My prayer plant used to have frequent white blooms. It has not had a white bloom in about seven months. It is in a large pot as it is a large plant. Why is it not blooming?
Cultivated Marantas are not noted for their flowering regularity. Often, they do not flower at all and their flowers are not particularly notable or scented. For that reason, many hybrid varieties do not flower at all. Hybridizers focus on the leaf markings as the key characteristic at the expense of the insignificant flowers.
Sometimes Marantas will flower for many months and then go through a rest period during which they do not flower at all. If yours has gone 7 months without flowering, that does not mean it will not flower again. However, it is difficult to predict when it may flower again.
There are several factors that affect flowering. Repotting into a larger pot almost always prevents flowering for a year or more until the plant is moderately potbound once again. Although Marantas do not require a lot of direct sunlight, if the available indirect sunlight is not very bright, then that reduced light will discourage flowering. Proper watering that allows the soil to dry just short of the wilt point will often encourage more flowering.