From "The Fruit Gardener" Vol 18, No. 3 1986
How to Grow a Banana Tree
Being seedless, edible bananas are propagated by removing a sucker from the base of an adult tree. The sucker, also called a "pup," should be about 3 feet high. This insures it has already developed some of its own roots independent of the parent tree.
To remove the pup, use a long-narrow trenching shovel (or equivalent) and force a straight, downward cut between the parent and pup. After separating the two, pull out the pup, being careful to avoid breaking off the pup’s roots. Loosening the surrounding soil first would help.
The removed pup should be defoliated by cuffing at least 50 percent off of each leaf. This young banana tree can then be planted if it is spring or summer; otherwise, place it in a large pot using a good potting soil and keep it protected from the cold until spring. The planting hole should be 11/2 to 2 feet deep by 2-3 feet wide, with half the soil from the hole mixed with a mulch or planter mix. Spacing should be 6-8 feet for dwarf trees, and 10-14 feet for tall varieties.
Water frequently to keep the soil damp, but not soggy. Banana trees are heavy feeders of nitrogen and potassium, and so should be fertilized often.
The growth is rapid and fruiting usually occurs in 12-20 months. Each tree (pseudostem) produces one bunch, which usually matures in three to six months. Then the tree should be cut down, as it will otherwise die. The next crop comes from the following suckers which begin to appear before the parent tree fruits.
An adult banana tree should have two or three following suckers of various heights for continued fruiting. Excess suckers may be ‘pruned" by cutting at ground level. Too many suckers allowed to grow, or dug-up for replanting, can adversely affect the parent tree’s fruit development.
Ideal banana-growing temperatures are between 70 and85 deg. F. Growth stops below 60 F. Temperatures below freezing can kill the banana’s leaves, pseudostem surface, and young suckers. However, if the frost is brief, the banana will come back when the weather warms.
Over 40 varieties of dessert bananas and plantains are now being grown in California.
So if you have not yet done so, join those of us who have "gone bananas" and grow your own.