Hot iris/cool climates
It's good to throw in something and then sit back for a day or two to see
what everyone says!
I'll try to deal with what everyone says in turn:
Clarence Mahan - I think that genetics are the most important factor too. I
also agree with what you say about the causes behind winter losses in our
climate type - we have tried planting ours a little deeper this year in the
hope that frost heave will be less of a problem (they are all planted
mechanically so planting depth is easily controlled). I also think that the
sooner they are in the ground, the better, as a root system that has begun
developing before the winter offers better protection against heaving.
Fungicide treatment is also vital - we use Systhane (myclobutanil) after
planting and in late spring (before the flower stems really get going) and
have found it to be very effective in combatting leaf spot and rust - and it
seems to reduce soft rot by 50-60%. Use it with a wetting agent (washing
liquid will do).
Ellen Gallagher - you win! You are much colder than us! Our perception of
cold is relative - I read another message this morning where someone talks of
getting the heaters out when its 65F/18C! Most text books give our area on
the south coast of the UK as zone 8, sometimes zone 9. I think that the
people who write these books have never been here. Zone 9 might be the case
in the far south west (Cornwall and Scilly) but not here. The actual shore
area (within 1 mile of the shore) is about zone 8, whilst we are probably at
the coldest end on zone 8, almost zone 7 (we are about 4 miles inland). True,
we had a few seasons recently when the coldest nights were only 26 to 28F/-3
to -2C, but more often our coldest nights are down to 14 to 18F/-10 to -8C -
that's when we get problems with frost heave. As Clarence says, the other
problem is wet, and we are often faced with waterlogged soil conditions from
November to March - not good for irises. That's why we use raised beds to
combat this problem.
Rick Tasco - you are right. I should have qualified my statement about which
varieties do badly - it is generally the newer ones. Having said that, the
older varieties that we can get over here are all likely to be varieties that
grow well and "have stood the test of time"! It is interesting that you say
that pink has its background in plicata and variegata varieties (I do have
the World of Irises - but not the time to read it all!!) - it is those
varieties that often show this purple "stain" in the base of the fans. Anyone
who has grown some of the varieties that Clarence and others say do well
might like to report any further evidence of this correlation between purple
stained foliage and winter hardiness/cold climate performance.
Kathy Guest - thanks for tip re north east breeders. I haven't tried FRESNO
FROLIC but FRESNO FLASH does fairly well here (but not outstanding).
Mike Lowe - thanks for the tip - most older, "tried and tested" varieties do
well here, but I guess I'm too tempted by some of the newer shades and
Keep the suggestions coming for cold/cool/wet climate hot colour irises that
do well - classic or modern. Also more feedback on the purple stain/hardiness
Croftway Nursery, south coast, UK
Cool and dull again today. No rain though. Currently low 40s Farenheit. Tiny
frost last night.