Tamarix: One of the Dirty Dozen
Don't be fooled. I used to wonder why it wasn't more widely planted. Now I know that tamarisk is one of the Nature Conservancy's Dirty Dozen most invasive ornamental plants – and one of the World Conservation Union's 100 worst alien invaders.
Already a big problem south of the border, the threat hasn't yet reached Ontario, from what I can see. However, western provinces such as Manitoba (see link above) and Alberta are issuing warnings. Most at risk are areas with ample water, such as riverbanks, as the tamarisk has a wicked thirst – up to 750 litres (200 gallons) per day. That's per day.
The tamarisk shrub or tree produces salt secretions that make growing conditions inhospitable to other plants. In that way, it muscles out native riparian species.
A quick Google search shows that Tamarix is still available for purchase in local nurseries. As pretty as these frothy flowers are, I'd think twice before buying.