The winter in the north is relatively cold. If the potted plants are maintained, they should be moved indoors for winter. At the end of autumn, we should cut off the bulbs, put them in a cool and airy place to dry, and then put them in a sand basin, without watering or insolation, just keep them dry.
In addition, another way is to put it in a flowerpot and let the bulbs sleep naturally. Pay attention not to water them. The indoor temperature should be below 23 ℃. If temperature and water are not controlled, plants will continue to consume nutrients, which will affect next year's flowering and growth.
If a large area of open land is planted, it cannot be put indoors for winter. When winter comes, the leaves on the ground will start to dry out and fail. At this time, cut off the withered branches and leaves, and cover the plants with film, straw mat or soil, so as to keep warm and moisturize. At this time, we should pay attention not to water, or the underground seed ball is easy to be frostbitten and damaged. Or you can dig out the seed balls and store them in the sand, which can also keep them warm. After winter, we should plant the ball in time.