Growing knotweeds
Rhizomes of each of the three knotweed species were collected from a
single location in Michigan (Japanese knotweed: -83.495170, 42.466906,
Bohemian knotweed: -83.7908, 42.6317, and giant knotweed: -88.479681,
46.6442711) in April 2021. Rhizomes were cut to 10-15 cm pieces and
transplanted into 2.5 l plastic pots using a peat and perlite potting
mix (Suremix, Michigan Grower Products). Plants were fertilized with
Osmocote Plus (N:P:K = 15:9:12, ICL fertilizers, USA) once every 2
months and grown at the Michigan State University (MSU) greenhouse
facilities. To propagate knotweeds, 5 cm stem cuttings that contained at
least one node were taken from plants of >50 cm height.
Cuttings were planted similarly as the rhizomes described above and
plants grown from these cuttings were used for experiments. The height
of knotweed plants that were used for this experiment ranged from 20 cm
to 35 cm.