ReRoot America: How to Water
Early Stages: Immediately after planting, you will have to water more than you typically would water.
Summer: During the summer and the warmer months of the year, make sure to water the banana plant at least once every 2-3 days. Access to a sprinkler system may or may not provide sufficient amounts of water when it is hot outside.
Winter: Depending on how cold your climate gets, you may only have to water once every week or less. Your goal is to avoid making the plant sit in water so that it won’t rot.
Although it is better to plant in sunlight, if you plant in the shade you may have to water less. You can test the soil by sticking your finger in the ground near the plant. If the soil is moist for about an inch into the earth, you can wait to water the plant. If the soil is dry, you need to water the plant and continue checking on the soil every 2-3 days. Make sure to aim your water toward the roots and avoid watering the leaves.
Make sure NOT to overwater and leave the plant in a pool of water. Overwatering can kill the plant and or cause rotting of the root. An easy sign of over-watering or under-watering can be found in the leaves. Not enough water will cause the leaves to wilt and turn crispy while too much water will cause the leaves to wilt and be soft and limp.
One of the most destructive banana plant diseases is the Yellow Sigatoka Leaf Spot. The disease begins with small, light yellow spots or streaks parallel to the side vein of the leaf. The disease can only infect young banana leaves. Ascospores are released after rain and are spread by wind and rain. The most important factors for disease development are moisture on young leaves, caused by dew, rain or overhead watering, together with high temperatures. Hot and humid weather encourages rapid disease development. There is an incubation period of at least a month between infection and the appearance of leaf spots. Later, as the disease progresses, the spots elongate and turn brown with light gray centers. The spots elongate more and the tissue around them turns yellow and dies. Adjacent spots coalesce to form large lesions. The pathogen survives in the infected banana leaves and spreads via the wind. The period between fungicide applications depends on the climate and the amount of yellow Sigatoka already present. In the wet season, apply a protectant fungicide every three to four weeks. Either mancozeb (Dithane) with mineral oil or chlorothalonil (Bravp) can be used. Only apply fungicides in amounts recommended on the label. Infected and dead leaves will produce fungal spores as long as they are left on the plant. Early removal of diseased leaves is essential. Avoid removing all diseased leaves during the hot dry season because of their beneficial shading effects.