As I read how people use various fertilizers and supplements and are organic or whatever I have noticed over the years, the ones who really, really grow the very best dahlias are the ones who do less fertilizer but more often. Most all of these exotic fish fertilizers and things like alfalfa meal or chicken feather meal or the strongest most powerful forms of chemical fertilizer work very well in small doses done often. Why does time release fertilizer work so well as it has the the same ingredients as the most powerful fertilizers? It is because plants want a little bit of fertilizer all the time, not all you can eat buffets once per month. I will always remember the fertilizer seminar done at Federation meeting where the very best exhibitors in the entire USA explained how they fertilized. The person who has proven to be the top show exhibitor of all, explained how she used cheap farm fertilizer in small doses and observed her plants carefully so she did not over fertilize or under fertilize. IF I WERE RICH and could use any fertilizer on the dahlias, I would either fertigate(fertilizer injected into the water in small amounts) and/or use the expensive osmocote type time release pellets., I would buy expensive equipment to measure the nitrogen in the dahlia leaves and have my crew with their pHDs keep track of the results of the fertilizer program. And a note on fish fertilizers and seaweed and such: Yes, they do have useful micro ingredients that your garden may be lacking. However, as with everything too much of a good thing is a bad thing and relying on these products as your main fertilizer year after year is probably not a good thing,
