Sounds like a moldy mess to me.

https://duckduckgo.com/?q=banana+peel+fertilizer+potassium&ia=web

A tiny piece of leaf might be okay I the bromeliad tank. You might be able to make a spray-able fertilizer out of soaked leaves. However, composting the peels might be easier in the long run, and people do make compost tea and a weak form of that could be sprayed on. The plants in the wild gain nutrients from leafs and other forest "trash" would fall into their tanks, so mimicking that somehow is an interesting idea.

Banana peels are a great additive to any compost. Lots of potassium and phosphorus. I wouldn't recommend sticking peels into the tank, it will only attract bugs and slime.

If you really want to use banana peels without composting them I'd recommend sun drying them, then crushing them up into small pieces. You can store them in a mason jar when they're bone dry and use them as needed. Mix them in up to 5% by weight with your potting mix. No need to overdo it, bromeliads don't like a rich mixture.

Hi everyone.

Mayfirst – I’m pleased to see you’re not stopping at just
one question ("What is this?"); you say you are “relatively new to
bromeliads and generally all plants”, so what better place to learn all about
them than here on our friendly forum. There are many growers who read these
posts regularly, and for the most part are happy to share any helpful knowledge
with you, all you have to do is ask and if the answer is known, you’ll very
soon get a response, so I encourage you to keep the questions coming as well as
pictures if relevant to the particular post.

The one thing to be aware of when
reading advice from forums and books though, is that people giving this advice
are often from countries other than your own, so you have to make allowances
for seasonal variations.

Now for your question about banana
peel: Banana peel has been used for years in the garden as a natural fertilizer
and nutrient supplement. As well as being rich in phosphorus, and calcium,
along with a host of other minerals your plants need, they also contain Potassium
which is a very important chemical which helps defend plants by creating
thicker cell walls, and making it difficult for germinating fungal spores to
punch a hole through the side of the cell wall and cause disease. It’s also
known to increase the colour in coloured foliage plants as well as increasing
flower production which of course leads to better fruit production.

Potassium is one of the three
main chemicals in most fetilisers; These are Nitrogen, Phosphorous and Potassium
and its main advantage is that it’s beneficial to the “total” plant. In its
commercial form it’s available in various accurate percentages and ratios
specifically designed to benefit specific plants (and usually shown as an
N:P:K ratio on the container). However in its basic natural “banana skin” form
these percentages will vary from fruit to fruit.

I once knew a man who grew
magnificent Staghorn ferns; they were gigantic! When I asked what his secret
was, he said he just threw old (over ripe) banana skins up behind the dead
growth at the rear of the plants and watered them every time he walked past
them. He said you needed to be careful
you didn’t use too much or it would start to smell as they rotted down, (something
you should consider if growing inside the house) but apart from that, the
results were astounding and were there for all to see.

I have been using commercial high potassium liquid
fertilisers for my Billbergias and Neoregelias for about three years now and I’ve
never had better foliage colour or stronger looking plants which rarely show evidence
of any disease, so whether you go the natural route via banana skins or via the
commercially produced forms of granules, soluble powder or liquid, it's up to you; but all will
benefit your plant.

There are various ways of
using banana peel and applying it to your garden. The peels can be chopped and
added directly to the garden, they can be composted, they can be made into a Banana Peel Tea and applied
as a liquid fertiliser, dried and ground into a powder and watered into the
soil to just mention a few, and the list goes on as you will see if you open
the link below to an interesting article.

http://thefrugalchicken.com/10-ways-to-use-banana-peels-in-garden/

I have never added banana skin
to the central tank of a bromeliad and although in theory it should rot down
naturally and become a weak liquid fertiliser, it could also possibly start to
rot the plant if there is any damaged foliage tissue within the tank. For this
reason before I use it I would like to find out more about this method from someone who uses it
and can demonstrate the results.

Of cause if you have several
plants of the same type and can afford to experiment with one. That would be
the best way to try it as you could use one untreated plant as the “control plant”
by which to compare the treated plant against.

I do hope some of this may
help you, unfortunately I do sometimes tend to ramble on one I get wound up.

All the best, Nev.

Thank you for your replies, and being so welcoming to us newcomers! Especially you, Nev! Sharing your experiences and your knowledge is very much appreciated and truly needed, you are literally lifesavers (so I don't end up killing my plants!), and your opinions give me a lot to think about.

As Debby said, in nature bromeliads would get all kinds of stuff in their tanks, and mimicking this sounds like a logical way to fertilize them. That's why I was thinking that this idea wasn't so far-fetched. Here's two quotes from the sites I found this tip on:

" It is not just an old wives' tale that if you put small pieces of banana skin into the cup of a bromeliad, it will bloom better. Bromeliads take in nutrients not only from their roots, but through the water in the cup of the plant. The phosphorous and potassium in banana peels feed the plant and encourage blooms. " [ http://www.gardenguides.com/124855-plants-benefit-banana-skins.html ]

And another site explained it this way:

" To stimulate blooms, large greenhouses use ethelene gas. To force a plant into bloom, the plant should be three-fourths to the same size as the parent. This should force it into flower within a month or two and a new bud will appear. Most non-commercial growers do not yet have this gas. So you must be patient and wait for it to bloom naturally - or you can add a small piece of either a banana peel or apple peel in pups that have reached maturity. Keep cups full of water during this process. Blooming should take place within one to two months. This method produces ethelene gas naturally. " [ http://www.level21nrg.com/id22.html ]

I grow mine indoors since I live in Helsinki, Finland. I have a tiny backyard where during summer I try to give my plants a chance to enjoy some unfiltered sunlight whenever I can, but most of the year they are unfortunately stuck indoors with me in dry air and little sunlight, so anything I can do to make things better for my plants, I try to do. But the backyard being so small, and neighbors being so close, I don't have any place for any kind of composting system unfortunately, so composting isn't really an option for me.

With the banana peels, since I do grow mine indoors, I would definitely worry about the possible smell and flies and such. Drying them up sounds like a better way to go, as littlegatorfarm suggested, but especially at this time of the year we get very little sunlight out here and it'll only get worse until spring. I'd have to buy one of those thingies that dry them for you or use the oven...

As Nev suggested, I'm thinking about trying this "banana tea" route, I wonder if this would work without causing those nasty "side effects"... I plan on trying this with my staghorns, but after reading your opinions on this, I think I'll wait until my bromeliads have some pups and do some testing once I have more than one of each. My t. dyeriana is growing two of them right now, I'm so excited!

But in the meantime if someone decides to try this, please let me know how it goes!