Recently I've had many requests that my next book should be about building a greenhouse, but I've been throwing around an idea more like a diary book of the perils and joys of building and keeping a greenhouse, or life with a greenhouse. Surely, the market is small for this topic, but it has had me recently hunting for reference as I incubate the idea.
Katheryn S Taylor's book 'Winter Flowers in Greenhouse and Sun-Heated Pit (1941) was my first go-to book when I dreamed of constructing a pit house as a teenager. Last week I spent some time revisiting it and noticed the bibliography in the back of the book that lists about 28 historical books used as reference and 36 books she called 'Reference Books', most of which are now on my wish list. Outdated, of course, but the physics should be the same. Many are 20th C. books such as 'The Cool Greenhouse and Conservatory' Gould-Adams (1965), the 'Unheated Greenhouse' (1907) K.L. Davidson. And others.
There seems to be increasing interest with cool and unheated greenhouses lately (with COVID perhaps and the rise in popularity of flower farming, slow flowers and hoop houses being more efficient). I do think many home gardeners are misguided when buying pre-fab smaller greenhouses that inevitably end up being seasonal 'she sheds,; but I have had at least 15 emails this year on real, home glass greenhouses from folks who want to raise camellias, force bulbs or for garden seedlings. I doubt that it's a true trend, (UK style) but part of me wants to believe that this other house plant trend with younger people (plant dads and plant moms) might result in some percentage of folks who eventually might be more interested in plants for the long-term. It's a wish, anyway.
I will add that I found Jim Jones book useful.
Lastly, to add to the thread - I heat my 23 x 26' glass house with propane. My burner is a newer Propane Modine heater, one without a pilot light and with external air feed (not sure what it was technically called, but our older Modine would explode when igniting on colder evenings which was scary). I was told that ours was overkill for the size greenhouse we have, but it does the job. We replaced it 5 years ago and some of the burner pipes had to be replaced last year as they rusted which also caused explosions (when igniting). IT has a fan and external exhaust so I think that might have helped with any gas issues - I mean, we could grow tomatoes and orchids without any problems that I can see.
I keep my house at 40º F at night, probably 34 deg. F near the foundation. There is a 4 foot concrete foundation wall, and gravel/soil on the floor. I live about 20 miles from fellow member Roy Herald outside of Boston in Zone 5b or 6a depending on what map you look at. Firmly in the north Atlantic Snow Belt according to Wikipediae where we can get 36" of snow during one nor'easter.
I did build a sort-of alpine house about ten years ago. I used a kit greenhouse, a Juliana I think, with aluminum frame and twinwall walls. I bought those aluminum raised sand plunge beds from the UK where I kept ariculas, other alpine primula such as alonii and tried bulbs (narcissus) as well as saxifrages. I was ignorant about so many things, but maybe that allowed me to experiment more. In short, I learned from the few alpine houses in North America that I needed more ventilation, so in the winter I would keep the top vents open and the door always open. I discovered that the auricula did fine, as did the saxifrage but they tended to bloom too early as the house would heat up on warm February days. I later learned to remove the sides of the alpine house in March or April, but often that was too late.
Bulbs were a disaster as the elevated beds froze. Later I learned to improvise a keep bulbs on the floor of the larger greenhouse just above freezing, and relocate them to the sand plunge beds in March and that worked. In January and February, I only kept primula and saxifrages in there. I would only close the vents and door on snowy nights. If I built one again, I would build solid plunge beds that went completely to the ground, maybe heating cables? Better vents. I always had to use shade cloth in late spring, which was problematic with high alpines that needed strong light. Summer was always the toughest time, keeping root aphids off of alpine primula was a constant battle, and over heating was always an issue. I think some afternoon shade might have helped, but out humid summer weather made things challenging.
In the end, I just accepted that a true alpine house was more of a fantasy than a reality in my location. I'm still hashing out ideas, but think that ventilation is always key, as is controlling winter temperatures. A larger structure might have allowed me to keep the sand beds just above freezing which would have been ideal, as would allowing beds to freeze solid as primula growers do in Alaska. Here, soil would thaw too many times given sun angles and unpredictable winter weather. Keeping such a space within a range of acceptable temperatures is a real challenge.
I now grow a few SA bulbs in the bigger glass house (nerine, oxalis) along with far too many other plants that I shouldn’t be trying to grow in the same space (camellia, cacti, orchids, veg seedlings and anything else that excites me).
Matt Mattus
Worcester, MA USA
Zone 6a, or 5b
On 11/1/21, 3:08 PM, "pbs on behalf of Judy Glattstein via pbs" <pbs-bounces@lists.pacificbulbsociety.net on behalf of pbs@lists.pacificbulbsociety.net> wrote:
Jane, it is "Winter Flowers in the Greenhouse and Sun-heated Pit", as I
mentioned up thread.
>>> _______________________________________________
>>> pbs mailing list
>>> pbs@lists.pacificbulbsociety.net
>>> http://lists.pacificbulbsociety.net/cgi-bin/…
>>> Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>
>>>
>> _______________________________________________
>> pbs mailing list
>> pbs@lists.pacificbulbsociety.net
>> http://lists.pacificbulbsociety.net/cgi-bin/…
>> Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>
> _______________________________________________
> pbs mailing list
> pbs@lists.pacificbulbsociety.net
> http://lists.pacificbulbsociety.net/cgi-bin/…
> Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus/
_______________________________________________
pbs mailing list
pbs@lists.pacificbulbsociety.net
http://lists.pacificbulbsociety.net/cgi-bin/…
Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>
_______________________________________________
pbs mailing list
pbs@lists.pacificbulbsociety.net
http://lists.pacificbulbsociety.net/cgi-bin/…
Unsubscribe: <mailto:pbs-unsubscribe@lists.pacificbulbsociety.net>