Pushing my Persicaria

When we moved to Springfield there was an old, overgrown mixed border exactly where our new greenhouse was going to be built.  So, I rescued what I could and we finished up with pots full of plants, most of which I did not know the name of.  Later, a friend told me that one of the pots was a plant called Persicaria (Polygonum) and I have kept the clump going for years, from pot to ‘nursery bed’, then I split it and put back into pots, whilst I waited for a suitable final planting position.

Persicaria has a long flowering period from spring to midsummer and I have discovered that this plant is called a Knotweed for a good reason.  It has a vigorous habit and many people consider it to be a weed.  It is pretty though and has bottlebrush-like, tiny mauve-pink flowers packed tightly together on thin stems, above the semi-evergreen dock-like foliage.
 
Apparently this plant is an excellent choice for an acid, damp garden and the best planting position is at the edge of a pond or in a bog garden, where it quickly spreads, forming impressive colonies up to 1m wide.  However, in our garden it has always been planted in dry positions as well as pots which have received nothing more than a splash of water when remember.  It has survived and flowered, but has not taken off hugely.  I have been left wondering if planting it somewhere less hospitable slows it down so it cannot take over a border.

We have semi-shady gaps between the raised beds and trellis panels that screen the composting area.  I have planted ivy, ferns and a lovely evergreen honeysuckle which was recommended by a gardener at a plant fair.  We have great hopes for Lonicera japonica ‘Acumen’ because he said it is tough, really tough and offers more interest than more ivy.

Last year I also planted out a pot of Persicaria in the gap.  I admit that this was brave because it likes sun and damp and this area is shady a lot of the time and dry!  Doc raised his eyebrows and thought it would die.  He said I would be re-planting the area with something else.  However, this spring I am feeling smug because my Persicaria is a very happy plant and growing nicely and more importantly, is very well behaved.  Every time I go to the compost heap I give it a nod of approval.  I gave it a chance and it is doing well.

So my next experiment is planting a patch of the Persicaria in the very sunny, dry corner of the bed at the end of the lawn.  It is an area plagued with weeds and there are boring overgrown shrubs which belong on a roundabout, as well as ivy.  I am hoping the Persicaria will slow down the weed growth and at least bring some colour and compete with the ‘motorway service’ planting scheme. Anyway, it is worth a try.

Experimenting and trying things out is one of the great joys of gardening.  Most of us take the trouble reading the instructions on plant labels.  Whilst this advice is generally the best, sometimes I like to test the plant and push the boundaries.  After all, my Persicaria was free, I won’t lose money by trying clumps here and there and I might discover that far from being picky, this plant is much more versatile.

I will be keeping an eye on my Persicaria though.  Any sign that it is threatening other plants and it will be banished forever, but at least I am open minded.