Day: October 31, 2021

It’s Halloween, so it’s time to post about my garden monster. It looks innocent enough and the daisy-like flowers are very attractive. But it’s huge and spreading, so likely to smother many of the plants around it.

I bought this some years ago as a small plant labelled only as a perennial sunflower, no other details. For the first years after planting, the sunflower didn’t grow much. It was in an unfavourable position, with very poor soil and several shrubs close by. It reached about 3 ft. tall, with narrow stems and leaves and carried pretty yellow flowers in the autumn.

Last year I decided to move a piece to an area that was intended to have a sort of prairie-style planting with coneflowers, grasses, kniphofias and verbena bonariensis. I waited to see if the plant would survive the move and got a shock – it’s growth habit had changed entirely!

The new position has much better soil and suddenly this plant was shooting up. And it was bulky too. The leaves were no longer narrow and dainty – they instead grew to about 7 or 8 inches long and were wide, more like the annual sunflowers. The stems kept growing, with no sign of flower buds for a long time. Eventually flower buds started to appear and the stems finished growing as they reached the impressive height of 8 ft.

Yikes! I’d made a big mistake. This was no longer the dainty-looking sunflower that had been struggling on the other side of the garden. The improved position had allowed my unnamed plant to reach it’s true size. It was now a massive monster that threatened to engulf the other plants.

Because the original plant was so much smaller than it was supposed to be, I hadn’t been able to identify the variety. Now I think that it is Helianthus tuberosus – the Jerusalem artichoke. Or it could possibly be a Maximilian sunflower, which is available as seed in the UK. Whatever it is, I am going to have to dig it all up before it can spread any further.

So that’s my scary tale for Halloween…but I’m happy to say that my other helianthus – ‘Lemon Queen’ (pictured below) is much better-behaved. It is just under 6 ft. tall and seems to stay in a large clump, rather than trying to spread itself everywhere. The bees seem to prefer this one too!