Within wide limits, plants take what N, P , K they need therefore there is little practical difference between fertilizer ratios. You should be more concerned about calcium, sulfate, chloride, and, in the case of banana plants, soluble silicate. When plants grow rapidly, they often develop a calcium deficiency. This is especially true if banana plants are in pots where the sole calcium supply is dolomitic limestone added to soilless potting mixes to raise pH. A calcium deficiency leads to severe deformity of newly grown leaves of banana.

Plants do not need silicon, but banana plants can benefit from it. See

http://www.batphone.com.au/shop/helppages/97-Silicon_article_%20Aust_Bana_Vol.pdf

Thanks for the info. My banana plants are inground, they seem to be growing pretty well, healthy looking. But since I haven't fertilized them in a long time, I was just wondering if now is a good time to add something, but maybe in the heat of summer is not such a good idea.

A good time to fertilize is while growth and photosynthesis are most active. For me, it probably won't be this year. Almost every spring and summer day in the Chicago area has been about 70 deg F and cloudy.

Banana plants in the ground are tough.
You can feed them anything and they will love it! I won't call myself a banana expert, but I have about 15 different types and they are all growing well.

Composted manure is great for them. They will "eat it up!".

I do a "banana" fertilizer (the cheapest I can get, so not always exactly your ratio) a few (4) times a year and long acting 20-20-20 a few times a year also.
When I remember, I give the ones I want to push liquid 20-20-20.

I have clay soil, yet they do fine. In the ground, bananas seem to take anything you throw at them and smile.
Just my opinion- don't worry so much. They like to eat, so feed them!

Thanks for all your input. My soil is alkaline, many of my other fruit tress aren't doing very well, yet the bananas just keep sprouting. All I've added is water twice a week. Originally, I never expected them to grow up so fast and healthy, thinking that the poor soil quality will restrict their growth to an ornamental specimen size in the corner of my yard. They are a fruiting variety (just don't know the name, got it from my cousin). That's why I covered the ground around them with small river rocks/pebbles, and not the preferred compost/manure. I really do want to fertilize them with something that will make them grow crazy, hahaha, I'm loving the shade cast by their broad leaves.

Struwwelpeter I can relate. Here in Winnipeg, Manitoba Canada the mid to high 70's would be warm this year. Some days have only hit the mid 60's F to low 70's. Despite that, my musa basjoo has finally started growing more, maybe one leaf every week. I think sunny days do make a difference, even if it's cool. Maybe it warms the plant up more.

As our soil is very clay-like I amended at planting time with peat moss and composted manure. I have been fertilizing every 10 to 14 days with a mild solution of miracle gro and water, or else a conifer fertilizer that I have (somewhere I read that conifer fertilizer helps prevent petunias from getting yellow so I use that on all the plants once in a while). I usually mix my solution quite a bit milder than the package recommends so maybe this compensates for the more frequent fertilizing.

As you probably know, with flowering plants if you fertilize too much you risk getting lots of lush green growth but no blossoms, but with a banana I don't worry as it will likely never bloom in our short summers anyway. So, I like to think I am just trying to do my best, with the less than ideal weather this year, trying to push out as much growth as possible.

Glen

I can't comment on the fruit trees but bananas, like elephant ears and some other fast-growing tropical herbaceous plants, REALLY respond to fertilizer and especially nitrogen. If it is available, they will grow. In general I've seen recommendations for fertilizer that are highest in nitrogen and potassium, i.e., the first and last numbers. The bottom line is that it is difficult to overfertilize a banana. I give mine a combination of chemical and slow-release organic fertilizers along with generous mulching with compost two or three times a year.