If it is a question of integrity, while it is true that G-d has granted the world a tremendous gift in the beauty of
nature, we are not forbidden to use substitute flowers, whether of wood, synthetic materials, or fabric.
If you are referring to the laws of the Sabbatical year, it depends where you are. The Sabbatical laws apply only in the holy land of Israel, or to produce from there, and thus again there is no problem in having flowers in your home, whether natural or fake. (If flowers come from Israel during the Sabbatical year, consult with an orthodox Rabbi.)
When having natural flowers or plants, wherever one lives, one should be careful that they don’t have insects and if they do, they should be kept away from food, since insects could fall in to the food and that is not kosher.
If you live in Israel, the Sabbatical year is coming up, and if you wish to use real flowers, you must consult a competent orthodox Rabbi.
Wishing you all the best!
