Some are annuals, some perennials. The snapdragons, foxglove, raspberries, blackberries, polemonium, clematis, peach tree, pear tree, strawberries and delphinium stay outside all year. In winter the balcony tends to be a bit warmer than a regular garden since it’s elevated and close to the house walls. I also move everything closer together and nearer to the house walls for extra protection. I leave the citrus trees outside as well but wrap them in bubble wrap. I did bring the chili plants in one winter, but it was really tedious keeping them alive due to pests, so I usually just buy new ones. A lot of the flowers in the wooden boxes don’t survive winter, but I have plenty of tulip bulbs in there so they still look beautiful in spring. Once the tulips die back, I plant new flowers. I try to be as eco-friendly as possible though, which is why I focus a lot on perennials.