I'd really be grateful if someone could suggest how to stop pigeons landing on my balcony & making nests on my verandah. I've got some spikes to deter them but they seem determined to find a free spot every morning and I'm fed up of clearing up their mess.
Have you watched 'A Life of Grime' on BBC1? This is a regular problem, especially on council flat balconies. The only way they seem to have to stop the winged vermin, is to totally net off the 'open' side of the balcony to stop them getting in. Obviously this will impair your view, but you have to decide which you would rather lose.
You could try stretching some fishing twine over the landing sites - they will feel this when they come in to settle, and it should deter them. Otherwise, what about some anti-bandal paint, which provides a slippery surface, which again will deter them. Good luck.
Try a black bin bag cut into strips like bunting, it flaps and waves about and may deter them, my friend uses this method and is reasonably successful, though some of the streetwise guys ignore it and land on her balcony just the same.