This won't help you get pink flowers, but you can go to the island and do tours that don't require pocket space (like bug catching or fishing) and pick up all the white flowers you want. You can't get any hybrids or violets/lilies (if I remember correctly...) but you can pick up as many flowers as your pockets can hold and bring back as many as your box can hold! I filled my town up with flowers this way.
actually sold about 50 yesterday, so i only have 30 now, but i can do half tulips and half roses, with that. i usually do 0.5 tbt per normal flower, but alicat is correct that you can do the island method.
(i just buy mine bc it takes to long in my opinion lol )