There are two invasive weeds we pull while walking through our neighborhood. One is bindweed, the other Ailanthus altissima (tree of heaven).

Ailanthus grows everywhere – under porches, in sidewalk cracks, just about anywhere it can put down it’s long taproot. And if you let it grow too tall, it’s almost impossible to eradicate.

In a recent WPost article however, Harvard biologist Peter Del Tridici defended a tree with very few fans. Del Tridici points to the the benefits this tree provides – shade, fixing carbon, producing oxygen and some greenery in blighted areas.  They are not invasive, he writes, but rather “spontaneous.”

Granted, some of the services provided by this tree are beneficial. But on the “ailanthus as invasive” side, ailanthus:

  • is allelopathic – leaks toxins into the soil that prevent other species from growing nearby
  • crowds out other species
  • rightfully deserves the name “stinking sumac”
  • has an aggressive root system that can damage pavement, foundations and water system

So although Ailanthus  has nine fans on Facebook (plus Del Tridici) we will continue to be stealth weeders of this noxious weed.