While all vegetables require some of the three basic nutrients (nitrogen, phosphorus and potassium)
and trace amounts of other minerals (e.g., iron, calcium, magnesium, etc.), specific classes of vegetables
do better with increased amounts of certain nutrients.

Nitrogen (N):  Leafy green vegetables, such as lettuce, spinach, chard, cabbages, broccoli, cauliflower,
                         onions and kale do well with plenty of nitrogen (e.g., from compost).

Phosphorus (P): Fruiting vegetables respond well to phosphorus (e.g., tomatoes, peppers, eggplant, beans, melons and squash). 
                           Bone meal and rock phosphate are sources of phosphorus.

Potassium (K): Root crops benefit from potassium (e.g., carrots, beets, radish, parsnips, turnips, rutabagas, potatoes).
                          Wood ashes can supply potassium.

George Bushell