Growing Galanthus

[JimF]

"The Narcissus fly not like shade" - rubbish. I've lost bulbs to them in full shade cold troughs.
"The Narcissus fly doesnt fly high" - rubbish. I've seen them fly over the house after I try to kill 'em and miss.

I can tell you they do love to sunbathe. In my garden they like to sit on Colchicum leaves, rocks on the rockery and the edge of raised beds.

Their favourite plant for nectar is hardy Geraniums. Such a good feeling to quickly fold the petals around the fly and squeeze - evil LOL

I can only quote my experiences, Mark (and I did qualify the shade remark, as new bugs and pests are arriving each year here as our climate "adjusts". I've not heard from any of us in the Seattle/Bellevue area that grow galanthus or narcissus in numbers to have had any attacks of NBF in shade - and the fly is all over the west side of the state. We have 100 of acres in cultivation north of here. Between NBF and basal rot, the industry's in trouble. At homes, huge plantings of narcissus in full sun are wiped out or made blind in one year, while those in shade 20 feet away are not bothered. I consul customers all the time about this at the nursery.

Don't know about the flying high comment. Wasn't mine that I can see.

I know on the forum there's reference to different species of NBF, which surprised me when I started reading the forum. I personally was only aware of one species here. Perhaps there are different species in different continents, countries?

You've intrigued me enough to research this. Is our NBF (looks like "new best friend") indigenous or introduced?

Goodness knows a friend of mine did her PhD on weevils and discovered at least 8 species new to the area and 2 new to science. We all gasped and sighed at Rock Garden meeting when she told us. Oh, well, we are in line for a mega earthquake in the next 50 to 100 years, so "they" tell us - and volcanoes. I might just make a quake in 50 years.

Jim

[JimF]

A question: I grow some snowdrops fairly well outside in the ground - mostly nivalis. They are frozen solid every year. I should imagine they got at least -10°C at the roots this year since we had no snow. No harm whatsoever. What would be the difference to a pot potted plant?      Göte.

Göte  - I would think -10c would be unusually low for soil temperature even without snowcover. . . .

I remember a hort researcher once telling me that the ground temps are surprisingly high if the ground is moist but the temp can drop severely if the ground is very dry. 1990/91 was such a winter here, no precipitation from January to March and damage was amazing on certain perennials south to Virginia as I recall.  Even peonies were damaged, crocosmias were wiped out.

I guess tha damage in UK alpine houses in the past two years confirms the fact that even hardy potted bulbs cannot withstand minor cold.  But why is still a mystery to me. Rapid dessication or whatever....

johnw

Gote:
I agree with John added. He made it clearer. Nature, thankfully, still holds some mysteries.
Jim

[Peppa]

I remember that Jim brought some gorgeous snowdrops to our chapter meeting last spring!

[Maggi Young]

Mark - Jim is more than 6 degrees of latitude south of you and I am 10+. Perhaps the NBF behaves differently as you go south.  

johnw

Quite so: a critter that cannot cope with shade would soon die out in these parts!

[gote]

Thank you both for several good answers.
If the ground is frozen to say 20 cm (Our building code assumes up to a meter) the temperature at that level is zero °C. If the temperature at soil surface is -17°C as we had a couple of weeks ago, I would assume the temperature at Galanthus root level to be around - 10°C. Frozen soil is hardly a good insulator and there must be a temperature gradient from the surface and downwards. (otherwise frost would be uable to penetrate - there would be no heat transport upwards.)
The degree of dormacy makes sense to me as does the stability of the temperature.
Cheers
Göte

[johnw]

Göte - This may seem like a stupid question coming from a Canadian who should know all there is to know about snow and ice. So from one two who ankle skate, at normal atmospheric pressure just how cold can ice get?   Let's say at a minimum air temperature of -25c.

johnw

[Sean Fox]

Göte - This may seem like a stupid question coming from a Canadian who should know all there is to know about snow and ice. So from one two who ankle skate, at normal atmospheric pressure just how cold can ice get?   Let's say at a minimum air temperature of -25c.

johnw

Going by what Göte said earlier John the ice at the surface would be -25c with a temperature profile steadily rising the deeper you go. By Götes calculation this would make the temerature at the roots of Galanthus to be around -18c which is pretty damn cold. I guess it would also depend on the length of time the air stays at that temperature as to the level of penetration, but I'm sure Göte will correct me if I'm wrong.

[johnw]

Sean - These extreme temps are rare here and usually only briefly at night. However it is not uncommon to go to -15c most winters and the very occassionally a -15c high.  So given Tsuga canadensis is root hardy to only -7c the process must be very slow indeed, they do prefer ravines that are moist and a bit shady and that would further slow the process.  But it does grow in much colder areas which might see better snow cover the winter long than here on the coast.

Must keep an eye out for -40c ice cubes in gin and tonic season.

johnw

[Sean Fox]

John I would also assume the process to be fairly slow. I'm pretty sure I read somewhere that ice can get as low as nearly absolute zero although I wouldn't recommend icecubes at that temperature for your G and T's 

[gote]

Ice can olmost reach zero Kelvin so this is not a limiting factor. Studie on buildings built directly on a slab of concrete in a Swedish climate shows that equilibrium is reached after some two years = 700 days. The distance from the slab down, sideways to the outside and up to the soil surface is some 15 meter. meaning that it takes 700/1500 days per cm to reach equilibrium. That is 2cm/day. I can have a couple of weeks when the temperature never is higher than -10°C. Thus equilibrium down to some 30 cm.
I have no explanation to why tsuga roots survive but I would question the data. Tsuga seedlings would never survive in a harsh climate if the cannot stand colder than -6°C in the winter. My own tsugas have survived since the thirties. Maybe they would be in trouble at -6°F ??
Göte (who still has the soil frozen)
PS
 I could calculate this but it would take me a day.   

[johnw]

Göte

Do you grow magnolias in your garden?

Here water pipes must go down 1.25 m (approx. 4 feet).  Geothermal slinky/coil pipes with refrigerant for house heating at a friend's were down approx. 2.5m (approx. 7 feet) as I recall and gave her a 17.2c house temperature. Her soil was quite heavy but the installer's stated temp of 17.2 seemed awfully high to me.  Her neighbors have their coils at the bottom of the lake and they had a reading of close to 15c, this too seemed high to me.

johnw

[gote]

Göte

Do you grow magnolias in your garden?

Here water pipes must go down 1.25 m (approx. 4 feet).  Geothermal slinky/coil pipes with refrigerant for house heating at a friend's were down approx. 2.5m (approx. 7 feet) as I recall and gave her a 17.2c house temperature. Her soil was quite heavy but the installer's stated temp of 17.2 seemed awfully high to me.  Her neighbors have their coils at the bottom of the lake and they had a reading of close to 15c, this too seemed high to me.

johnw

Magnolia kobus, stellata and sieboldii. We have about the same required depths.
17.2 and 15 both seem awfully high. I have 9 at approximately 4 m (a well) and that is rather constant over the year. A lake with ice on top has a bottom temperature of 4. There is no way a lake can freeze over if the temperature is 17 anywhere. The density depends upon the temperature in such a way that warmer water would go to the top and melt the ice.
Göte
 

[johnw]

Göte      - I just checked with my friend and indeed her neighbors do have a side run into the lake but only for cooling in summer; they were so happy with it they put in another system, their main supply for heating, in their yard aside the lake.

Your magnolias are the hardiest ones I see.   Here it seems denudata is one of the most temperamental and soon shows its presence even as an understock.   After many years, I presume when it gets a very large root system, some selections of it do start to behave.  M. liliiflora 'O'Neil' is okay but the other liliifloras can be damaged in very cold winters - and yet crossed with tender ones like sprengeri 'Diva' it gives hardy hybrids as does denudata.  Makes little sense.

johnw

 

[gote]

Summer temperatures are of course quite different animal. I have measured 27°C in July. That year was unusually warm and I measured it in a shallow bay.
Normally we have 18-22 in the warmest time of the year.
I will try to remember to put down temperature probes in the fall. Hopefully I will have some results next winter.
However,  We usually have unusual weather.
My ground thawing at last  Horray!
Göte

[johnw]

"We usually have unusual weather."

Göte

Not here, we only have abnormal winters.  

Inland lakes here can get get quite warm in summer. I have seen +27c sea water in protected bays.  This is only in the upper layer where one swims and this is when one might catch a glimpse of a sunfish.  The upper sea temperature can change dramatically from day to day depending on the wind direction. Usually August, Sept and sometimes October are best for ocean swimming.

It would seem that Jim's comment on the stability of outdoor soil temperature and its gradually decrease as opposed to pots seems like the most reasonable explanation.


johnw - circa +1c