Geranium lucidum • Class A

Shiny Geranium grows between 10 to 12 inches high and can tolerate either sun or shade. Seedlings sprout during the first fall rains and continue to grow through fall and winter, forming large patches that begin to bloom in April and May. Its stems are usually tinged bright red, and bear round leaves that are deeply lobed, around 1 ½ inches across, and very waxy, shiny and bright green. Leaves turn vivid red in summer and fall. The five petaled pink flowers grow in pairs on the ends of stalks, at the same height, or in amongst the leaves. 

Shiny geranium establishes quickly in early spring and then dominates the site by pushing out many other early season plants. 

It prefers shade and will invade undisturbed forest understories and form monocultures that replace native plant communities. As soils dry, few other plants are able to establish through the receding weed canopy. 

Shiny Geranium is pollinated by insects and seed. Each seed capsule produces five seeds that are forcefully ejected when ripe. The ability to propel seeds gives this plant the capability of spreading in an upward direction; into the crevices of tree trunks or ascending up a steep terrain. It can produce up to 5 generations in one year. 

Hand pulling is a viable control option where there are small populations or isolated plants. Hoeing or raking may also work if plants are removed after being loosened up. However, disturbing the soil this way may cause new seedlings to emerge, especially when dealing with large populations of Shiny Geranium. 

• Because the species is a low-growing plant, it is often found amongst desirable vegetation. Therefore applications of herbicide should be used only where there are large numbers of plants. 

• Spot spraying with an herbicide containing the active ingredient glyphosate (used in Roundup Pro, or Glyphos) is effective. Glyphosate is non-selective however, and will injure any plants it comes in contact with. Spot applications may be done anytime the plants are actively growing, from early spring to late fall. It is best to treat them before seed capsules mature and produce seed. 

• When using herbicides, carefully read and follow all label instructions and obey all label precautions. (Note: pesticide product registration is renewed annually and product names and formulations may vary from year to year.) 

• Because Shiny Geranium is a class A noxious weed it must be eradicated completely whenever it is found, therefore biological control is not a viable option. 

 Download our Flyer or visit Washington State Noxious Weed Control Board Here. Photo by Leo Michels