Do I need insulation?

I'm not planning to start sowing seeds until the back end of Feb this year & as there is nothing overwintering in it I haven't bothered putting up the bubble plastic yet, so my question is do I really need to? the seedlings would not be out of the propagator until early march so it does not really seem worth it :confused:

 

I think you've answered your own question. I have a new greenhouse which I only bought in September. I haven't put up any bubble wrap because I think it looks ugly but I do have a small heater which kicks in if the temperature drops. I only have a few half hardy plants overwintering, nothing precious, so they will have to take their chance. As everything does in my garden. If it's not happy here or needs bags of attention then I can live without it. Or at least until I have more time to lavish on my garden - if only!

 

What time of year would bubble plastic normally be taken down?

 

I have only used bubble wrap this year for the first time. However I am aware that what you may gain in temperature you may lose in lack of ventilation and botrytis.

Consequently yesterday I removed all the rotting vegitation from the slightly tender plants that I am overwintering - such as Lobelia Cardinalis. The new rosettes underneath look very healthy. I am trying to leave the door open (when I can remember) to remove some of the condensation on the bubble wrap.

Having said that the minimum temperature inside has been 10 to 12C higher than outside.

Edit 24 Jan. My mechanical hi/lo thermometer was indicating 10C higher than outside. But I have become suspicious so I have just checked it with a mercury hi/lo thermometer, and its much less - only a degree or two.

[ 24. January 2006, 09:12 PM: Message edited by: PeterS ]

 

I have never used it, always seems a hell of a job to get all the plants out, then try to pass it down behind the staging.
I think you must gain a bit, economy wise, but there is the condensation problem Peter refers to, and then you've got to remove it all.
It doesn't really fit in, in the way I use my greenhouse.

 

I'm using it for the first time this year and the difference is amazing.

I have a fan heater which is very rarely on, nad the temperature is a steady 14C. Probably too warm really, but I'm still learning.

I've been giving the plants a daily spray with warmed rain water to create a bit of humidity to help keep down the red spider mites and have no condensation at all.

It serves a second purpose in that the roof leaks when it rains and the bubble wrap stops the water getting to the electrics and in my wellies.

 

Is the toughened glass any better at keeping the heat in?

 

I dont think so :rolleyes:

 

If your starting seeds off at the end of february in propogators, then unless they are tender, they should be fine in an uninsulated greenhouse. If your planning on tender plants, then leave the seed planting til late April.

 

The reason I'm doing it is that I have a load of gardeners coming here in July and I want the daturas etc to be in bloom.

 

I put up my little greenhouse last autumn purely as extra space for overwintering frost tender exotics eg lemons, strelitzeas, palms etc. There isn't any staging so the bubble was easy to fix. Whether it will ever be taken down is anybodies guess.
To combat condensation I fitted a small extractor fan on a timer. An hour in the morning and another in the afternoon seems to do the trick, without drying out the pots too much.
The plants won't emerge until May at the earliest, so the greenhouse will not be a lot of use for seedlings or tomatoes during the summer.
Two deck chairs and a drinks table will probably be it.
Nik

 

Greenhouse insulation is an interesting subject.

When i did my foundation i installed polystyrene sheeting (2ft deep x 2" thick) vertically around the perimeter to insulate the greenhouse floor from the surrounding garden soil. It didn`t cost much to do and it should help reduce costs.

As greenhouses are probably the worst possible structure for retaining heat i think insulation is very important if you plan to use heating.

 

I have used bubble wrap on two or three occasions before and you do end up with alot of condensation on the inside of the greenhouse.I havent used it this year, i have got a fan heater which has a thermostat set to 3 or 4 degrees just to take the chill off.The bubble wrap is messy to put up and take down, it also reduces the light a little in the greenhouse.I have been overwintering a few tender plants in a coldframe in the greenhouse fitted with a heatmat.