I grew banana in CA, never here. It required a lot of water and fertilizer. By a lot I mean bog like soil and about 2 pounds of fertilizer per month. It grew very fast, got to about 8' and flowered just as I was moving out here :-(

I know banana generally grows where humidity is high. Could be the low humidity is causing a problem. Maybe misting for several hours a day would help.

In their native environment the ground is always soaked. So I don't really understand the drying out between watering thing.

Once growing I think you'd also have to shelter it from wind. They tend to blow over and their leaves shred easily plus the drying effects.

Hey Colin. The problem we have is twofold: soil is generally lacking in sufficient organic matter, and our lack of humidity is a major problem for young bananas. If youre starting with smaller bananas, here is what Ive been successful with: Begin the plants indoors this time of year. Grow them as large as you can before putting them outside. Larger plants have a larger root system to can compensate (well, somewhat) for our lack of humidity. The previous suggestion to use a locally grown plant is also helpful. Plants that come from a higher humidity environment are going to have trouble adapting.
I typically lose plants in late June or early July. Compacted clay soils and low humidity overwhelm the plant, and no amount of watering will allow them to re-hydrate.
Re-visit your soil amendments, and allow them to decompose for the next few months. Amend again before planting with cactus and palm mix. Two feet may have been insufficient. Try going a foot deeper, and ideally, as deep as your back will allow you to go. =)
Meantime, find a plant that you want, hopefully locally grown, and set it outside on humid or mild days, but otherwise in a sunny indoor spot. Water half strength fertilizer twice a month. Come spring, once soil temps are above 60, you can plant. Use a shade for the first month, or until the plant becomes well established. Water as needed, and use the shade cloth on very hot days, and mist the plant as you are able. This will help tremendously, and once established, the plant will do well. Its getting it past that first summer that is the hardest part. Come winter, the plant will defoliate, but will spring back with the warm temps. I still get pretty massive sunburn on mine during the hottest days, and they seem to stop growing above 105. Id recommend protection from the most intense sun.
Until sept., give them all the fertilizer they can handle (once established), and make sure the soil drains very, very well. With insufficiently amended soil, the water that they need and high temps breed bacteria and fungus also, so watch out for root rot on your smaller plants. If they dont spring back on humid or overcast days, or at least a little bit at night, then take it back inside in a pot with well draining soil.
Hope this helps. Once established in good soil, bananas do really well here. Generally, it takes two years to get fruit, but they pup nicely, and make an awesome addition to the landscape.
DD

Thanks for the good info guys.

I grow mine in a raised bed that I built. It is located between my house and against a wall that goes into my back yard. My house is side-entrance so between the house and a wall that goes to my backyard on the other side. Late day exposure is to the west but the roots and raised bed they are behind a wall so their stalks never seen direct beating sun.

I used cactus mix, some peat, perlite, and Gro-mulch. No problems here. Drainage is great from the raised bed. They send up pups constantly.

Make a friend that grows bananas and they can give you all the bananas you want.

I grow Mysore, Manzana, and Rajapuri. The Rajapuris are the best and more wind resistent and far better looking. They also fruit sooner.

I don't get burnback in my area that much where they totally defoliate. I've had some damage in winter, but not that.

You guys in zone 9a (USDA), are you sure about that? Unless you are in Tucson or a very outlying area, Phoenix has graduated to zone 10 in the city center (expands every year now) or at least 9b in the metro area. There are 'cold pockets' though. I prefer just using sunset zones where Phoenix is 13 and Tucson is zone 12.

Good luck.

Thanks to all of you for giving me your advice. I think that what I can glean from your postings is that there are a combination of factors involved with getting bananas successfully established here in Phoenix. Mine were mail-order from Florida and the advice about keeping them more humid to begin with was interesting ( the point, however obvious, had escaped me). I think the point made about limiting direct sun for the first few months of growth was a pertinent one. I believe that mine may have had less of an issue of being under or over-watered and perhaps sufferred more from being scorched by intense sunlight, albeit just the morning-early pm exposure. The leaves of my young bananas look like someone actually took a torch to them. I have invested in some shade cloth and will erect a shade cloth frame over them. The advice about 'digging deeper' was an 'eye opener'. I am still plagued with Crab and Bermuda grass. The latter is initially easier to get rid of, both of them are completely invasive and a serious problem. A raised bed seems like a good idea, but since it would be adjacent to a lawn I know that it would have to be almost hermetically sealed! I am tempted to go in for a 'complete ground kill' solution. However I have no confidence that this would adequately succeed and have no wish to poison the soil or the water-table. These grasses are driving me nuts - if I'm not nuts enough already! Finally 'good drainage and well conditioned, fertile soil' were key to mention. The thoughts of digging down another foot, is not on my wish list but I recognise that this would be an advantage. I shall look at this too - maybe hire a soil tiller - rotivator. I used to use a perlite-vermiculite mix to germinate seedlings for my NFT hydroponic system back in the UK. I haven't seen either of these here yet, then again I haven't looked for them either. Thanks again to everyone and feel free to email me or post further. Regards, Colin. colinmonaghan@cox.net

You guys have me looking around. I saw banana in a backyard I think around 7 St & Northern. Maybe 5-6 plants about as tall as the house. Looked very healthy except for the split leaves which would be pretty normal. Young plants would have been protected from the sun until they got above the roof line.

I don't get the poison route for grass unless used in combination with a structural change like laying sod, installing barriers, etc... Otherwise it's right back. I've tried it a couple of times and it seemed like more work than weeding, at least in small areas.

A thick organic mulch would help the banana and slow grass expansion.