Greenhouse w/in a greenhouse to help heat (1st Winter)

I'm trying to think of economical/natural ways I can keep my tropicals warm in the GH this winter without wiring it up to look like the inside of my CPU, and I was thinking -- I have four of those metro shelving units on wheels for my GH -- each is about 4' L x 1.5' W x 3.5' H, and consists of 3 shelves. I wonder if it would help the plants to retain their own heat if I were to put clear "blankets" (e.g., clear shower curtain) over each shelf unit and put the plants on the two lower shelves, using the top shelf to drape the curtain over. Then, the heat could stay immediately surrounding each group of plants, and they'd still get light. I could also cover them with a real blanket (I have NO shortage of those in the house) in the later afternoon to help retain the heat overnight. Or would that be too much "greenhouse effect"?

Another idea I had was to fill 6 to 8 dark rubbermaid rough tote bins with potting soil. If I put these around the GH on the bottom shelf of each set of shelves, I'd think they'd warm up during the day, then help keep heat in the GH overnight, much like the barrels/jugs filled with water. And since they're on the bottom, the heat would rise up to the plants on the upper shelves. But would I be able to use the potting soil in the spring if it was kept in that type of container?

My GH is on the deck, so I have 1"-thick rubber padding on the floor to help keep from losing heat through the floor as well.

This is my first winter with the GH, which I bought to help shelter the tropicals during the cold season. Any suggestions/tips for ways I can do this naturally would be most appreciated! If anyone has a link to other threads of similiar content, I'd be most appreciative.

You can create a heat sink by filling black painted barrels of water in your GH which heat up during the day's sun and the warmed water helps keep the GH warm at night. There's lots of stuff on the web about it. Here's one link.

http://www.ehow.com/how_5458716_heat-greenhouse.html

I just read something about putting "row covers" over your tender plants for an additional boost of warmth inside the greenhouse. I saw it on one of the books at Amazon that talks about greenhouses. I'm reading anything I can find on it. LOL

Ummm... "if it would help the plants to retain their own heat " .... I don't think plants create a whole lotta heat. You need some source there - solar or otherwise - to start off with. Pastime's suggestion is the only one I know of, along with bricks that get warmed by the sun. The problem is often the heat release can happen before you really need it, so using things with a slow release (water is one of those) is going to be more effective than potting soil.

I use the water method, but it doesn't work on very cloudy, rainy days, so make sure to have another heat source.

Pagan -- what I meant was to help retain heat around individual plants within the greenhouse (GH w/in a GH).

I found for sale and ordered on ebay today rolls of bubble wrap that are 48" wide by 65', so I ordered some of that to help insulate the GH. I like the wider option for it to make it a little easier to install/apply. Also picked up some adhesive silicone caulk yesterday to seal up a couple of the small gaps in the frame to prevent heat loss.

Score! Joanna in Alberta used that last year, if I remember correctlya, sounds like it worked well for her.

I'm excited about it but racking my head how to attach/suspend it in there.

One of the TX gardeners ~ Charlenesplants did a greenhouse inside her greenhouse. She monitored temps and remarked at the notable warmer temps in the inside GH. Not that we see such hard cold but the more tropical plants received more protection. On the colder nights you could use a light for heat in the inside space.

How tall does that need to be to attach/suspend?

Hey, thought my ears were ringing :)

Yes the bubble wrap works great. Also, if you are in for a cold night and it is dry & calm, a bedspread or comforter over the roof works awesome. It made a 14ºF difference, but that was with a heat source. I don't think an electric heater with a fan would be too much to run for your coldest nights. Typically 1500 watts has a 12.8 amp draw. Be sure to use a good extension cord 10 or 12 gauge, for outdoor use.

Here's the link to the bubble wrap thread
http://davesgarden.com/community/forums/t/959872/


This message was edited Oct 18, 2009 9:09 PM

Can any of you help me on how to get the administration to respond. If this goes through I will be surprised, it has been denying me for weeks and I have requested my password and no one replies. I need help. I've missed all of you.
Linda

Thanks Joanna! I ordered it yesterday on ebay and hope to have it here by Wednesday. Tonight and tomorrow I'll be caulking up the GH while the temps are in the warmer range for the week, so it should be good to go come next weekend.

At the roof line, there is a small lip on each side. My thought is that I might be able to get some shower curtain rings that are springy to keep them closed, then just open them enough to put on the sheets of bubble wrap and sort of clip on each side of the lip. As the frame is aluminum, it'll be hard to afix anything to it, and I worry that even the 100-mph tape will break down with humidity in a short period of time. I'll conduct further investigating tonight when I get home, and try to take some pics to post. Right now, that baby is slam-packed full, and I can only get into it by crawling on m y hands and knees, LOL.

Ha - Nice visual!

Ha - Nice visual!

Hey Linda - hope you can read this - I sent your note in to Admin, hopefully someone will get you fixed up!

Linda ~ passwords are sent to you personal email (not dmail) ~ have you checked? Been there... done that!

I use clamps. http://www.teamworkphoto.com/images/misc/ponyclamp.jpg I picked them up at a flea market but have seen them in dollar stores, auto parts, wmarts. All sizes are available.

Also found it is expensive but the clear duct tape made by 3M will hold up best... cold, wet or hot, in past experience it will survive far better than any other tapes I've tried. I believe it is cost effective as I don't have to keep replacing it not counting my time spent.

curvesarein, you are indeed logged in--the Greenhouse forum is available only to subscribers ;o)

Please check your dmail and email inboxes; you should find our replies to your helpdesk notes.

Showing she joined April 2,09 also showing she "is a subscriber" when I put the cursor over her name?

Yep ;o)

I looked at clamps like that at Lowes, but they were really "strong" and I was afraid they may bend the aluminum.

Here's my next project. Got the yard marked for buried utilities & such so I can dig a trench and run power to my greenhouse. I will still use propane as my primary heat source, but it will be nice to run a fan without an extension cord. Have the Little Buddy propane heater (4000 & 9000 BTU) and also have a True North Caframo electric heater/fan (1500 watts with about 3000 BTU on High) for back-up and air movement. I only have a couple of weeks before the ground freezes.

sounds like a good idea & hopefully a quick little project. JB you will bring your potted roses in, right?

Nope, just in the process of transplanting them into the veggie garden for the winter. I mulch peat moss about a foot high at the base of the rose. I have better winter survival that way than in a heated garage. Some are Hybrid Teas and others are floribundas. This has worked well for a number of years.

Here's a link of what I do with my roses for the winter
http://davesgarden.com/community/forums/t/1047726/

This message was edited Oct 20, 2009 5:35 PM

great info & so timely, thanks for linking me there! Rose lovers do all they can for their babies, I know i try to.

I frequent a cafe by my office, and it paid off this week -- they gave me these Illy coffee cans with screw tops! I can think of a bunch of ways to use them, but first and foremost, my thoughts were to fill them with water to help heat the greenhouse in the winter as others have suggested (passive heat source). But I don't know that I want to have to paint them black for it to work. Do those of you who use the water/passive heat in your GH have all of the containers painted black? I realize it might be more absorbing of heat but wasn't sure how critical it was for this purpose/application.

Failed to mention, the cans are about 12" tall by 9 " wide.

You might want to save those nice canisters for something else and just use cheap (and plentiful!) milk jugs. Warning, you do have to use a *lot* to make any diff. I didn't notice any substantial warmth in my gh, but I didn't paint them black, either.

I didn't paint my 5 gallon buckets black last year and had about a 10 degrees warmer at night with them. I had 125 gallons in my 8x8 GH. The water will warm up to about room temperature from the heat inside the greenhouse during the day even if they don't get good sun beating on them. This year I switched to two 55 gallon drums and just a few buckets, and moved them to where they do get some direct sun with hopes that it helps a bit more. I'm testing out a solar water heater outside the greenhouse with the hot water running into those barrels, if it works I'll post the info.