Mandevilla with small leaves and no flowers

I need help with my Mandevilla plant. I live in Zone 3 in Minnesota and so my plant is a house plant. It is in a fairly large pot, I water it carefully and it sits in a South facing window. My problem is the leaves stay small and several drop off. I do not cut back the vines. It also has never flowered in the two years I've had it. Any help would be appreciated.

Thanks for posting this Sue. I've been wanting to post one like this. I have a Mandevilla Tango Twirl that has not bloomed since I got it. There has to be a trick to it. SOmeone will surely come along soon to give advice!

You might have better luck getting an answer to your question if you posted it here http://davesgarden.com/community/forums/f/b_gardentalk/all/

This forum is just for help with the PlantFiles database. More people hang out on the other forum. Hopefully someone will have answer to your question.

Have you tried putting it outside for the summer? They will take full sun in the summer where you are (I would think...) but leave it indoors for your winter. Maybe put it out in spring when the cold is over.

Hi Sue, sorry I am late picking up your thread, I have a huge plant now, but it took a couple of years for it to flower, they do go really leggy and if you dont give it a climbing frame to get up onto, you will need to prune it, it has been covered this year with bright red trumpet flowers, I keep mine in good light but not at a glass window as the magnification from the glass scorches the leaves, the new leaf are smaller than the adult ones and are a lovely shinny green, watch out if you prune it as it drips a white milky liquid that becomes a bit sticky if on your hands, so wash your hands after that, I feed mine from spring to end of summer with a good liquid plant feed, I use a seaweed one, but I am sure a tomato feed would do the same, I use the seaweed on my tomatoes anyway and buy a large container of the stuff. I stop feeding when the temp gets cooler outdoors even though my plant is growing in the conservatory, because like you, I had no flowers on mine, I started to nip off the growing tips of each stem, and it really got nice a thick growth going with lots of new stems, so maybe that helped it get into action, so try that early next spring once you see it start to form new growth, it may just help, but I think feeding in the growing season and less direct sunlight will also help as the foliage is probably suffering from too much hot sun through the window, the flower buds are like little rolled up toffee papers when first seen and then open into the lovely trumpets, I deadhead it all summer once the flowers get a bit limp, they dont last long, but remove any soon as you see then soften and limp. Hope this will help you a bit, good luck. WeeNel.