Dahlia ‘Mystery Day’

We’ve had ‘Mystery Day’ on the nursery for a few years now and it always draws a crowd. The flowers are the main event; they’re enormous, fully double blooms of a rich, velvety purple-red, with each petal dipped in bright white. They start opening from mid-summer and will keep coming right up until the first frosts, especially if you keep cutting them for the house.

This is a sturdy, upright plant that typically reaches about a metre in height. It has lush, mid-green leaves that provide a great backdrop for the dramatic flowers. For the best results, give it a spot in full sun with fertile, well-drained soil. It’s a good idea to mix in some well-rotted compost when you plant the tubers.

To get a bushier plant with even more flowers, you can pinch out the main growing tip when the plant is about 30cm tall. Remember to deadhead any spent flowers to encourage more to follow. In our climate, it’s best to lift the tubers after the first frost and store them somewhere dry and frost-free over winter.