Northwest Weeds That Shoot Seeds

Robert Geranium

• Robert geranium (Geranium robertianum) is a forest understory plant with lovely pink to purple flowers and delicate foliage. They hug the ground, growing only 2 to 12 inches tall unless scrambling over support. Robert geraniums can be confused for bleeding heart under forest conditions, but their exploding seed pods are dead giveaways. Shooting seeds up to 20 feet away, sometime even hitting passing animals and people, Robert geranium has earned its Class B noxious weed classification.

Control

• Use gloves when removing Robert geranium because it releases a sticky oil that can cause skin irritation. For a small patch, pull these weeds when you see them appear. String trimmers can kill Robert geranium, but control is often difficult this way. Another solution is to treat the noxious weed with glyphosate, but do not use this chemical if you have plants nearby that you'd prefer to keep alive. In a lawn, broadleaf herbicides containing triclopyr and 2,4-D will kill Robert geranium with little or no harm to the grass.

Scotch Broom

• Scotch broom (Cytisus scoparius) is a beautiful sight, but the plant is highly invasive in the Northwest. These evergreen bushes, reaching heights of 6 to 10 feet, are covered with yellow flowers from March to June. Like Robert geranium, they also are able to eject their seeds up to 20 feet away. Unlike Robert geranium, Scotch broom seeds can remain viable for up to 60 years. Scotch broom often chokes out native plants by forming dense stands.

Control

• Goats have shown success in keeping Scotch broom in check, though the animals must have access to the entire plant. Although goat brush control is earth-friendly, it is also a slow process, sometimes taking many years. You can cut down or mow Scotch broomto help the goats get a jump on control. Chemical control includes glyphosate, imazapyr and triclopyr. Do not apply these chemicals if you choose to use animals to control the plants.