9 square meters of wheat will produce enough grain for around 10-25 loaves of bread according to this sight. It also says that wheat grown through winter rather then spring is more nutritious, is good for the soil as it protects the area over winter and the wheat doesn’t have to compete with weeds as does spring wheat, but needs to be planted early enough to establish a good root system before winter dormancy sets in. Wheat needs rich soil to grow.
10 to 25 is a big difference. It either means that if I want one loaf a bread a week I need to sew 2 and 5 beds. Then I need to add a few extra beds for other items that require flour (cakes, biscuits, muffins, quiches etc).