I would love to hear more about the progress of the greenhouse. I
live in NJ, and have constructed a 'hobby' greenhouse, it's like 6'
wide by 8' tall in the center, wasn't too difficult to erect, it's
about three years old now....but so far, unless i pack my plants
with hay, like i did last year and even that wasn't great, it just
gets too cold to winter over anything.  i have no electric.  but
maybe that's the answer and could plug in some lightbulbs as well? 
any tips would be appreciated.  i'm anxious for the next installment
on the greenhouse story.  thanks!

Yes I certainly would like to be able to read about continuting
progress of your plants and your thoughts.

Hi Angela, Your greenhouse project sounds interesting too. What's
the construction material? The wood frame 'hobby' houses I saw had
lots of openings at joints and along the wooden frame. Is that the
case with yours?

I've overwintered tender perennials in years past in a different
plastic greenhouse with a double plastic cover tucked tightly to
keep out cold air. The plants certainly need extra protection to
keep from freezing. 

I supplied heat from about 8 inches of hot horse manure in the
bottom and two or three spotlights to turn on as needed. I've place
small pots, my bog garden bowl and the more tender perennials -
rosemary, society garlic, scented geraniums on top of the manure.
The others go where they fit heightwise. I pack them in tightly. 

During winter, there's condensation on the plastic so plants don't
freeze - unless I neglect to turn on the lights. The plants don't
seem to mind the 'night light.' And they don't require much watering
- till spring.

On warm winter days, I remove the plastic and root around to see how
things are going. Yes, I loose the occasional marginal plant... but
most survive. 

So hay alone keeps your plants sufficiently warm? 
Charlotte
 

Thank you, Maddy. It's always encouraging when a reader writes an
note of appreciation. It helps me know what you're interested in
reading about. What type gardening do you do?
Charlotte

Hi, Charlotte, and thanks for the reply and great tips!!

I have a polycarbonate(plastic of sorts) hobby enthusiast 6X8
greenhouse.  It had some leakages, my husband had to caulk.  and we
put it up over wood, like a deck...it has two overhead windows
(vents) that i can pop open, and one on the lower floor wall.
The hay did ok, although messy in the spring to clear out, and I
managed to winter over my three year old miniature rose and my two
year old herbs (big deal!), but that wasn't quite up to my
expectations.  Funny too, that things I put in the greenhouse to
winter over, and didn't do so well?  Well, I found that once the
spring broke, I had things growing in (for example) these window
boxes that I planted in the fall; here pops an avocado (pit) plant,
and caladiums that I had planted prior to wintering over, suddenly
popped up in the spring and grew throughout the summer.  Lettuce,
too.  go figure.  
I need to keep things warmer....I don't mind going in and watering,
it's usually so wonderfully warm throughout the winter during the
day, but once the night hits, it gets mighty chilly in there!!!  I
love my greenhouse, I just need to perfect my style.

thanks!!!  Angela

Hi, Angela. Your polycarbonate greenhouse is like a small cabin
compared to my plastic tent of a greenhouse! I'm imagining you
walking around, watering under the warm sun. 

My space is no such winter respite, though I'm trying to arrange
plants so I can at least step inside to water.

The supplier of my structure shipped another plastic cover; said
only one other person has reported a similar poor-fit problem. I
wasn't anymore successful putting that one on so it would zip
closed. Now one's on top of the other; one zipper on each open at
the doorway but in different spots. I'm wondering if the frame
pieces were cut too large?

As night temps are dipping into the high 20s in Philadelphia area,
I've draped two huge clear plastic covers over the structure. I'll
tuck those ends under and anchor them with bricks all 'round to keep
out as much cold air as possible. Tomorrow I'll add two or three
metal clamp lights for warmth. And search for hot manure!

In your case, I'm wondering if your windowboxes benefit from
residual heat from your house. Maybe that's why those tender plants
didn't freeze last winter? 

Sounds like you're doing quite well with what you have. Refining
techniques and learning new methods and discovering plant surprises
- part of what makes gardening such fun, don't you think?

Pleasure "chatting" with you, Angela.
Blossoms Up! Charlotte