Steve Tolen via pbs
Mon, 02 May 2022 11:53:51 PDT
 Tony,  Thank you for chiming in.  Zeeland is about 1/2 drive from me.  I will definitely contact Walters.Steve

    On Monday, May 2, 2022, 12:24:28 PM EDT, Tony Avent via pbs <> wrote:  
 I probably should chime in about alstroemeria winter hardiness. Obviously, as has been discussed A. psittacina is undoubtedly the hardiest species. After growing Mark Bridgen's hardy hybrids, we began experimenting for larger flowered options with the line of hybrids from Holland's Konst Alstroemerias. These were bred for the cut flower market and never intended to be grown as garden perennials.  We were shocked to find these reliable here in Zone 7b. We shared plants with Walters Gardens in Zeeland, Michigan, who started their own hardiness trials in Zone 5b Western Michigan. An extraordinary number have proven reliable in unprotected open fields with no mulch and an unreliable snow cover most winters. Over the last decade, Walters has recorded four winters of low temps between -10 F and -14F.  I cannot speak to the genes which have imparted such shocking winter hardiness to alstroemerias of florist quality, but the genus is far more winter hardy than most people realize.

Tony Avent
Juniper Level Botanic Garden and Plant Delights Nursery
Ph 919.772.4794/fx 919.772.4752
9241 Sauls Road, Raleigh, North Carolina  27603  USA
USDA Zone 7b/Winter 0-5 F/Summer 95-105F
"Preserving, Studying, Propagating, and Sharing the World's Flora" 

Since 1988, Plant Delights Nursery is THE Source for unique, rare and native perennial plants.


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-----Original Message-----
From: pbs <> On Behalf Of Jane McGary via pbs
Sent: Saturday, April 30, 2022 3:00 PM
Cc: Jane McGary <>
Subject: Re: [pbs] Alstroemeria

I don't want to repeat my entire taped rant about hardiness "zones," so will only note that when I lived near Estacada, in the Cascade foothills, an area Marc Rosenblum probably knows, my home appeared to sit on the line between Zone 8 and Zone 1 on the USDA map. Most winters the low was around 15 F, but about every fourth winter, colder temperatures occurred, the lowest being minus 6 F in the historic cold snap of 1990-91, which killed even some native plants all along the Pacific coast. My doubts expressed in an earlier post are admittedly subjective, based on a lifetime (75 come this July) of observation from central California to interior Alaska and 9 plant-hunting visits to western and Andean South America, as well as 30+ years of optimistic, experimental gardening. Unlike Hortus III and the RHS, I'm not using statistical methods, but the book "How To Lie with Statistics" comes to mind.

I do want to correct myself: when I wrote A. pulchella, I meant A. 
psittacina, which Garak's post mentions. Also note his phrase "for single nights," which may mean that the soil did not freeze to the depth of the tubers or even the growing points. Like many other geophytes, alstros can delve deeply. I once dug down to see how A. umbellata (a snow-zone central Andean) grew, and it was underneath about 30 cm of loose, dry talus and another 15 cm of fine, slightly moist sand (in January, the dry southern midsummer). That leads to another topic, the influence of rocky habitat in providing moisture to plants in arid climates, where fog or dew condenses on the rocks and trickles down. 
Whatever the books tell you, that is not "baking."

Jane McGary, Portland, Oregon, USA

On 4/29/2022 11:24 PM, Marc Rosenblum via pbs wrote:
> Jane,
> I estimated that most Alstromerias have a hardiness threshold of about
> 0 F [-18 C].
> Garak's -11C falls well above that threshold. I based my estimate on 
> Sunset, L.H. Bailey's Hortus III, and the RHS garden Plant Index.
> On 4/29/2022 8:53 PM, Garak via pbs wrote:
>> I can confirm that Ligtu hybrids, psittacinas and modern 
>> horticultural hybrids can tolerate unprotected, snowless frost of 
>> -11°C for single nights. Unlike the Ligtus, modern hybrids will lose 
>> overground growth to late frosts, but usually return soon after. I 
>> agree that my mixed winter climate is far more difficult for them 
>> than true continental climate would be. The psittacina actually has 
>> more problems with my dry summers, it's a really thirsty plant.
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