros’, ‘Conca d’Or’ and ‘Yellow
Stargazer’. However, I find that many of the oriental hybrids start declining after
a few years, and can be very sensitive to rotting. In recent years, they have also
started flowering much earlier, in late June and July, instead of in August as they
used to do. An interesting anecdote about ‘Yellow Stargazer’ is that after having
flowered profusely in June, it all of a sudden started growing a new shoot at the
end of August. Hopefully this new stem will flower before the first frosts!
Concerning the trumpet hybrids, these grow very profusely, and
make huge bulbs in time. They have also broken the records amongst my lilies in
all categories, with one stem of ‘Royal Gold’ producing 25 flowers, and another
stem reaching 206 cm.
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