Mehitabel, i grow my plants indoor year-round.
All the plants are placed in front of my south-facing windows.

During the winter time, if I know it's going to be cloudy all-day, I would supplement my plants using two 125-w compact fluorescent. I use cfl because it's convenient for me to set up.

The biggest factor I need to watch for is over-watering. Then, pests like spidermites/scales but they are controllable. I would spray my plants every 2-3 weeks with neem oil (when I'm not lazy.)

Since I don't have a humidifier, I don't turn on the heater until the indoor temperature is below 50. I know plants hate the dry air.

If yours are outside, make sure to spray them before bringing them indoor. Good luck! :)

My house has no windows good for plants so I have a greenhouse. I do have a pest problem in it but that is my fault for not being diligent in spraying. I need a light in my greenhouse but haven't purchased one yet but they do live over without one. I have gardenias, Meyer lemon, stephanotis, and a couple different jasmine.

Mehitabel, All my jasmine plants are 2-3-4-5ft tall when outdoors. When I bring them indoors, I remove all old leaves and cut the plants down to 1ft for j.sambac varieties and 3ft for j.molle. I cut the plants though they have buds that might bloom indoors because I am sure I will be carrying pests indoors without trimming them. After trimming, I spray wash with water to get rid of big bugs if any in the morning, then in the evening I spray the plant with neem oil solution mix with dish soap. I spray the stems, leaves top/bottom to make sure if any minute bugs/ eggs, they get smothered with oil/soap to get destroyed. Once the spary dries out, I bring the plant indoors into my morning room next to kitchen. They stay good until Jan and then I notice spider mites on some due to dry air indoors. To treat them I give them good wash for big plants under shower small ones in kitchen sink. If I find severe spider mites infestation then I use neem oil treatment if needed but generally I don't use pesticides indoors. I do feed the plants with dyna gro foliar pro very diluted with each watering maintaining indoors. I water them only when the pots feel light when lifted, overwatering is very bad for any of these tropicals when indoors. I have been maintaining these plants this way 4-5 years now and it seems to be working out for me. I already trimmed some of my jasmines and brought them indoors. Hope this info is helpful.

Thanks for all the replies.

Kemistry and Buyorsell, the tip about spraying several times thru the winter is a good one. The pests take over so easily when the light is dim. They are good hiders and hard to see til they've overrun everything.

Kem, the reminder not to overwater is very timely. They need so much water when it's hot outside, especially when it's windy. It's easy to keep the heavy hand with water.

Kandhi, I can't thank you enough for the detailed reply. I never thought of cutting them back and taking off the old leaves. It makes perfect sense. I can also see I expected too much -- expected them to thrive and no pests. I also worried that they took a while to green up in summer. So seeing your patience rewarded with such gorgeous big fat jasmines encourages me to expect less in winter.

The "problems in January" is something I've noticed, also with orchids. Now I know it's January and not me :) I'll just have to be more watchful and ready to spray when there's a problem.

The water when pot is light is a good tip and one I use. Thanks again. Your tips will definitely help my spirits this winter.

Funny, isn't it, how you always get more when you expect less?