I'll be interested in the responses you get too. I have ferns in my GH that are showing all kinds of new growth, where they were outside, they held their own and looked nice, but there was no sign of ongoing growth.

It depends on the plants, the temp, and the light levels. I feed my palm trees 4 times a year, each season. I feed my orchids in the winter. Thats all I grow, so it works for me.

My GH is also, if not filled, then well graced with hanging pots of annuals, especially my favorites; ivy geranimums, and they get a very low dose of fertilizer every time they are watered, just as they do when hanging under the eaves of the house in summer. In return, they are blooming like mad.

Yesterday, I decapitated some pots of highly scented petunias and expect masses of fragrant blooms by mid-January- just when most needed to lighten winter blues.

BTW: if you want to have real fun with annuals, keep them in in multiples, with one in house and the others in the GH. When the housebound one starts dropping blooms and getting droopy from the dryer heat in the house, send it out to the GH for some R & R and bring in one of it's doppelgangers. It won't beat wintering in the Tropics, but might help carry you through until the first crocus pops up.

I have a few ivy geraniums as well. I find it very interesting that plants called annuals are surviving so well in the GH. I put several planters in the GH just to take up space so I wouldnÂt have to heat the empty space. I thought they would die in time but they are still going gangbusters. ItÂll be interesting to see just how long they live. Thanks folks I will be giving everything a little miracle grow whenever I water from not on.
Bernie

I fertilize anything growing. If a plant looks like it's resting I bypass fertilizing it. I use both chemical and organic fertilizers.

Regarding fertilizing, I usually feed on the same schedule as during the growing season, but only do it half strength. And only for the plants that are still growing and haven't gone dormant. If a plant loses it's leaves and isn't trying to put any new ones on, I'll hold off on feeding until I see new leaves sprouting.

It is interesting what plants commonly called annuals are actually perennials, isn't it? For instance, bedding begonias, peppers and tomatoes. Those are really perennials, what's called tender perennials (are killed by a freeze). They're easy to grow from seed and/or cuttings, so we grow them as annuals usually, but if we were to pot them up and keep them in a greenhouse, they'd last for years.

I forgot to say I use fish emulsion and liquid seaweed to fertilize with. The plants LOVE IT.

My plants are watered with filtered water from my fish tanks. I change out over 400 gal. a week and couldn't bring myself to just flush it away, so every plant gets a very low dose of the good stuff with every watering.

You would have to see the effect at least 300 of those gallons every week in the growing season had on some young shrubs to believe it- Super grow- Woosh! From 5 gal. pots to 5 ft screens in 2 years. Shrubs on steriods. LOL!

BTW: Annuals as perennals. Unless they are true annuals or bi-annuals, most plants are perennials- somewhere.

I know for a fact that geraniums can live for years. I have some in an old, black plastic kettle planter that my late mother planted in the last spring of her life in her own home, nearly 12 years ago now, and as long as I keep them trimmed for new growth, they bloom, year after year. Mum loved that silly planter.

Thank you all for all the input. I have been lurking here for the last year and a half. Your names are all familiar to me. IÂve read every last post on how to build, insulate, keep the GH warm, etc. Now I need to pick your brains on how to use it! ItÂs hard to know what questions to ask so IÂll just asked them as they come up.
Orchiddude your flowers are spectacular, reminds me of the shade house my father had on Maui years ago.

rjinga, greenhouser2, knittlin and birdwidow have you posted photos of your greenhouses? I canÂt remember seeing them if you did. If you have would you please post a link so I can go back and take a peek. Or post new photos as many of the older photos are gone now.

Birdwidow I have a small pond (about fifty gal.) with two gold fish in it. Whenever I flush it out I save every drop and use it on my plants as well. Yes indeed they do love it. In Hawaii Mom had geraniums that were about 30 years old when she passed away. They seemed to always be in bloom. Grandpa had a hedge of poinsettias that was 20Â long and at least 12Â tall. This time of year the entire thing would be covered with beautiful red bracs. All either of them ever did was prune once a year. Now that I have a greenhouse I will see if I can get my poinsettia to live long enough to bloom again next year.

Knittlin Every year it breaks my heart to see my peppers and my tomatoes succumb to winter. If my GH continues to do well this winter I will try to over winter at least one of each next year. IÂve never used fish emulsion. IÂm told it really stinks. How long before the smell goes away? My GH is only a 6X8 so itÂs not like I could get very far away from the plants. I love to have my morning coffee in there but I donÂt think I would enjoy it much if it smelled like fish.

So far our temps here have only dropped into the low twenties at night and IÂve managed to keep the temp at 50* in the GH. IsnÂt bubble wrap the best invention ever?! This weekend our highs will be in the teens and lows close to or below zero. I guess IÂll soon see what happens in there.
Thanks Again,
Bernie