My garden is 4 windows as I live in a 4-room apartment. Plants stand at different heights on the sills & hang at different levels.

My north-facing window has flowering plants:
Begonias - one I've had since at least 1978, it probably came from my parent's garden when they left Sydney, others include more recent cuttings & seedlings.
Geraniums - the pink one a clipping taken from a garden a few years back, the new red ones were seedlings boughta few months back.
Christmas cactus & Zygocactus - the same plant under different names: some flower winter ie. mid year, some flower spring/summer ie end of year.

My 3 east-facing windows have mainly green indoor plants as they face the next building & don't get such good light. The one flowering plant is also a refugee from my parent's garden - a hoya which flowers most years.

When I move in a few years I'll be in a ground-floor apartment & have a very small raised garden to accommodate my sore knees & back. It will include a lemon tree & a franjipani tree, hopefully tomatoes & a few vegs, & some flowers & maybe some potplants. I'll be living with some inner-city farmers & gardeners who will have the type of gardens discussed above. I'll still have plants in every window! And hopefully one will be north facing.

It will be great to have proper yards after living here since 1980 in a block with a very tiny courtyard containing only green leafy plants.

sandra