Greenhouse questions

[tam91]

Excitement! I put up my greenhouse today, set up most of the shelves, and set up the heater - I'll check tomorrow morning to make sure everything worked ok and held the temperature before I put any plants in it. I have this one:

http://www.farmandfleet.com/products...reenhouse.html

I would highly recommend it - really sturdy, and I can put it together myself in not very much time at all. I used it last year in the spring, and it's good as new this year.

Question - I can't remember - what is a good minimum temperature? I think I may have had it at 50 degrees, or was that 45.....? I plan to put some tomatoes and broccoli out there. Also perhaps the Swiss Chard. Peppers and basil and most floweers will wait until it's reliably a bit warmer.

So - what would you suggest as a minimum overnight temperature for tomatoes, and also for peppers etc?

The other question - I need an idea. Last year, when I put the Swiss Chard out there, some chipmunk or something kept getting in there and eating it. Oddly, nothing eats it in the garden, but I just could not keep it in the greenhouse. There is no way to really keep a little critter out. Anything anyone can think of I could put around a flat or two to keep it safe from critters?

Edited to add: I should have been clear - I'm not trying to grow these to fruit in the greenhouse, they're the tiny seedlings I'm trying to raise until I plant them out.