From Longman Dictionary of Contemporary Englishin flowerin flowerDLGHBPa plant or tree that is in flower has flowers on it SYN in bloom It was May, and the apple trees were all in flower. Roses start to come into flower in June. → flower
Examples from the Corpus
come into flower• In the garden of the little farm, fruit trees are coming into flower, and others are beginning to leaf.• When planted through beds of hybrid tea or floribunda rosea they add interest before the roses come into flower. 