Ok this is actually a little trickier than it sounds, but if you can isolate your males indoors, you can give it a try. First tricky part is harvesting your pollen. Pollen is very sensitive to moisture, so what you do is raise a male or two until bananas start to pop. Once you have a good number popping, cut down plants, wrap loosely in butcher or parchment paper, and sit in a window with good sun to dry. After plants are crunchy dry, gently remove plants and pour the nearly invisible pollen and excess debris into a glass ait tight container ( I use glass cigar tubes as they come with a cork ) add some rice to absorb excess moisture, and set aside till you're ready to pollinate. Find a small bud on a lower branch that you can pull down and away from rest of plant. Away from your intended, dip a small hair paint brush in tube and give it a swirl, and then put brush in a baggie, and carry to your plants. gently remove brush and rub it all over bud, then cover bud with baggie, and wait 20-30 minutes. Oh, yeah all this should be done on as windless a day as possible. After time gas past, be ready with a spray bottle of water, and as soon as you uncover bud, give it and any buds near it a good misting. This will kill any errant pollen and reduce the possibility of pollenating your whole crop. Good luck.