Low Winter Temperatures in South Africa/Gethyllis

Mary Sue Ittner msittner@mcn.org
Mon, 19 Jul 2004 10:00:41 PDT
Dear All,

Gordon Summerfield in his post to me mentioned the lows that one of the 
species experienced in Sutherland which gave Jim McKenney hopes that he 
could grow Gethyllis.

Recently on our list there was a thread about South African bulbs and 
hardiness that made it clear that in cold winter climates some people could 
grow South African bulbs and some could not. David Fenwick plants his 
really deep which helps in the UK. Ellen Hornig has a protective cover of 
snow which keeps the soil temperatures moderated. Others no doubt count on 
mulch or tree cover. It appears that most of the bulbs that people are 
trying are summer growing bulbs from the Drakensberg. That would make sense 
since you would assume that since they would be dormant during the coldest 
time of the year they might be more tolerant.

For the longest time IBSA members have talked about the wonderful flora 
they see each year in another cold part of South Africa, but this one in 
the winter rainfall area. Sutherland which Gordon mentioned is in the area 
described in The Color Encyclopedia of Cape Bulbs as the Roggeveld Center. 
The higher elevations of this area (winter rainfall, but not a lot, up to 
250 mm or 10 inches in some areas) get cold and Sutherland is one of them. 
I keep hoping someone is going to do a field guide for this area 
(Sutherland-Middelpos) as there isn't one now. I read about these plants 
and want to see what they look like. It would be interesting to learn how 
many of them would survive in colder climates. They probably wouldn't make 
it in climates as cold as Jim Waddick and Jim Shields' however. Silverhill 
Seed occasionally collects seed there and that would seem to be one way to 
go since these species are not widely grown.

Most people grow Gethyllis in pots. Why couldn't they be brought inside to 
a cool room if the temperatures got really cold and then moved back outside 
when the cold spell passed. I've done that with plants here I cherished and 
didn't want to take a chance on. It surely doesn't stay at the extremely 
low temperatures all the time. The other factor I don't know about however 
is how they would do during summer temperatures. As Jim said you could 
shelter them from the rain and daytime hot temperatures are not a problem 
it appears. But I seem to recall Rachel saying that it cooled off at night 
in Sutherland even in summer. So perhaps the species most adapted to cold 
temperatures in winter, wouldn't like hot nighttime summer temperatures. So 
it might be the same thing as the Drakensberg plants, but this time it 
would be a matter of whether hot night time temperatures would be a problem 
during dormancy, not during growth. Until someone tries them however, we 
won't really know.

Mary Sue 

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