My Rose of Sharon shrubs, I have three in a row, are at least twenty feet tall, and profusely bloom mid-July through August, by mid September the last few blooms stop. So never have they bloomed a single flower in Autumn. I would also add, that I too have a trumpet vine, as the first commenter, that was given to me twenty years ago at least, that is so invasive, it has shoots coming up every where. I can not rid my property of it, nor chop it down, without it coming back even more aggressive. Here in lies the rub; it, nor any of the hundreds of offshoots, have ever bloomed one trumpet flower, ever. So, there must be something too this, issue of non flowering trumpet vines. I can not find, any solution, that will work, and make them flower.
My Rose of Sharon shrubs, I have three in a row, are at least twenty feet tall, and profusely bloom mid-July through August, by mid September the last few blooms stop. So never have they bloomed a single flower in Autumn. I would also add, that I too have a trumpet vine, as the first commenter, that was given to me twenty years ago at least, that is so invasive, it has shoots coming up every where. I can not rid my property of it, nor chop it down, without it coming back even more aggressive. Here in lies the rub; it, nor any of the hundreds of offshoots, have ever bloomed one trumpet flower, ever. So, there must be something too this, issue of non flowering trumpet vines. I can not find, any solution, that will work, and make them flower.