Banana plants have high nitrogen and phosphorus needs and require regular fertilizing to keep up with the nutritional requirements of the plants. Apply organic mulch to the mat to protect and nourish the plant and use dry fertilizer regularly. Nutritional deficiencies affect the foliage and result in poor crops. When in doubt, a leaf analysis provides evidence of deficiencies and prescribes corrective nutrition.
Test your soil's pH and nutrient content, using a test kit. Nutritional needs will vary with soil pH. Whenever possible, adjust soil pH to between 5.5 and 6.5.
Fertilize newly planted bananas with 1/2 lb. of dry 8-10-8 fertilizer when the plants begin to emerge. Sprinkle the fertilizer over the mat and between the stalks.
Feed the bananas two months later, spreading the fertilizer about 1 foot away from each plant.
Feed a third time in another two months, this time spreading the fertilizer farther out, approximately 2 feet away from the plants.
Feed mature plants every two months, using 1 to 2 lbs. per mat for plants over six months old. Increase to 2 to 3 lbs. for mats between 12 and 18 months old and 3 to 4 lbs. for mats over 18 months old.
Apply a nutritional spray containing manganese and zinc once or twice a year.
Apply an iron supplement to the soil once a year in areas with iron deficiencies. Iron deficiencies will be indicated in the soil test.