Hardy bananas, gingers and canna's
Coming out of winter
I get quite a number of calls every spring about when the banana will come back from the winter damaged trunk. If the trunk was severely frozen the banana does not come back from last years pseudostem. Bananas are a corm. The new growth comes back from some where else on the corm, unless of course the pseudostem did not get damaged. I have had many winters where the older bananas with their very fat trunks have only frozen down to maybe half the original height. Then they will come back! The image at right is from a little test I did last year to attempt to find the smallest potted size banana planted in June with no winter protection and would come back. This was a 1 gallon container, fed very heavily and cared for quite well. It got to about 5 feet tall before winter. The arrow points to the old main trunk. One can see by how close the new growth is the corm is not all that large yet. If you where able to notice on the home page that cluster of new growth is about 18 or more inches across.
The image here is from a quite old banana which comes up later than the others because now it grows in almost total shade because the bamboos and palms around it have gotten so large. Notice on thing here I do not remove the melted down plant. You can see all the old damaged leaves just pulled out of the way to show the new growth. I leave it there until we are completely frost free. The old pseudostem's here are 6-7 inches in diameter. Another point is notice how wide the older stems are spaced. This banana takes up about 5 feet of space, well actually that was last year.
Planting bananas
Bananas require heavy watering and feeding during the growing season to be at their best. Full sun is optimum but they will grow in partial shade; this is mostly true for Musa basjoo. For Musa sikkimensis and Musaella lasiocarpa, full sun seems to be best. Beware of planting in windy sites as the thin leaves are easily torn. Of course the island look isn't all bad! It is best to not allow the soil to dry out in the growing season. Good drainage is essential and, although it seems impossible to over-water, bananas will not survive in standing water. We use a soil mix that is about 30 percent sand, 30 percent native soils (including clays), and the remainder consisting of compost.
Feeding bananas
Being gross feeders, bananas appreciate plenty of fertilizer. We use 21-7-14 in the spring after the first leaves start to grow. Then, on alternating months, we rotate between 21-0-0 and 21-7-14 during the growing season. We stop the high nitrogen about a month before we expect our first major freeze and fertilize with 0-10-10. Enough can not be said about the importance of lots of nitrogen. We are asked fairly often about why customer's bananas aren't as big as ours; most often it is fertilizer, followed by lack of water. With good growing conditions, a new leaf every 5 days or so is possible.
Winter protection for bananas
Protecting your banana plant can be as laborious as you want. Several methods have been successful. The easiest is to allow the first hard freeze to knock the plant back, then cut the trunk to the ground and mulch over. The mulch should be 6-10 inches deep and can be leaves, bark, straw, or anything else that will provide insulation. Then cover the mulch with plastic to keep the insulating material dry. In the spring, simply remove the plastic. The draw back to this method is the size of the plant, and it most likely will not flower. The most extreme method is to cut off the leaves after the first frost and build a cage around the banana clump, preferably a little taller than the plant. Fill the cage with insulating material and wrap with plastic (Read tips at end of article). Such a procedure is especially good the first winter. The cage technique is not advisable in areas where you rarely get below 20 f and most of your winter is mild. We have lost more bananas due to fungus caused by being wrapped up than we have ever lost to cold. The middle-of-the-road method ( the one we use ) is to do nothing until it is going to be below 20 f for a period of time. We then wrap with household insulation and plastic until the cold spell is over. Then we pull the wrapping, preventing heating and cooling inside the tent. We don't even cut the damaged leaves off until spring. The method you choose depends on your expected low temperatures and the age of the plant. A new banana plant should always be protected the first year. If you live in very cold areas and must leave your banana wrapped for extended periods.
We worked on some wrapped bananas last year to possibly help our friends in very cold areas:
- Remove the leaves to the top of the trunk, don't shorten the trunk is possible
- Spray the trunk with a copper based fungicide and if possible algaecide
- Wrap the trunks with burlap
- Spray the burlap with fungicide
- Try to have your cage quite allot larger than just to the edge of the trunks
- Use dry insulating material
- If you are very, cold wrap the outside of the cage with another insulating material
- Cover the project to keep it dry
- Open the top to allow air to circulate during mild periods