Pumpkins are heavy feeders and nutrient requirements change, as your pumpkin grows. For the first few weeks, your pumpkin will require a fertilizer with more Phosphate, such as Fox Farm’s Fruit and Flower to help establish roots.
For the next 3 weeks or so, switch to a higher Nitrogen fertilizer such as Fox Farm Tomato and Vegetable Food to encourage your pumpkin to produce vine and leaf growth.
About week 6 or 7, switch back to 5-10-5,
until first fruit set, then stop feeding until you can see the pumpkin has started.
At this point switch to a fertilizer with high Potash to encourage fruit growth and that’s what you’ll feed your pumpkin until harvest. The value of fish and seaweed fertilizers is they are loaded with amino acids, enzymes and micro-nutrients, great for supplementing your regular fertilizers, especially during the Nitrogen phase. th, 2014.