I have a large bougainvillea planted in the garden. It is sending up large spikes but leaf margins are brown.?

The plant is huge but not flowering (in April). What to do? When to prune? What fertilizer? It was beautiful last year..don't know what happened.

I have a large bougainvillea planted in the garden. It is sending up large spikes but leaf margins are brown.?
The large 'spikes' are called suckers.





There are some websites you can check over.





Enjoy!