Walk-in Cold Frame
Forum Archives
Location: Olympic Peninsula
Posted: Aug-16-2004 at 6:21am
My greenhouse will remain unheated as fall comes into winter, so I was wondering........anything stopping me from using it as an overgrown coldframe for some more lettuce plantings? I have started more seed...a few varieties....any help here?
trav
Location: Washington, Western
Posted: Aug-16-2004 at 8:50am
I overwinter lettuce under a hoophouse, so your greenhouse should work just fine. The only thing you'll have to watch is that there's adequate air circulation. The hoophouse is basically open-ended - just plastic sheeting "doors" draping down to help protect on those really cold nights - so circulation is good. Greenhouses are usually much more sealed up than that, so you could potentially run into problems with things like downy mildew etc.
Travis
growsherown
Location: Olympic Peninsula
Posted: Aug-20-2004 at 8:02pm
Well, as far as it being "sealed", Im not sure I'd call it that. There are alot of "holes" where air is exchanged. Also, it has a screened window in the door, and a fan. Do you think this will still work as a coldframe?
Secondly, I dont have any sort of shallow trays for the lettuce plantings....can they be potted, left outside till the weathwer changes, then brought into the greenhouse/coldframe to continue growing?
Winter gardening is a very new and exciting concept for me, and I do apologize if these ?'s seem silly or repetitive, but I just want to try to avoid as many mistakes as possible. I can be very gung-ho at times, and it has been an expensive lesson learned a few times too, and I was hoping to rely on some seasoned advice from the pros here at RSG.
Picking your brains, trav
and LOVED your article on winter gardening too! (Thank you, sparklemama, for printing it out for me!)
trav
Location: Washington, Western
Posted: Aug-20-2004 at 10:26pm I'd be curious to hear from Debbie TT and others who have grown more in actual greenhouses - under my hoophouse I'm planting in the soil rather than in containers. But I'd think as long as you don't let the containers dry out (something I'm terrible at, actually) there's no reason your plan shouldn't work.
One thing to remember is that root systems are more sensitive to cold than the plant tops are, so if you can set the pots on the ground in the greenhouse - or devise some way to give the roots a little protection if we get a severe cold snap - your lettuces are more likely to make it through the winter.
Travis
Lisa A
Location: Oregon, Greater Portland Metro
Posted: Aug-21-2004 at 9:44am
Several years ago, there was an article in The Oregonian with how-to instructions for a plastic-covered hoop house that was heated by some type of electric cables on the ground. It was laid under the pots and was just sufficient to keep the roots warm enough to survive. I'll check to see if I saved the article - pretty sure I did - and post additional info.
DebbieTT
Location: Washington, Kitsap Peninsula
Posted: Aug-21-2004 at 10:59am
If the plants are in pots, I would be worried about the roots freezing. The cable ideas are good or bury the pots into the soil to keep roots insulated. My greenhouse I keep above freezing so I do not worry about roots freezing.
Even running an electrical cord out to the greenhouse and plugging a radiator style heater set at minimum temperatures will keep things warm enough. Alternatively, you can run out and switch it on when temperatures are going to go below freezing. Since we have minimal days of below freezing weather, it would not cost too much to heat only on the days or nights it freezes.
Be sure the plug you are using is rated for outdoor use, with the GFD style plug. I would hate to see anyone electrocute him or herself.
I always keep a fan running during winter. I open the green house up on milder days to keep fresh air circulating. Air circulation is very important for healthy plants.
gary
Location: Washington, Puget Sound Corridor
Posted: Aug-21-2004 at 4:03pm
Sorry folks but this is the EDIBLE Forum not the Orchid one, I opt for even simpler solutions because I agree with Eliot Coleman's dictum, "Why pay high energy prices to grow warm season crops without enough heat/light, when you can just choose to grow crops that like cold 'dark' weather?"
Some years I may use TSC's 'Growtherm' to get through the wettest/coldest times on spinach and lettuce. As Trav and Steve have said 'wet' is our worst problem most years. For cold tolerant lettuce, think varieties like Artic King, Winter Density, Four Seasons, Cracovienus (sp.), etc. TSC and Johnny's give good catalog descriptions of what we should expect from their varieties.
Debbie is right about protecting the roots of potted plants. One out of 7 or more years, I cover the root of my fig tree pots. If I would put them in the ground, I do not think I'd ever have to.
Do remember that my sun deprived site is warmer than the Oly AP winter temps you see on TV because the trees that shut the Sun, also protect me from many light frosts and moderate the heavy ones.
Flower growers should follow the same advice above, unless you choose to heat and light your greenhouse, all growing "stuff" shuts down in our less than 10 hours of daylight from about Nov. 10th to Feb. 10th. It is not the warmth but the LIGHT! The flower folks know about 'leggy' seedlings in 70F South windows in January. Vegetable grower's will learn the same lesson.
Sorry about the sermon above but as an 'old guy', I was selling/installing solar heating systems almost a decade before Steve Solomon published his first edition telling us there is not enough light in the Maritime PNW to GROW plants until February.
Trav's 'open' hoop house will allow you to survive most years. I am barely young enough to not have been growing vegetables in January 1950 (3 blocks south of this site) when the average Max at Oly AP was 32F. But were I much older, even with 115 years of data, only Jan 1931 and 1890 at Corvallis State U. were colder (less than a degree)!
Gary
sparklemama
Location: Western Washington
Posted: Aug-23-2004 at 9:59am
wow gary thanks for all that info! I sure think grows has a great idea for her greenhouse or should i be calling it a coldframe house..lol. These ideas i am def going to have to remember as hubby says he is going to build mine this year but who knows with him. Might have to be 'renting space' from my sweet nieghbor!..lol.
so do you have to grow those lettuces that are specific for winter if you are using a cold frame/hoop house?
Oh yeah guys i was wondering if either of you have tried TSC's Violetto Artichoke seeds?In the spring book it said that they were hardy to zone 6 i beileve, but i was wondering if anyone had any luck with that here?
gary
Location: Washington, Puget Sound Corridor
Posted: Aug-23-2004 at 1:00pm
No on the lettuces. Those varieties are among the many cold tolerant ones just like their ones that handle summer heat without bolting so fast.
Most good catalogs, like TSC, Johnny's, West Coast, will give you the information you need. The best year I've had is posted in photos at BLO near their Gro-Therm. They need to planted farther apart protected more from moisture than cold which is why I use the GroTherm. With that frame in place, it is real easy to throw some Remay, sheet, old blanket, etc. on top should really cold (20F) weather threaten.
In the photo at BLO, I was just using 9 ga. wire hoops to support the cloche. Now courtesy of a friend, I have a rectangular pvc pipe base with irrigation plastic pipe stuck into tees for the hoops. I stick a few pieces of rebar inside the pipe base to hold the whole structure down.
This simple structure moves around the garden all year. Right now it is serving as the Insect Remay support (for leaf miners & rust fly) over the beets, carrots, and fall spinach.
Gary
growsherown
Location: Olympic Peninsula
Posted: Aug-23-2004 at 7:03pm
holy moly.........alot to take in here. I'll fill my dug out pit in the greenhouse with sand, then nest the pots in that overwinter, (or as long as they live.lol) Hopefully, that will help. Im not necessarily trying to get the lettuces to last all winter long, and Im definatley not going to heat it all winter either, (conserving energy and my pocketbook, of course), but I would be happy w/ lettuces thru the fall.
Tnx for all the great tips!
Gardening for the Homebrewer: Grow and Process Plants for Making Beer, Wine, Gruit, Cider, Perry, and More
By co-authors Debbie Teashon (Rainy Side Gardeners) and Wendy Tweton