Friend or Foe? Invasive Plants in the Garden

'You'll be sorry!' my friend said as she watched me dig a hole for my newly acquired Acanthus mollis. I know that they have a reputation for being invasive but I'm not one to turn down a free plant and this one had been kindly donated by my kind neighbour. (No he didn't have an ulterior motive, and yes, we did get on. Honestly!)

Half an hour later I had second thoughts and dug it up and replanted it in a more isolated spot, against an ugly bit of fencing where it is now thriving and is not a threat to the flowers in the rest of the garden.

My reluctance to heed her advice was due to being told so many times about plants being invasive. May years ago, I gave in to the voices and spend an entire day digging up seedings of my Euphorbia amygdaloides. Having been told how hard it was to control, I had visions of waking up in the middle of the night and looking out of the window to see a mass of Euphorbia creeping Triffid-like towards the house.

It broke my heart to dig up the seedlings and discard them as if they were weeds. Now, years later, I know better. I collect the seedlings, pot them up and plant them out when they are ready. They are dotted around, allowing their repetition to play a part in the cohesion of the garden. Their dark glossy leaves, endless flowers and defiance of drought and frost have earned them a place here. I wouldn't be without them.

In the the past, plants such as Montbretia (Crocosmia x crocosmiiflora) and Rhododendron ponticum have been welcomed into gardens, but plants can't distinguish between a garden and the field beyond so have escaped at the cost of native species. It's now an offence to plant them in the wild or allow them escape into the wild. There are so many stunning varieties of Crocosmia that are not invasive that you can choose instead. This link will take you to a page on the Gardener's World site which has some suggestions. Link.

Regarding the planting of certain species, the UK Govt says, 'We would expect that where plants listed in Schedule 9 are grown in private gardens, larger scale gardens, estates and amenity areas, reasonable measures will be taken to confine them to the cultivated area so as to prevent their spreading to the wider environment and beyond the landowner’s control.' Link.

The key is to be informed and use common sense and good judgement. A self seeding spreader has a part to play in a large garden but it would be inappropriate for a small courtyard. Getting to know your garden and what works and what doesn't is such an important part of gardening. What works in one won't necessarily work in another.

An afterword. That Acanthus, the one that was in my flowerbed for less than half an hour before I dug it up? A few weeks later, I noticed leaves appearing in that very spot. They looked suspiciously like Acanthus. I can't quite face the, 'I told you so' from my friend, so for now it's just between you and me. I'm heading out to dig out a few roots!