Over the last few years the Rumbling Burn (flows under the A78 to the south of Troon) has become over-run by Himalayan Balsam. This is a small coastal burn and the problem seems to be limited to downstream of the A78, although we haven’t yet checked upstream to find the source.
The photos below show the extent of its domination and provides a snapshot of what all our rivers will look like in years to come if the spread of this invader is not controlled.
Potential routes for its spread are many and agricultural machinery is another to add to the long list. The balsam was growing right up to and in the wheat in this field. The seeds will no doubt find its way into the combine harvester… then onto the next field.
When it grows in dense stands it tends to be single stemmed and tall, like conifers in a plantation, but when it has room to grow it forms a bush. This photo shows a single plant, the stem of which was about 2″ diameter.