Repotted mature geraniums initially gave us large flowers, now the buds and flowers are much smaller, why?

Question:

Answers:
They were probably dosed with a high phosphorus foliar fertilization at the greenhouses before they were shipped to be sold. This is a inexpensive way to make a greenhouses plants look nice for sale. Once they are established in their new location (and you are sure they are through the root shock of being planted) you can use a Bloom Booster fertilizer on them to see if they just need a little more P. Shultz makes a very good liquid bloom booster. (The numbers should be something like 10-50-10.)

Also make sure you dead-head all the spent blooms. If you don't, the plant puts its energy toward the seed production from those earlier flowers.