Banana (Edible)

As soon as growth resumes, begin feeding and repeat roughly every two months through the growing season, using a fertilizer in a 3-1-6 N-P2O5-K2O ratio such as 6-2-12 with 2-3 percent magnesium. Give a young mat about half a pound to a pound per feeding and work up to 3-4 pounds per mat once the stalk is past 18 months, broadcast over the root zone rather than piled against the pseudostem. Add a micronutrient spray with manganese and zinc once or twice a year. A banana builds a whole pseudostem and a 25-40 pound bunch out of one season of growth, and its potash demand is what limits that bunch - the 3-1-6 ratio exists because potassium, not nitrogen, is the nutrient the fruit runs out of first.

Once the female flowers have set their hands of fruit and the stalk has stopped producing new hands, cut the purple male bud off the flower stalk just below the last hand. At the same time strip off dead leaves and any leaf rubbing against the bunch. The bell keeps growing and feeding on the plant long after it can add any fruit; removing it once the fruit is set puts that energy into the hands and speeds the bunch to maturity. Leaves sawing against the young fingers scar the skin.

Deliver about 1 to 1.5 inches of water per week, roughly 4 to 6 inches a month, concentrated over the root zone during dry weather. Do not put bananas on a lawn sprinkler timer - lawn schedules keep the soil continuously wet and rot the roots. On a high water table or heavy soil, plant on a 2-3 foot mound 4-10 feet across instead of trying to fix it with irrigation. That huge leaf canopy transpires hard and the shallow rhizome dries out fast, but bananas are also extremely susceptible to flooding and continuously wet soil, so the plant fails at both ends of the range - the target is steady moisture in soil that drains.

Keep three ages of pseudostem per mat and no more: one flowering or fruiting, one about half grown, and one small sucker or peeper. Cut every other sucker and peeper off at ground level, then gouge out as much of what remains as you can with a metal digging bar or a piece of rebar to kill the underground bud. The mat is one shared rhizome, so every extra pup is drawing on the same reserves that are supposed to fill the current bunch and grow the follower. Cutting a sucker off at the surface alone just makes it resprout - the bud has to be destroyed.

In prolonged warm, humid, rainy weather, watch for pale flecks that widen into brown streaks with yellow haloes and kill leaves from the oldest up. Strip and destroy the worst leaves first. If the mat is being defoliated, periodic applications of a copper fungicide and/or horticultural oil may be beneficial during prolonged wet periods. Fungicides are available, but may not be necessary for bananas in the home landscape. Yellow and black Sigatoka are Mycosphaerella leaf-spot fungi whose spores germinate on leaves held wet by warm rain. They do not kill the plant, but they strip the canopy early and a mat with no leaves cannot fill its bunch.

Harvest when the fingers are plump but before any of them start to turn yellow: the fruit is normal size for the variety, the ridged edges have smoothed and rounded off, and the sides have swelled. Aim to cut roughly 7 to 14 days before it would have ripened on the plant, then hang the bunch in a cool shady place to finish. Bananas ripened off the plant taste better than those left to yellow on the stalk, and a bunch left hanging splits, feeds birds and rots. The rounded edges are the reliable tell that the fingers have filled out.

After you take the bunch, cut that pseudostem off at the base and chop it into small pieces, leaving them on the ground around the mat as mulch. Keep the largest remaining follower as the next bearer. A pseudostem flowers and fruits exactly once and then dies - it will never bear again, and standing dead stems are where the banana weevil lays eggs and its grubs tunnel down into the rhizome. Chopping the stem up is both sanitation and a return of that potassium to the mat.

Ahead of the first hard cold, lay a good thick layer of mulch over the rhizomes. Do not cut down frost-blackened plants in the fall or winter - wait until growth restarts in spring and test each trunk then: one that is still strong and resists a moderately strong push is alive and will push new growth, while a dead one has gone soft and mushy with decay and will not stand up to the push. Take only the dead leaf blades off the survivors. Winter cold kills the pseudostems outright across most of the South, but a rhizome under mulch usually lives and resprouts. Since fruit takes three to six months to mature after flowering, every trunk that survives the winter standing is months of progress toward a bunch you would otherwise start over from zero.