It means that the plants have just sprouted out of the soil and the flowers have just bloomed.
Bud, unopened flower; flower bone. First bloom, just blooming. The buds are beginning to bloom, which means that the flowers have just bloomed and are about to bloom. Synonyms: budding.
Bei bud has two meanings: flower bones and flowers that have not yet bloomed. Flower buds, flowers that are still in bud. Also refers to innocent children.