Natural fertiliser with banana peels

I genuinely have no idea whether this will do any good. I'm keen to hear from others who have tried this!

Some internet research suggests my efforts may be in vain; however, I thought I would give this a go. It's an idea from Jen Chillingsworth's book Live Green.

So, banana's contain potassium, calcium and phosphorus, which are all important nutrients for some plants. I am using this mix mainly for the tomatoes.

When we eat bananas (organic - i.e. not sprayed with pesticides), we pop the peels into a glass jar and cover with water and leave for 2 - 4 days.

I then use this mix to water the tomato plants in the greenhouse, and compost the peels.